Trane WEHC, WSHC, WFHC, WXHC, WLHC Installation and Maintenance Manual

Page 1

Installation, Operation, and Maintenance

IntelliPak™ II

Commercial Rooftop Air Handlers with CV, VAV, or SZVAV Controls

‘F0’ and later design sequence

Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of heating, ventilating, and air-conditioning equipment can be hazardous and requires specific knowledge and training. Improperly installed, adjusted or altered equipment by an unqualified person could result in death or serious injury. When working on the equipment, observe all precautions in the literature and on the tags, stickers, and labels that are attached to the equipment.

October 2011 RT-SVX28E-EN

WEHC WSHC WFHC WXHC WLHC

SAFETY WARNING

Page 2

Warnings, Cautions and Notices

Warnings, Cautions and Notices. Note that warnings, cautions and notices appear at

appropriate intervals throughout this manual. Warnings are provide to alert installing contractors to potential hazards that could result in death or personal injury. Cautions are designed to alert personnel to hazardous situations that could result in personal injury, while notices indicate a situation that could result in equipment or property-damage-only accidents.

Your personal safety and the proper operation of this machine depend upon the strict observance of these precautions.

Read this manual thoroughly before operating or servicing this unit.

ATTENTION: Warnings, Cautions and Notices appear at appropriate sections throughout this

literature. Read these carefully:

WARNI NG

CAUTIONs

NOTICE:

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

Indicates a potentially hazardous situation which, if not avoided, could result in minor or moderate injury. It could also be used to alert against unsafe practices.

Indicates a situation that could result in equipment or property-damage only accidents.

Important Environmental Concerns!

Scientific research has shown that certain man-made chemicals can affect the earth’s naturally occurring stratospheric ozone layer when released to the atmosphere. In particular, several of the identified chemicals that may affect the ozone layer are refrigerants that contain Chlorine, Fluorine and Carbon (CFCs) and those containing Hydrogen, Chlorine, Fluorine and Carbon (HCFCs). Not all refrigerants containing these compounds have the same potential impact to the environment. Trane advocates the responsible handling of all refrigerants-including industry replacements for CFCs such as HCFCs and HFCs.

Responsible Refrigerant Practices!

Trane believes that responsible refrigerant practices are important to the environment, our customers, and the air conditioning industry. All technicians who handle refrigerants must be certified. The Federal Clean Air Act (Section 608) sets forth the requirements for handling, reclaiming, recovering and recycling of certain refrigerants and the equipment that is used in these service procedures. In addition, some states or municipalities may have additional requirements that must also be adhered to for responsible management of refrigerants. Know the applicable laws and follow them.

WARNING

Proper Field Wiring and Grounding Required!

All field wiring MUST be performed by qualified personnel. Improperly installed and grounded field wiring poses FIRE and ELECTROCUTION hazards. To avoid these hazards, you MUST follow requirements for field wiring installation and grounding as described in NEC and your local/state electrical codes. Failure to follow code could result in death or serious injury.

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Personal Protective Equipment (PPE) Required!

Installing/servicing this unit could result in exposure to electrical, mechanical and chemical hazards.

• Before installing/servicing this unit, technicians MUST put on all Personal Protective

• When working with or around hazardous chemicals, ALWAYS refer to the appropriate MSDS

• If there is a risk of arc or flash, technicians MUST put on all Personal Protective Equipment

Failure to follow recommendations could result in death or serious injury.

Overview of Manual

Notes:

• This document is the customer property and must be retained by the unit owner for use by

• The procedures discussed in this manual should only be performed by qualified, experienced

This booklet describes proper installation, start-up, operation, and maintenance procedures for Casings A-C rooftop air handlers designed for Constant Volume (CV), Single Zone Variable Air Volume (SZVAV) and Variable Air Volume (VAV) applications. By carefully reviewing the information within this manual and following the instructions, the risk of improper operation and/ or component damage will be minimized.

Note: One copy of the appropriate service literature ships inside the control panel of each unit.

It is important that periodic maintenance be performed to help assure trouble free operation. Should equipment failure occur, contact a qualified service organization with qualified, experienced HVAC technicians to properly diagnose and repair this equipment.

Warnings, Cautions and Notices

WARNING

Equipment (PPE) recommended for the work being undertaken. ALWAYS refer to appropriate MSDS sheets and OSHA guidelines for proper PPE.

sheets and OSHA guidelines for information on allowable personal exposure levels, proper respiratory protection and handling recommendations.

(PPE) in accordance with NFPA 70E or other country-specific requirements for arc flash protection, PRIOR to servicing the unit.

maintenance personnel.

HVAC technicians.

RT-SVX28E-EN 3

Page 4

Model Number Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Commonly used Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Input Devices and System Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Unit Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Unit Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Pre-Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Overview of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Constant Volume (CV) and Variable Air Volume (VAV) Units . . . . . . . . . 13

Constant Volume (CV) Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Variable Air Volume (VAV) Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Single Zone Variable Air Volume (SZVAV) Only . . . . . . . . . . . . . . . . . . . 17

Space Temperature Averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Unit Control Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

General Unit Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Rigging the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Main Electrical Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Field Installed Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Requirements for Electric Heat Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Requirement for Gas Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Requirements for Hot Water Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Requirements for Steam Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Requirements for Chilled Water Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . 30

O/A Pressure Sensor and Tubing Installation (all units with Statitrac) . . 30

Condensate Drain Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Units with Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Removing Supply and Exhaust Fan Shipping Channels . . . . . . . . . . . . . 31

Spring Isolators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

O/A Sensor and Tubing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Units with Statitrac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Roof Curb and Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Pitch Pocket Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

If a Trane Curb Accessory Kit is not used . . . . . . . . . . . . . . . . . . . . . . . . . 37

Field Converting Horizontal Ductwork from Right to the Left Side . . . . . 38

Unit Rigging and Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Lifting the External Piping Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Gas Heat Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4 RT-SVX28E-EN

Page 5

Connecting the Gas Supply Line to the Furnace Gas train . . . . . . . . . . . 43

Hot Water Heat Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Steam Heat Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

General Coil Piping and Connection Recommendations . . . . . . . . . . . . . . . . 49

Chilled Water Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

General Coil Piping Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Coil Winterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

External Piping Enclosure Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Disconnect Switch w/External Handle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Electric Heat Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Main Unit Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Power Wire Sizing and Protection Devices . . . . . . . . . . . . . . . . . . . . . . . . 61

Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Field Installed Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Controls using 24 VAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Controls using DC Analog Input/Outputs . . . . . . . . . . . . . . . . . . . . . . . . . 65

Constant Volume System Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Variable Air Volume System Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Constant Volume or Variable Air volume System Controls . . . . . . . . . . 66

Emergency Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Ventilation Override Module (VOM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Temperature vs. Resistance Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Cooling Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Gas Heating Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Electric Heat Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

CV Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

VAV Occupied Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Demand Control Ventilation Sequence of Operation . . . . . . . . . . . . . . . . 84

Return Fan Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Wet Heat Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Verifying Proper Fan Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

System Airflow Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Exhaust Airflow Measurement (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . 91

Traq™ Sensor Airflow Measurement (Optional with all units equipped with

an economizer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Supply Fan (with or without Variable Frequency Drive) . . . . . . . . . . . . . . . . 93

Exhaust Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Return Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Component Static Pressure Drops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

RT-SVX28E-EN 5

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Unit Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Economizer Damper Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

To Adjust the Fresh Air Damper Travel . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Chilled Water Cooling Startup (Constant Volume & Variable Air Volume Systems)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Electric, Steam and Hot Water Start-Up (Constant Volume & Variable Air Volume Systems)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Gas Furnace Start-Up (Constant Volume and Variable Air Volume Systems)

Two Stage Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Full Modulating Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

. . . . . . . . . . . . . . . . . 105

Final Unit Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Fan Belt Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

VFD Programming Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Monthly Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Cooling Season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Heating Season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Coil Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Final Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Warranty and Liability Clause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

6 RT-SVX28E-EN

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Model Number Descriptions

WEHCA0040A0411F70001A0000A0D0A00000000

1 2 3 4 567 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

DIGIT 1 — UNIT TYPE

W Self-Contained (Packaged

Air Handler)

DIGIT 2 — UNIT FUNCTION

E Electric Heat F Natural Gas Heat L Hot Water Heat S Steam Heat X No Heat

DIGIT3—SYSTEMTYPE

H Single Zone

DIGIT 4 — DEVELOPMENT SEQUENCE

C Third

DIGIT 5 — UNIT SIZE

A 16,000 - 31,000 CFM B 20,000 - 38,000 CFM C 20,000 - 45,000 CFM

DIGIT6—COOLING COIL

0 No Cooling Coil 2 2 Row Chilled Water 4 4 Row Chilled Water 6 6 Row Chilled Water 8 8 Row Chilled Water

DIGIT 7 — CHILLED WATER COIL FIN SERIES

0 No Chilled Water Coil A Series 80 without Turbulators B Series 80 with Turbulators C Series 108 without Turbulators D Series 108 with Turbulators E Series 144 without Turbulators F Series 144 with Turbulators G Series 168 without Turbulators H Series 168 with Turbulators

DIGIT 8 — VOLTAGE SELECTION

4 460/60/3 XL 5 575/60/3 XL

DIGIT 9 — HEAT CAPACITY SELECTION

0 No Heat 1 Electric Heat 90 kW 2 Electric Heat 140 kW 3 Electric Heat 265 kW 4 Electric Heat 300 kW A Low Gas Heat - 2 stage B Medium Gas Heat - 2 stage C High Gas Heat - 2 stage D Low Gas Heat - Modulating E Medium Gas Heat - Modulating F High Gas Heat - Modulating

Low Heat Options

H Low Heat - 1.25 in. (32mm) Valve J Low Heat - 1.5 in. (38mm) Valve K Low Heat - 2.0 in. (50mm) Valve L Low Heat - 2.50 in. (64mm) Valve M Low Heat - 3.0 in. (76mm) Valve

High Heat Options

P High Heat - 1.25 in.(32mm) Valve Q High Heat - 1.5 in. (38mm) Valve R High Heat - 2.0 in. (50mm) Valve T High Heat - 2.50 in. (64mm) Valve U High Heat - 3.0 in. (76mm) Valve

DIGIT 10 & 11— DESIGN SEQUENCE

DIGIT 12 — UNIT CONFIGURATION SELECTION

4 1 Piece Unit - without Blank

Section

5 1 Piece Unit with 4 ft. Blank

Section

6 1 Piece Unit with 8 ft. Blank

Section

DIGIT 13 — AIRFLOW DIRECTION

1 Downflow Supply/Upflow Return 2 Downflow Supply/Horizontal End

Return

3 Downflow Supply/Horizontal

Right Return

4 Right Side Horizontal Supply/

Upflow Return

5 Right Side Horizontal Supply/

Horizontal End Return

6 Right Side Horizontal Supply/

Horizontal Right Return

DIGIT 14 — FAN MOTOR SELECTION

1 Standard Fan 3 Standard Fan w/ TEFC Motor

DIGIT 15 — SUPPLY FAN MOTOR SELECTION

F15Hp G20Hp H25Hp J30Hp K40Hp L50Hp M60Hp N75Hp

DIGIT 16 — SUPPLY FAN RPM SELECTION

7700 8800 9900 A1000 B1100 C 1200 D 1300 E 1400 F 1500 G 1600 H 1700 J 1800 K 1900 L2000

DIGIT 17 — EXHAUST/RETURN FAN OPTIONS

0 None 1 High CFM Exhaust w/o Statitrac

CV Only

2 Low CFM Exhaust w/o Statitrac

CV Only

3 High CFM Exhaust w/o VFD w/

Statitrac

4 Low CFM Exhaust w/o VFD w/

Statitrac

5 High CFM Exhaust w/ VFD w/

Bypass w/ Statitrac

6 Low CFM Exhaust w/ VFD w/

Bypass w/ Statitrac

7 High CFM Exhaust w/ VFD w/o

Bypass w/ Statitrac

8 Low CFM Exhaust w/ VFD w/o

Bypass w/ Statitrac A Return w/o Statitrac CV Only C Return w/ VFD w/ Bypass w/

Statitrac E Return w/ VFD w/o Bypass w/

Statitrac

DIGIT 18 — EXHAUST/RETURN FAN MOTOR SELECTION

0 None D 7.5 Hp E10Hp F15Hp G20Hp H25Hp J30Hp K40Hp L50Hp M60Hp

RT-SVX28E-EN 7

Page 8

Model Number Descriptions

DIGIT 19 — EXHAUST/RETURN RPM SELECTION

0 None 3300 4400 5500 6600 7700 8800 9900 A1000 B1100 C 1200 D 1300 E 1400

DIGIT 20 — SYSTEM CONTROL SELECTION

1 Constant Volume (Zone

Temperature Control) 2 VAV (Discharge Air Control) 4 VFD Supply w/o Bypass

(Discharge Air Control) 5 VFD Supply w/Bypass (Discharge

Air Control) 6 Single Zone VAV w/VFD w/o Bypass

(Zone Temperature Control) 7 Single Zone VAV w/VFD w/Bypass

(Zone Temperature Control)

DIGIT 21 — FRESH AIR AND ECONOMIZER OPTIONS/ CONTROLS

A 0 - 25% Motorized Damper B Econ w/Dry Bulb C Econ w/Reference Enthalpy D Econ w/Comparative Enthalpy E Econ w/Fresh Air Measure /Dry

Bulb F Econ w/ Fresh Air Measure /Ref

Enth G Econ w/Fresh Air Measure /Comp

Enth H Econ w/DCV /Dry Bulb J Econ w/DCV /Ref Enth K Econ w/DCV /Comp Enth

DIGIT 22 — DAMPER OPTION

0 Standard 1 Low Leak 2 Ultra Low Leak

DIGIT 23 — PRE COOLING COIL FILTER SELECTION

0 2" High Efficiency Throw Away 1 2" Throw Away Rack / Less Filters 2 90 - 95%, Bag Filters w/ Pre Filters 3 Bag Filter Rack / Less Filters 4 90 - 95%, Cartridge Filters w/

Pre Filters 5 Cartridge Rack / Less Filters 6 90 - 95% Low PD Cartridge w/

Pre Filters 7 Low PD Cartridge Rack / Less

Filters

DIGIT 24 — BLANK SECTION APPLICATION OPTIONS

0 None A 90 - 95% Bag w/Pre Filters B 90 - 95% Low PD Cartridge w/

Pre Filters

C 90 - 95%, Cartridge Filters w/

Pre Filters

D 90 - 95% Hi Temp Cartridge w/

Pre Filters E HEPA w/Pre Filters F Hi Temp HEPA w/Pre Filters

DIGIT 25 — FUTURE DEVELOPMENT

DIGIT 26 — UNIT MOUNTED POWER CONNECTION SELECTION

A Terminal Block B Non Fused Disconnect C Non Fused Disconnect w/

Pwrd conv outlet D Circuit Breaker w/ SCWR E Ckt Brkr w/ SCWR/ Pwrd conv

outlet

DIGIT 27 — (FUTURE DEVELOPMENT)

0 None

DIGIT 28 — COIL/DRAIN PAN

D No Drain Pan E Galvanized Drain Pan

DIGIT 29 — CHILLED WATER COIL VALVE

0 None A 1.5" Cooling Valve B 2" Cooling Valve C 2.5" Cooling Valve D 3" Cooling Valve

DIGIT 30 — (FUTURE DEVELOPMENT)

0 None

DIGIT 31 — (FUTURE DEVELOPMENT)

0 None

DIGIT 32 — HIGH DUCT TEMPERATURE THERMOSTAT

0 None 1 High Duct Temp Thermostat

DIGIT 33 — REMOTE HUMAN INTERFACE

0 None 1 RHI & IPCB 2 IPCB

DIGIT 34 — MODULE OPTIONS

0 None A 0-5 Volt GBAS B 0-10 Volt GBAS C 0-5 / 0-10 Volt GBAS F LonTalk Communication Interface

(LCI) D Ventilation Override G 0-5 Volt GBAS / Ventilation

Override H 0-10 Volt GBAS / Ventilation

Override J 0-5 / 0-10 V GBAS / Ventilation

Override L LCI & Ventilation Override M BACnet Communication

Interface (BCI) N BCI & Ventilation Override

DIGIT 35 — ZONE SENSOR OPTION

0 None A Dual Setpoint w/Man/Auto

Changeover B Dual Stpt w/Man/Auto Chgovr &

Sys Lights C Room Sensor w/Timed Override

& Cancel D Room Snsr w/TO & Cancel &

Local Stpt Adj G VAV w/System Lights L Programmable Night Setback

DIGIT 36 — AGENCY APPROVAL OPTION

0 None 1 cULus

DIGIT 37 — SERVICE ENHANCEMENTS

0 Single Side Access Doors A Dual Side Access Doors B Single Side Access Doors /

Marine Lights C Dual Side Access Doors / Marine

Lights

DIGIT 38 — BELT GUARDS/ BURGLAR BARS/MARINE LIGHTS

0 None 1 Belt Guards 2 Burglar Bars 3 Belt Guards / Burglar Bars

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General Information

Unit Nameplate

One Mylar unit nameplate is located on the outside upper left corner of the control panel door. It includes the unit model number, serial number, electrical characteristics, weight, refrigerant charge, as well as other pertinent unit data. A small metal nameplate with the Model Number, Serial Number, and Unit Weight is located just above the Mylar nameplate, and a third nameplate is located on the inside of the control panel door.

Precautionary Measures

• Avoid breathing fiberglass dust

• Use a NIOSH approved dust/mist respirator

• Avoid contact with the skin or eyes. Wear long-sleeved, loose-fitting clothing, gloves, and eye protection

• Wash clothes separately from other clothing: rinse washer thoroughly

• Operations such as sawing, blowing, tear-out, and spraying may generate fiber concentrations requiring additional respiratory protection. Use the appropriate NIOSH approved respiration in these situations.

First Aid Measures

Eye Contact

– Flush eyes with water to remove dust. If symptoms persist, seek medical attention.

Skin Contact

– Wash affected areas gently with soap and warm water after handling.

Commonly used Acronyms

For convenience, a number of acronyms and abbreviations are used throughout this manual. These acronyms are alphabetically listed and defined below.

• AHU = Air Handler Unit • LCI-I = LonTalk Communication Interface for IntelliPak

• BAS = Building automation systems • LH = Left-hand

• BCI = BACnet Communication Interface module • MWU = Morning warm-up

• CFM = Cubic-feet-per-minute • NSB = Night setback

• CV = Constant volume • O/A = Outside air

• CW = Clockwise • psig = Pounds-per-square-inch, gauge pressure

• CCW = Counterclockwise • R/A = Return air

• E/A = Exhaust air • RH = Right-hand

• ECEM = Exhaust/comparative enthalpy module • RPM = Revolutions-per-minute

• F/A = Fresh air • RTM = Rooftop module

• GBAS = Generic building automation system • S/A = Supply air

• HGBP = Hot gas bypass • SZ = Single-zone (unit airflow)

• HI = Human Interface • SZVAV = Single zone variable air volume

• HVAC = Heating, ventilation and air conditioning • UCM = Unit control modules

• I/O = Inputs/outputs • VAV = Variable air volume

• IOM = Installation/operation/ maintenance manual • VCM = Ventilation control module

• IPC = Interprocessor communications • VOM = Ventilation override module

• IPCB = Interprocessor communications bridge • w.c. = Water column

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General Information

Unit Description

Each Trane commercial, single-zone rooftop air handler ships fully assembled from the factory.

An optional roof curb, specifically designed for the W_HC units is available from Trane. The roof curb kit must be field assembled and installed according to the latest edition of the roof curb installation manual.

Trane Commercial Rooftop Air Handlers are controlled by a microelectronic control system that consists of a network of modules and are referred to as Unit Control Modules (UCM). The acronym UCM is used extensively throughout this document when referring to the control system network.

These modules through Proportional/Integral control algorithms perform specific unit functions which provide the best possible comfort level for the customer.

They are mounted in the control panel and are factory wired to their respective internal components. They receive and interpret information from other unit modules, sensors, remote panels, and customer binary contacts to satisfy the applicable request for economizing, mechanical cooling, heating, and ventilation. Refer to the following discussion for an explanation of each module function.

Rooftop Module (RTM - Standard on all units)

The rooftop Module (RTM) responds to cooling, heating, and ventilation requests by energizing the proper unit components based on information received from other unit modules, sensors, remote panels, and customer supplied binary inputs. It initiates supply fan, exhaust fan, exhaust damper, or variable frequency drive output, and economizer operation based on that information.

Human Interface Module (HI - standard on all units)

The Human Interface module enables the operator to adjust the operating parameters for the unit using a 16 key keypad. The 2 line, 40 character LCD screen provides status information for the various unit functions as well as menus for the operator to set or modify the operating parameters.

Heat Module (used on heating units)

The Heat module, upon receiving a request for Heating, energizes the appropriate heating stages or strokes the Modulating Heating valve as required.

Table 1. Resistance input vs. setpoint temperature

RTM cooling or heating setpoint

input used as the source for a

ZONE temp setpoint (F)

40 40 1084

45 45 992

50 50 899

55 55 796

60 60 695

65 65 597

70 70 500

75 75 403

80 80 305

n/a 85 208

n/a 90 111

RTM cooling setpoint input used as the source for SUPPLY AIR temp setpoint cooling (F)

Resistance

(Ohms) Max.

Tolerance 5%

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General Information

Table 2. Resistance value vs. system operating mode

Resistance applied to RTM MODE

input Terminals (Ohms) Max.

Tolerance 5% Constant Volume Units

2320 Auto Off

4870 Auto Cool

7680 Auto Auto

10770 On Off

13320 On Cool

16130 On Auto

19480 Auto Heat

Ventilation Override Module (VOM - Optional)

Important: The ventilation override system should not be used to signal the presence of smoke

caused by a fire as it is not intended nor designed to do so.

The Ventilation Override module initiates specified functions such as; space pressurization, exhaust, purge, purge with duct pressure control, and unit off when any one of the five (5) binary inputs to the module are activated. If more than one ventilation sequence is activated, the one with the highest priority is initiated.

Interprocessor Communications Board (IPCB - Optional used with the Optional Remote Human Interface)

The Interprocessor Communication Board expands communications from the unit UCM network to a Remote Human Interface Panel. DIP switch settings on the IPCB module for this application should be; Switches 1 and 2 "Off", Switch 3 "On".

Lontalk/BACnet Communication Interface Module (LCI/BCI - Optional - used

™

on units with Trane ICS

or 3rd party Building Automation Systems)

The LonTalk/BACnet Communication Interface modules expand communications from the unit UCM network to a Trane Tracer Summit™ or a 3rd party building automation system and allow external setpoint and configuration adjustment and monitoring of status and diagnostics.

Exhaust/Comparative Enthalpy Module (ECEM - Optional used on units with Statitrac and/or comparative enthalpy options)

The Exhaust/Comparative Enthalpy module receives information from the return air humidity sensor, the outside air humidity sensor, and the return air temperature sensor to utilize the lowest possible humidity level when considering economizer operation. In addition, it receives space pressure information which is used to maintain the space pressure to within the setpoint controlband. Refer to Figure 1, p. 12 for the Humidity vs. Voltage input values.

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General Information

Figure 1. Humidity vs. current

Ventilation Control Module (VCM)

The Ventilation Control Module (VCM) is located in the filter section of the unit and is linked to the unit UCM network. Using a "velocity pressure" sensing ring located in the fresh air section allows the VCM to monitor and control the quantity of fresh air entering the unit to a minimum airflow setpoint.

An optional temperature sensor can be connected to the VCM which enables it to control a field installed fresh air preheater.

An optional CO adjusts the minimum CFM upward as the CO (reset) setpoint value for fresh air entering the unit is limited to the systems operating CFM. The following table lists the Minimum Outside Air CFM vs. Input Voltage.

sensor can be connected to the VCM to control CO2 reset. The reset function

concentrations increase. The maximum effective

Table 3. Minimum outside air setpoint w/VCM and Traq™ sensing

Unit Input Volts CFM

Casings A-Cs 0.5 - 4.5 VDC 0 - 45000

The velocity pressure transducer/solenoid assembly is illustrated below. Refer to the “Units with

Traq™ Sensor,” p. 81 section for VCM operation.

Table 4. Velocity pressure transducer/solenoid assembly

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Generic Building Automation System Module (GBAS - Optional used with non-Trane building control systems)

The Generic Building Automation System (GBAS) module allows a non-Trane building control system to communicate with the air handler unit and accepts external setpoints in the form of analog inputs for cooling, heating, supply air pressure, and a binary Input for demand limit. Refer to the "Field Installed Control Wiring" section for the input wiring to the GBAS module and the various desired setpoints with the corresponding DC voltage inputs for CV, VAV, and SZ VAV applications.

Input Devices and System Functions

The descriptions of the following basic Input Devices used within the UCM network are to acquaint the operator with their function as they interface with the various modules. Refer to the unit electrical schematic for the specific module connections.

Constant Volume (CV) and Variable Air Volume (VAV) Units

Chilled Water Valve Control

The 0 to 10 VDC output from the heat module doubles as the chilled water controller. The unit has isolating relays to switch between heat and cool.

Supply Air Temperature Sensor

An analog input device used with CV and VAV applications that monitors the supply air temperature for: supply air temperature control (VAV), supply air temperature reset (VAV), supply air temperature low limiting (CV), supply air tempering (CV/VAV). It is mounted in the supply air discharge section of the unit and is connected to the RTM.

General Information

Return Air Temperature Sensor

An analog input device used with a return humidity sensor on CV and VAV applications when the comparative enthalpy option is ordered. It monitors the return air temperature and compares it to the outdoor temperature to establish which temperature is best suited to maintain the cooling requirements. It is mounted in the return air section and is connected to the ECEM.

Filter Switch

A binary input device used on CV and VAV applications that measures the pressure differential across the unit filters. It is mounted in the filter section and is connected to the RTM. A diagnostic SERVICE signal is sent to the remote panel if the pressure differential across the filters is at least 0.5" w.c. The contacts will automatically open when the pressure differential across the filters decrease to 0.4" w.c. The switch differential can be field adjusted between 0.17" w.c. to 5.0" w.c. ± 0.05" w.c.

Supply and Exhaust Airflow Proving Switches

Supply Airflow Proving Switch is a binary input device used on CV and VAV applications to signal the RTM when the supply fan is operating. It is located in the supply fan section of the unit and is connected to the RTM. During a request for fan operation, if the differential switch is detected to be open for 40 consecutive seconds; heat operation is turned "Off", the request for supply fan operation is turned "Off" and locked out, exhaust dampers (if equipped) are "closed", economizer dampers (if equipped) are "closed", and a manual reset diagnostic is initiated.

Exhaust Airflow Proving Switch is a binary input device used on all air handler units equipped with an exhaust fan. It is located in the exhaust fan section of the unit and is connected to the RTM. During a request for fan operation, if the differential switch is detected to be open for 40 consecutive seconds, the economizer is closed to the minimum position setpoint, the request for exhaust fan operation is turned "Off" and locked out, and a manual reset diagnostic is initiated. The fan failure lockout can be reset at the Human Interface located in the unit control panel, by Tracer, or by cycling the control power to the RTM Off/On).

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General Information

Supply and Exhaust Fan Circuit Breakers

The supply fan and exhaust fan motors are protected by circuit breakers. They will trip and interrupt the power supply to the motors if the current exceeds the breaker's "must trip" value. The rooftop module (RTM) will shut all system functions "Off" when an open fan proving switch is detected.

Outdoor Air Humidity Sensor

An analog input device used on CV and VAV applications with 100% economizer. It monitors the outdoor humidity levels for economizer operation. It is mounted in the fresh air intake section and is connected to the RTM.

Return Air Humidity Sensor

An analog input device used on CV and VAV applications with the comparative enthalpy option. It monitors the return air humidity level and compares it to the outdoor humidity level to establish which conditions are best suited to maintain the cooling requirements. It is mounted in the return air section and is connected to the ECEM.

Space Humidity Sensor

Analog input device used on CV and VAV applications with modulating dehumidification option and/or humidification field installed option. It is used to monitor the humidity level in the space and compared to dehumidification and humidification setpoints to maintain space humidity requirements. It is field mounted in the space and connected to the RTM.

Status/Annunciator Output

An internal function within the RTM module on CV and VAV applications that provides:

1. diagnostic and mode status signals to the remote panel (LEDs) and to the Human Interface

2. control of the binary Alarm output on the RTM

3. control of the binary outputs on the GBAS module to inform the customer of the operational status and/or diagnostic conditions

Table 5. Transducer voltage output vs. pressure input w/ multiple sensors

Space Pressure Transducer

An analog input device used on CV and VAV applications with the Statitrac option. It modulates the exhaust dampers to keep the space pressure within the building to a customer designated controlband. It is mounted in the filter section just above the exhaust damper actuator and is

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General Information

connected to the ECEM. Field supplied pneumatic tubing must be connected between the space being controlled and the transducer assembly.

Morning Warm-Up—Zone Heat

When a system changes from an unoccupied to an occupied mode, or switches from STOPPED to AUTO, or power is applied to a unit with the MWU option, the heater in the unit or external heat will be brought on if the space temperature is below the MWU setpoint. The heat will remain on until the temperature reaches the MWU setpoint. If the unit is VAV, then the VAV box/unocc relay will continue to stay in the unoccupied position and the VFD output will stay at 100% during the MWU mode. When the MWU setpoint is reached and the heat mode is terminated, then the VAV box/unocc relay will switch to the occupied mode and the VFD output will be controlled by the duct static pressure. During Full Capacity MWU the economizer damper is held closed for as long as it takes to reach setpoint. During Cycling Capacity MWU the economizer damper is allowed to go to minimum position after one hour of operation if setpoint has not been reached.

Supply Air Temperature Low Limit

Uses the supply air temperature sensor input to modulate the economizer damper to minimum position in the event the supply air temperature falls below the occupied heating setpoint temperature.

Freezestat - Heating

A binary input device used on CV and VAV units with Hydronic Heat. It is mounted in the heat section and connected to the Heat Module. If the temperature of the air entering the heating coil falls to 40 F, the normally open contacts on the freezestat closes signalling the Heat Module and the Rooftop Module (RTM) to:

1. drive the Hydronic Heat Actuator to the full open position

2. turn the supply fan "Off"

3. closes the outside air damper

4. turns "On" the SERVICE light at the Remote Panel

5. initiates a "Freezestat" diagnostic to the Human Interface

Freezestat - Cooling

A binary input device used on CV and VAV units with Chilled Water. The freezestat is mounted on the upstream side of the cooling coil. If the temperature of the air entering the cooling coil falls to 40 F, the normally closed contacts on the freezestat open signalling the Rooftop Module (RTM) to:

1. drive the Chilled Water Actuator to the full open position

2. turn the supply fan "Off"

3. closes the outside air damper

4. turns "On" the SERVICE light at the Remote Panel

5. initiates a "Freezestat" diagnostic to the Human Interface

Chilled Water Valve Control

The 0 to 10 VDC output from the heat module doubles as the chilled water controller. The unit has isolating relays to switch between heat and cool.

Constant Volume (CV) Units

Zone Temperature—Cooling

Relies on input from a sensor located directly in the space, while a system is in the occupied "Cooling" mode. It modulates the economizer (if equipped) and/or stages the mechanical cooling "On and Off" as required to maintain the zone temperature to within the cooling setpoint deadband.

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General Information

Zone Temperature—Heating

Relies on input from a sensor located directly in the space, while a system is in the occupied "Heating" mode or an unoccupied period, to stage the heat "on and off" or to modulate the heating valve (hydronic heat only) as required to maintain the zone temperature to within the heating setpoint deadband. The supply fan will be requested to operate any time there is a requested for heat. On gas heat units, the fan will continue to run for 60 seconds after the furnace is turned off.

Supply Air Tempering

On CV units equipped with staged heat, if the supply air temperature falls 10 F below the occupied heating setpoint temperature while the heater is "Off", the first stage of heat will be turned "On". The heater is turned "Off" when the supply air temperature reaches 10º F above the occupied heating setpoint temperature.

Variable Air Volume (VAV) Units

Occupied Heating—Supply Air Temperature

When a VAV unit is equipped with "Modulating Heat", and the system is in an occupied mode, and the field supplied changeover relay contacts have closed, the supply air temperature will be controlled to the customer specified supply air heating setpoint. It will remain in the heating status until the changeover relay contacts are opened.

Occupied Cooling—Supply Air Temperature

When a VAV unit is in the occupied mode, the supply air temperature will be controlled to the customer specified supply air cooling setpoint by modulating the economizer and/or staging the mechanical cooling "On and Off" as required. The changeover relay contacts must be open on units with "Modulating Heat" for the cooling to operate.

Daytime Warm-up

On VAV units equipped with heat, if the zone temperature falls below the daytime warm-up initiate temperature during the occupied mode, the system will switch to full airflow. During this mode, the VAV box/unocc relay will be energized (this is to signal the VAV boxes to go to 100%). After the VAV box max stroke time has elapsed (factory set at 6 minutes), the VFD output will be set to 100%. The airflow will be at 100% and the heat will be turned on to control to the occupied heating setpoint. When the zone temperature reaches the daytime warm-up termination setpoint, the heat will be turned off, the relay will be de-energized, releasing the VAV boxes, the VFD output will go back to duct static pressure control and the unit will return to discharge air control. If the occ zone heating setpoint is less than the DWU terminate setpoint, the heat will turn off when the occ zone heat setpoint is reached, but it will stay in DWU mode and cycle the heat to maintain setpoint.

Unoccupied Heating—Zone Temperature

When a VAV unit is equipped with gas, electric, or hydronic heat and is in the unoccupied mode, the zone temperature will be controlled to within the customer specified setpoint deadband. During an unoccupied mode for a VAV unit, the VAV box/unocc relay will be in the unoccupied position and the VFD output will be at 100%. This means that if there is a call for heat (or cool) and the supply fan comes on, it will be at full airflow and the VAV boxes in the space will need to be 100% open as signaled by the VAV box/unocc relay.Supply Air Tempering

On VAV units equipped with "Modulating Heat", if the supply air temperature falls 10 supply air temperature setpoint, the hydronic heat valve will modulate to maintain the supply air temperature to within the low end of the setpoint deadband.

F below the

Supply Duct Static Pressure Control (Occupied)

The RTM relies on input from the duct pressure transducer when a unit is equipped with a Variable Frequency Drive to position the supply fan speed to maintain the supply duct static pressure to within the static pressure setpoint deadband. Refer to Figure 2, p. 17.

16 RT-SVX28E-EN

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Figure 2. Transducer voltage output vs. pressure input with multiple sensors

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

-0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Pressure (inches w.c.)

Volts

Single Zone Variable Air Volume (SZVAV) Only

The IntelliPak controls platform will support Single Zone VAV as an optional unit control type in order to meet ASHRAE 90.1. The basic control will be a hybrid VAV/CV configured unit that provides discharge temperature control to a varying discharge air temperature target setpoint based on the space temperature and/or humidity conditions. Concurrently, the unit will control and optimize the supply fan speed to maintain the zone temperature to a zone temperature setpoint.

General Information

Supply Fan Output Control

Units configured for Single Zone VAV control will utilize the same supply fan output control scheme as on traditional VAV units except the VFD signal will be based on zone heating and cooling demand instead of the supply air pressure.

VFD Control

Single Zone VAV units will be equipped with a VFD-controlled supply fan which will be controlled via a 0-10VDC signal from the Rooftop Module (RTM). With the RTM supply fan output energized and the RTM VFD output at 0VDC, the fan speed output is 37% (22Hz) from the VFD by default; and at 10VDC the fan speed output is 100% (60Hz). The control scales the 0-10VDC VFD output from the RTM linearly to control between the 37-100% range. The VFD will modulate the supply fan motor speed, accelerating or decelerating as required to maintain the zone temperature to the zone temperature setpoint. When subjected to high ambient return conditions the VFD will reduce its output frequency to maintain operation. Bypass control is offered to provide full nominal airflow in the event of drive failure.

Ventilation Control

Units configured for Single Zone VAV control will require special handling of the OA Damper Minimum Position control in order to compensate for the non-linearity of airflow associated with the variable supply fan speed and damper combinations. Units configured for TRAQ with or without DCV will operate identically to traditional units with no control changes.

RT-SVX28E-EN 17

Space Pressure Control

For units configured with Space Pressure Control with or without Statitrac, the new schemes implemented for economizer minimum position handling require changes to the existing Space Pressure Control scheme in order to prevent over/under pressurization. The overall scheme will remain very similar to VAV units with Space Pressure Control with the exception of the dynamic Exhaust Enable Setpoint.

For SZVAV an Exhaust Enable Setpoint must be selected during the 100% Fan Speed Command. Once selected, the difference between the Exhaust Enable Setpoint and Design OA Damper

Page 18

General Information

Minimum Position at 100% Fan Speed Command will be calculated. The difference calculated will be used as an offset and added to the Active Building Design OA Minimum Position Target in order to calculate the dynamic Exhaust Enable Target, which will be used throughout the Supply Fan Speed/OA Damper Position range.

The Exhaust Enable Target could be above or below the Active Building Design OA Minimum Position Target Setpoint, based on the Active Exhaust Enable Setpoint being set above or below the Building Design Minimum Position at 100% Fan Speed Command. Note that an Exhaust Enable Setpoint of 0% will result in the same effect on Exhaust Fan control as on VAV applications with and without Statitrac.

Occupied Cooling Operation

For normal cooling operation, cooling capacity will be staged or modulated in order to meet the calculated discharge air target setpoint. If the current active cooling capacity is controlling the discharge air within the deadband, no additional cooling capacity change will be requested. As the Discharge Air Temperature rises above the deadband, the algorithm will request additional capacity as required (additional compressors or economizer). As the Discharge Air Temperature falls below the deadband, the algorithm will request a reduction in active capacity.

Default Economizer Operation

By default, the unit will be setup to optimize the minimum supply fan speed capability during Economizer Only operation. If the economizer is able to meet the demand alone, due to desirable ambient conditions, the supply fan speed will be allowed to increase above the minimum prior to utilizing mechanical cooling if discharge air setpoint falls below the discharge air Lower Limit (Cooling) setpoint.

Unoccupied Mode

In Unoccupied mode the unit will utilize setback setpoints, 0% Minimum OA Damper position, and Auto Fan Mode operation as on normal CV units. The Supply Fan speed, and cooling and modulating types of heat, will be controlled to the discharge air target setpoint as is done during occupied periods. The Supply fan speed during staged heat control will be forced to 100% as on normal CV units.

Occupied Heating Operation

Occupied heating operation has two separate control sequences; staged and modulated. All staged heating types will drive the supply fan to maximum flow and stage heating to control to the Zone Heating Setpoint. For units with Hydronic and Gas heat, modulated SZVAV Heating. On an initial call for heating, the supply fan will drive to the minimum heating airflow. On an additional call for heating, the heat will control in order to meet the calculated discharge air target setpoint. As the load in the zone continues to request heat operation, the supply fan will ramp-up while the control maintains the heating discharge air temperature. Heating can be configured for either the energy saving SZVAV Heating solution as described above, or the traditional, less efficient CV Heating solution.

Compressor (DX) Cooling

Compressor control and protection schemes will function identical to that of a traditional unit. Normal compressor proving and disable input monitoring will remain in effect as well as normal 3-minute minimum on, off, and inter-stage timers. Also, all existing head pressure control schemes will be in effect.

Cooling Sequence

If the control determines that there is a need for active cooling capacity in order to meet the calculated discharge air target setpoint, once supply fan proving has been made, the unit will begin to stage compressors accordingly. Note that the compressor staging order will be based on unit configuration and compressor lead/lag status.

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Once the discharge air target setpoint calculation has reached the Minimum Setpoint and compressors are being utilized to meet the demand, as the discharge air target setpoint value continues to calculate lower the algorithm will begin to ramp the supply fan speed up toward 100%. Note that the supply fan speed will remain at the compressor stage’s associated minimum value (as described below) until the discharge air target setpoint value is calculated below the discharge air temperature Minimum Setpoint (limited discharge air target setpoint).

As the cooling load in the zone decreases the zone cooling algorithm will reduce the speed of the fan down to minimum per compressor stage and control the compressors accordingly. As the compressors begin to de-energize, the supply fan speed will fall back to the Cooling Stage’s associated minimum fan speed, but not below. As the load in the zone continues to drop, cooling capacity will be reduced in order to maintain the discharge air within the ± ½ discharge air target deadband.

Space Temperature Averaging

Space temperature averaging for Constant Volume applications is accomplished by wiring a number of remote sensors in a series/parallel circuit.

The fewest number of sensors required to accomplish space temperature averaging is four. The Space Temperature Averaging with Multiple Sensors figure illustrates a single sensor circuit (Single Zone), four sensors wired in a series/parallel circuit (Four Zone), nine sensors wired in a series/parallel circuit (Nine Zone). Any number squared, is the number of remote sensors required.

Wiring termination will depend on the type of remote panel or control configuration for the system. Refer to the wiring diagrams that shipped with the unit.

General Information

Table 6. Space temperature averaging with multiple sensors

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General Information

Return/

Exhaust

Fan

Fresh Air Dampers

Supply Fan

Heating Section

Exhaust Damper

Hood

Variable

Frequency

Drive (VFD)

Filter Section

Chilled Water Coil

Fresh Air Dampers

Return Air Dampers

Flue Vent

Access

Variable

Frquency

Drive (VFD)

Hot Water/Steam

Hydronic Connection

valves and actuator

Outside Air

Static Kit and

sensors

Baysens set

Controls

Table 7. Unit component layout and "ship with" locations

Unit Control Modules

Unit control modules are microelectronic circuit boards designed to perform specific unit functions. These modules, through proportional/integral control algorithms, provide the best possible comfort level for the customer. They are mounted in the control panel and are factory wired to their respective internal components. They receive and interpret information from other unit modules, sensors, remote panels, and customer binary contacts to satisfy the applicable request for economizing, mechanical cooling, heating, and ventilation. Figure 3, p. 21 illustrates the typical location of each designated module.

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Figure 3. Control module locations

BCI

General Information

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Dimensional Data

Blank Section

Cool

Coil

(F)

Fltr

(F)

Sup

Mtr

Sup VFD

Fltr (R)

Cool Coil

(R)

Heat

(L&R)

OptionStd

As Req. As Req.StdStd

Std

Rtn Mtr

Rtn

VFD

As Req.

Std

ER Fltr

(L&R) (F)

Std

ER Fltr

(L&R) (R)

Std

Final Filter

Fnl

Fltr (F)

As Req.

Fnl

Fltr (R)

As Req.

Filters

VFD

Heat

VFD

Ctrl Box

(L&R)

Std

Exhaust

Air

Exh

AH R

AH L

C Box

Unit Clearance

Figure 4. Minimum required clearance

(i) Unit drawing is representative only and may not accurately depict all models.

Table 8. Minimum required clearance

Door Location Availability A,B,C

Exhaust Motor Std 2' 2" * * * * *

Exhaust VFD As Req. * 2' 2" * * * *

Filter (Front) Std2' 8"*****

Filter (Rear) Option * * * * 2’ 2" *

Cooling Coil (Front) Std 2' 2" * * * * *

Cooling Coil (Rear) Std 2' 8" * * * * *

or Cooling Coil (Rear)Option******

Supply Motor Std2' 8"*****

Supply VFD As Req. * * 2' 2" * * *

Heat (Left & Right) As Req. * * * 2' 2" * *

Final Filter (Front) As Req. * * * * * 2' 2"

Final Filter (Rear) As Req. * * * * * 2' 2"

Control Box (L & R)Std3' 2"*****

Minimum Required Clearance (Ft.)

AH_L AH_R Exh

8’ 8’ 8’ 6’

(i)

Fresh

Unit Option Selection (Door Swing Ft. and In.)

Standard VFD Heat

Return/ Exhaust Supply

Control

Box

Electric/

Water/

Steam

Hot

Two-side

Access Final Filter

22 RT-SVX28E-EN

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Figure 5. Multiple units placement

Outdoor

Air Intake

Outdoor

Air Intake

Exhaust Air

Outdoor

Air Intake

Outdoor

Air Intake

Exhaust Air

Dimensional Data

Important: Stagger units to minimize span deflection which deters sound transmission and to

maximize proper diffusion of the exhaust air before it reaches the adjacent unit fresh air intake.

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Dimensional Data

1-1/4 NPT. DRAIN 2X TYP. LEFT & RIGHT SIDES OF UNIT

Detail A

Unit Dimensions

Figure 6. Unit top/front view

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Table 9. Unit dimensions (In.)

ONE-PIECE Dimensions

Lifting Lug Locations

Unit Dimensions Air Handler Side Unit Width

Blank

Casing

A, B, C

Section A B C1C2C3C4 M N

None 334 2/16 159 15/16 66 252 14/16 n/a n/a 139 13/16 143 8/16

4Ft 382 5/16 159 15/16 66 252 14/16 368 6/16 n/a 139 13/16 143 8/16

8Ft 430 9/16 159 15/16 66 252 14/16 416 10/16 n/a 139 13/16 143 8/16

Unit Height

Return

Fan

Exhaust

Fan

Casing O P J K

103 12/16 97 9/16 29 3/16 17

A, B, C

103 12/16 97 9/16 29 3/16 17

Table 10. Downflow/horizontal airflow configuration dimensions (in.)

Dimensional Data

Casing Gas Heat

No Gas None 14 13/16 8 14/16 48 3/16 121 15/16 14 13/16 42 14/16 48 3/16 53 14/16

No Gas 4Ft 14 13/16 8 14/16 48 3/16 121 15/16 14 13/16 42 14/16 48 3/16 53 14/16

A, B, C

No Gas 8Ft 14 13/16 8 14/16 48 3/16 121 15/16 14 13/16 42 14/16 48 3/16 53 14/16

Gas None 14 13/16 8 14/16 48 3/16 121 15/16 14 13/16 42 14/16 48 3/16 53 14/16

Gas 8Ft 14 13/16 8 14/16 48 3/16 121 15/16 14 13/16 42 14/16 48 3/16 53 14/16

Casing Gas Heat

No Gas None 256 1/16 13 47 14/16 102 8/16

No Gas 4Ft 304 4/16 13 47 14/16 102 8/16

A, B, C

No Gas 8Ft 352 8/16 13 47 14/16 102 8/16

Gas None 256 1/16 13 47 14/16 102 8/16

Gas 8Ft 352 8/16 13 47 14/16 102 8/16

Casing Gas Heat

No Gas None 9 5/16 10 10/16 54 12/16 84 15/16 6 5/16 8 3/16 35 3/16 127 2/16

No Gas 4Ft 9 5/16 10 10/16 54 12/16 84 15/16 6 5/16 8 3/16 35 3/16 127 2/16

A, B, C

No Gas 8Ft 9 5/16 10 10/16 54 12/16 84 15/16 6 5/16 8 3/16 35 3/16 127 2/16

Gas None 9 5/16 10 10/16 54 12/16 84 15/16 6 5/16 8 3/16 35 3/16 127 2/16

Gas 8Ft 9 5/16 10 10/16 54 12/16 84 15/16 6 5/16 8 3/16 35 3/16 127 2/16

DOWNFLOW Opening Dimensions

Return Opening—with or

without Exhaust Fan

Return Opening—with Return Fan

Blank

SectionX1Y1W1L1X1Y1W1L1

DOWNFLOW Opening Dimensions

Supply Opening

Blank

Section X2 Y2 W2 L2

HORIZONTAL Opening Dimensions

Return Side Opening Return End Opening

Blank

SectionX3Y3W3H1X1Y3H3H1

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Page 26

Dimensional Data

3 4

1 4

3 4

Ø3

5 8

Ø1

7 8

Marine lights

customer supplied power service entrance

Unit power

External customer connection points

Outside edge of base rail

5 8

Ø1

Table 10. Downflow/horizontal airflow configuration dimensions (in.)

HORIZONTAL Opening Dimensions

Supply Opening

Casing Gas Heat

No Gas None 254 12/16 10 10/16 54 12/16 84 15/16

No Gas 4Ft 302 15/16 10 10/16 54 12/16 84 15/16

A, B, C

No Gas 8Ft 351 3/16 10 10/16 54 12/16 84 15/16

Gas None 254 12/16 10 10/16 54 12/16 66 11/16

Gas 8Ft 351 3/16 10 10/16 54 12/16 84 15/16

Blank

Section X4 Y4 W4 H2

Figure 7. Electrical entry details/bottom view

26 RT-SVX28E-EN

Page 27

Figure 8. Chilled water piping locations

Dimensional Data

Figure 9. Piping enclosure

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Page 28

Pre-Installation

General Unit Requirements

The checklist below is a summary of the steps required to successfully install a commercial rooftop air handler. This checklist is intended to acquaint the installing personnel with what is required in the installation process. It does not replace the detailed instructions called out in the applicable sections of this manual.

• Check the unit for shipping damage and material shortage; file a freight claim and notify Trane office.

• Verify that the installation location of the unit will provide the required clearance for proper operation.

• Assemble and install the roof curb. Refer to the current edition of the roof curb installer’s guide.

• Install and connect condensate drain lines to each cooling coil drain connection.

Figure 10. Sealed ductwork

• Fabricate and install ductwork; secure ductwork to curb. Seal the corners of duct adapters as shown in Figure 10. Ducting attached to the unit should be self supporting. Do not use the unit to support the weight of the ducting

• Install pitch pocket for power supply through building roof. (If applicable)

28 RT-SVX28E-EN

Page 29

Rigging the Unit

• Set the unit onto the curb; check for levelness.

• Ensure unit-to-curb seal is tight and without buckles or cracks.

• Remove the shipping hold-down bolts and shipping channels from the supply and exhaust fans with spring isolators.

• Check all supply and exhaust fan spring isolators for proper adjustment.

Main Electrical Power Requirements

• Verify that the power supply complies with the unit nameplate specifications.

• Inspect all control panel components; tighten any loose connections.

• Connect properly sized and protected power supply wiring to a field-supplied/installed disconnect and unit

• Properly ground the unit.

• All field-installed wiring must comply with NEC and applicable local codes.

Field Installed Control Wiring

• Complete the field wiring connections for the constant volume controls as applicable. Refer to "Field Installed Control Wiring" for guidelines.

• Complete the field wiring connections for the variable air volume controls as applicable. Refer to "Field Installed Control Wiring" for guidelines.

Note: All field-installed wiring must comply with NEC and applicable local codes.

Pre-Installation

Requirements for Electric Heat Units

• Verify that the power supply complies with the electric heater specifications on the unit and heater nameplate.

• Inspect the heater junction box and control panel; tighten any loose connections.

• Check electric heat circuits for continuity.

Requirement for Gas Heat

• Gas supply line properly sized and connected to the unit gas train.

• All gas piping joints properly sealed.

• Drip leg Installed in the gas piping near the unit.

• Gas piping leak checked with a soap solution. If piping connections to the unit are complete, do not pressurize piping in excess of 0.50 psig or 14 inches w.c. to prevent component failure.

• Main supply gas pressure adequate.

• Flue Tubes clear of any obstructions.

• Factory-supplied flue assembly installed on the unit.

• Connect the 3/4" CPVC furnace drain stubout to a proper condensate drain.

Requirements for Hot Water Heat

• Route properly sized water piping through the base of the unit into the heating section.

• Install the factory-supplied, 3-way modulating valve.

• Complete the valve actuator wiring.

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Page 30

Pre-Installation

Base rail

Cleanout Plug

1 4

Inch NPT

Female Connection

Field supplied condensate piping

5.5"

2.5"

Requirements for Steam Heat

• Route properly sized steam piping through the base of the unit into the heating section.

• Install the factory-supplied, 2-way modulating valve

• Complete the valve actuator wiring.

• Install 1/2", 15-degree swing-check vacuum breaker(s) at the top of each coil section. Vent breaker(s) to the atmosphere or merge with return main at discharge side of steam trap.

• Position the steam trap discharge at least 12" below the outlet connection on the coil.

• Use float and thermostatic traps in the system, as required by the application.

Requirements for Chilled Water Cooling

• Install and connect condensate drain lines to each cooling coil drain connection.

• Route properly sized water piping through the back of the unit.

• Install external piping enclosure.

• Install the factory-supplied, 3-way modulating valve.

• Complete the valve actuator wiring.

O/A Pressure Sensor and Tubing Installation (all units with Statitrac)

• O/A pressure sensor mounted to the roof bracket.

• Factory supplied pneumatic tubing installed between the O/A pressure sensor and the connector on the vertical support.

• Field supplied pneumatic tubing connected to the proper fitting on the space pressure transducer located in the filter section, and the other end routed to a suitable sensing location within the controlled space.

Condensate Drain Connections

Each unit provides two 1-1/4" cooling coil condensate drain connections on each side of the unit.

Due to the size of these units, all condensate drain connections must be connected to the cooling coil drain connections. Refer to Detail A in Figure 6, p. 24 for the location of these drain connections.

A condensate trap must be installed due to the drain connection being on the "negative pressure" side of the fan. Install the P-Traps at the unit using the guidelines in Figure 11.

Figure 11. Condensate trap installation

30 RT-SVX28E-EN

Page 31

Figure 12. Trap installation inside external piping enclosure

Pre-Installation

Pitch the drain lines at least 1/2 inch for every 10 feet of horizontal run to assure proper condensate flow. Do not allow the horizontal run to sag causing a possible double-trap condition which could result in condensate backup due to "air lock".

For units with an external piping enclosure, the condensate trap must be run through the external piping enclosure on the rear side of the unit. Use Figure 12 as a guideline to install a P-Trap at the back of the unit when an external piping enclosure is mounted around the condensate drain connection.

Units with Gas Furnace

Units equipped with a gas furnace have a 3/4" CPVC drain connection stubbed out through the vertical support in the gas heat section. It is extremely important that the condensate be piped to a proper drain. Refer to the appropriate illustration in Figure 6, p. 24 for the location of the drain connection.

Note: Units equipped with an optional modulating gas furnace will likely operate in a condensing

mode part of the time.

Ensure that all condensate drain line installations comply with applicable building and waste disposal codes.

Removing Supply and Exhaust Fan Shipping Channels

Each supply fan assembly and exhaust fan assembly is equipped with spring isolators. Shipping channels are installed beneath each fan assembly and must be removed. To locate and remove these channels, refer to Figure 13, p. 32 and use the following procedures.

Spring Isolators

Spring isolators for the supply and/or exhaust fan are shipped with the isolator adjusting bolt backed out. Field adjustment is required for proper operation. Figure 13, p. 32 shows isolator locations. To adjust the spring isolators use the following procedure.

1. Remove and discard the shipping tie down bolts but leave the shipping channels in place during the adjustment procedure. See Figure 13, p. 32.

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Page 32

Pre-Installation

2. Tighten the leveling bolt on each isolator until the fan assembly is approximately 1/4" above each sh ipp ing chann el.

3. Secure the lock nut on each isolator.

4. Remove the shipping channels and discard.

Figure 13. Removing fan assembly shipping hardware

O/A Sensor and Tubing Installation

An Outside Air Pressure Sensor is shipped with all units designed to operate on variable air volume applications or constant volume units with 100% modulating exhaust w/Stratitrac.

On VAV systems, a duct pressure transducer and the outside air sensor is used to control the discharge duct static pressure to within a customer-specified parameter.

On CV & VAV units equipped with 100% modulating exhaust w/Stratitrac, a space pressure transducer and the outside air sensor is used to control the exhaust fan and dampers to relieve static pressure, to within a customer-specified parameter, within the controlled space. Refer to

Figure 14, p. 33 and the following steps to install the sensor and the pneumatic tubing.

1. Remove the O/A pressure sensor kit located inside the "ship with" item container. The kit contains the following items:

a. O/A static pressure sensor with slotted mounting bracket

b. 50 ft. 0.188 in tubing

c. Mounting hardware

2. Remove the two roof cap screws and install the provided L mounting bracket as shown in the figure.

3. Place the sensor mounting slotted bracket to the L mounting bracket with the slot located to the top.

4. Install the sensor vertically to the slotted bracket and secure it with provided bolt and nut.

5. Connect one end of factory provided tubing to the top port of sensor and pass it through the two slots in the mount and the other end to the port in the base.

6. Secure the tubing with the mounting hardware located in the ship with item container.

32 RT-SVX28E-EN

Page 33

Units with Statitrac

Sensor

Sensor mounting slotted bracket

0.188in OD tubing

L bracket

Sensor mounting screws

1. Open the filter access door, and locate the DSP control devices illustrated in Figure 15. There

Figure 14. Outside air sensing kit

Pre-Installation

are three tube connectors mounted on the left of the solenoid and transducers. Connect one end of the field provided1/4" (length 50-100 ft.) or 3/8" (length greater than 100 ft.) O.D. pneumatic tubing for the space pressurization control to the bottom fitting. Route the opposite end of the tubing to a suitable location inside the building. This location should be the largest open area that will not be affected by sudden static pressure changes.

Figure 15. DSP control device

RT-SVX28E-EN 33

Page 34

Installation

Unit Weights

Table 11. Approximate operating weights (lbs.)

Nominal Tons Unit (Minimum)

A 8580 1066

B 8782 1066

C 8910 1066

Notes:

1. Weights shown include the following features: standard coils, 0-25% Fresh Air, throwaway filters, low cfm supply fan,

minimum motor sizes, constant volume, 460 XL, No heat.

2. Weights shown represent approximate operating weights and have a + 5% accuracy. To calculate weight for a specific

unit configuration, utilize TOPSS or contact the local Trane sales representative. ACTUAL WEIGHTS ARE STAMPED ON THE UNIT NAMEPLATE.

Roof Curb

(Minimum)

Table 12. Component weights (lbs.)

AB C

Size Wt (lbs.) Size Wt (lbs.) Size Wt (lbs.)

Supply Fan Assembly

Supply Fan & FanBoard Assy. 25" 1226 32" 1419 36" 1530

Belt Guard 116 116 116

Supply VFD (50 HP and below) 233 233 233

Supply VFD (60 thru 75 HP) 284 284 284

Supply-Exh Fan Motor - 15 HP 181 181 181

Supply-Exh Fan Motor - 20 HP 206 206 206

Supply-Exh Fan Motor - 25 HP 358 358 358

Supply-Exh Fan Motor - 30 HP 413 413 413

Supply-Exh Fan Motor - 40 HP 495 495 495

Supply-Exh Fan Motor - 50 HP 604 604 604

Supply-Exh Fan Motor - 60 HP - 776 776

Supply-Exh Fan Motor - 75 HP - - 879

Return/Exhaust Fan Assembly

Return Fan & Dampers 36" 2284 40" 2333 40" 2333

Exhaust Fan & Dampers - Low CFM 25" 879 25" 879 28" 963

Exhaust Fan & Dampers - Std CFM - - 28" 963 32" 1417

Belt Guard 119 119 119

Exhaust VFD (50 HP and below) 244 244 244

Exhaust VFD (60 HP) 295 295 295

Exh Fan Motor - 7.5 HP 160 160 -

Exh Fan Motor - 10 HP 181 181 181

Exh Fan Motor - 15 HP 206 206 206

Exh Fan Motor - 20 HP 206 206 206

Exh Fan Motor - 25 HP 358 358 358

Exh Fan Motor - 30 HP - 413 413

Exh Fan Motor - 40 HP - 495 495

Exh Fan Motor - 50 HP - 604 604

Exh Fan Motor - 60 HP - - 776

34 RT-SVX28E-EN

Page 35

Table 12. Component weights (lbs.) (continued)

AB C

Size Wt (lbs.) Size Wt (lbs.) Size Wt (lbs.)

Chilled Water Assy.

2 Row 5W Chilled Water Coil - 80 FPF 992 992 992

2 Row 5W Chilled Water Coil - 108 FPF 1042 1042 1042

2 Row 5W Chilled Water Coil - 144 FPF 1106 1106 1106

2 Row 5W Chilled Water Coil - 168 FPF 1148 1148 1148

4 Row W Chilled Water Coil - 80 FPF 1523 1523 1523

4 Row W Chilled Water Coil - 108 FPF 1622 1622 1622

4 Row W Chilled Water Coil - 144 FPF 1750 1750 1750

4 Row W Chilled Water Coil - 168 FPF 1835 1835 1835

6 Row WD Chilled Water Coil - 80 FPF 2046 2046 2046

6 Row WD Chilled Water Coil - 108 FPF 2195 2195 2195

6 Row WD Chilled Water Coil - 144 FPF 2387 2387 2387

6 Row WD Chilled Water Coil - 168 FPF 2515 2515 2515

8 Row WD Chilled Water Coil - 80 FPF 2643 2643 2643

8 Row WD Chilled Water Coil - 108 FPF 2842 2842 2842

8 Row WD Chilled Water Coil - 144 FPF 3098 3098 3098

8 Row WD Chilled Water Coil - 168 FPF 3268 3268 3268

External Piping Cabinet

External Piping Cabinet - Shipping 353 353 353

External Piping Cabinet - Operation 268 268 268

Gas/Electric Heat

Gas Heat Low 0.85M 690 0.85M 690 0.85M 690

Gas Heat Med 1.1M 840 1.1M 840 1.1M 840

Gas Heat High 1.8M 1150 1.8M 1150 1.8M 1150

Electric Heat 485 485 485

Hydronic Heat

Steam Heat Low 946 946 946

Steam Heat High 1014 1014 1014

Hot Water Heat Low 1080 1080 1080

Hot Water Heat High 1125 1125 1125

Filters

Filter Rack - Throwaway Filters 181 181 181

Filter Rack - Bag Filters 395 395 395

Filter Rack - Cartridge Filters 662 662 662

Final Filters - Bag Filters 392 392 392

Final Filters - Cartridge Filters w/ 2" pre-filter 607 607 607

Final Filters - Cartridge Filters w/ 4" pre-filter 638 638 638

Final Filters - High Temp. Cartridge 669 669 669

Final Filters - HEPA 1777 1777 1777

Final Filters - HEPA High Temp. 1839 1839 1839

Installation

RT-SVX28E-EN 35

Page 36

Installation

Table 12. Component weights (lbs.) (continued)

AB C

Size Wt (lbs.) Size Wt (lbs.) Size Wt (lbs.)

Fresh Air

0-25% Damper 611 611 611

Econ 759 759 759

Econ w/ Air Measure 715 715 715

Cabinet

Cabinet 5971 5971 5971

Cabinet - 4' Blank Section 846 846 846

Cabinet - 8' Blank Section 1650 1650 1650

Control Box - Main

Control Box - Main 454 454 454

Convenience Outlet 36 36 36

Table 13. Roof curb weights

Casing Blank

A, B, C

Roof Curb and Ductwork

The roof curb for air handler units consist of two main components; a "full perimeter" enclosure to support the unit air handler section and an add on substructure to support the external piping enclosure when the chilled water option is selected.

Before installing any roof curb, verify;

1. That it is the correct curb for the unit,

2. That it includes the necessary gaskets and hardware

3. That the purposed installation location provides the required clearance for proper operation.

Insure that the curb is level and square. The top surface of the curb must be true to assure an adequate curb-to-unit seal.

Step-by-step curb assembly and installation instructions ship with each Trane accessory roof curb kit. Follow the instructions carefully to assure proper fit-up when the unit is set into place.

Note: To assure proper condensate flow during operation, the unit (and curb) must be as level as

possible. The maximum slope allowable for rooftop unit applications, excluding Steam Heat Units, is 4" end-to-end and 2" side-to-side. Units with steam coils must be set level!

If the unit is elevated, a field constructed catwalk around the unit is strongly recommended to provide easy access for unit maintenance and service.

Recommendations for installing the Supply Air and Return Air ductwork joining the roof curb are included in the curb instruction booklet. Curb ductwork must be fabricated and installed by the installing contractor before the unit is set into place.

Note: For sound consideration, cut only the holes in the roof deck for the ductwork penetrations.

Do not cut out the entire roof deck within the curb perimeter.

Installed

Weight

None 1066 1334

4 Ft 1147 1415

8 Ft 1228 1497

Shipping

Weight

36 RT-SVX28E-EN

Page 37

Pitch Pocket Location

Pitch Pocket

Roof Curb 1Pc

The location of the main supply power entry is located at the bottom right-hand corner of the control panel. Figure 16 illustrates the location for the electrical entrance through the base in order to enter the control panel. If the power supply conduit penetrates the building roof beneath this opening, it is recommended that a pitch pocket be installed before the unit is placed onto the roof curb.

The center line dimensions shown in the illustration below indicates the center line of the electrical ac cess ho l e in the u nit ba se when it i s posit i oned on the curb, ±3/8 inch. The actual diameter of the hole in the roof should be at least 1/2 inch larger than the diameter of the conduit penetrating the roof. This will allow for the clearance variable between the roof curb rail and the unit base rail illustrated in Figure 16.

The pitch pocket dimensions listed are recommended to enhance the application of roofing pitch after the unit is set into place. The pitch pocket may need to be shifted as illustrated to prevent interference with the curb pedestal.

Figure 16. Pitch pocket location

Installation

Table 14. Pitch pocket dimensions (in.)

Tonnages A1 B1 B2 B3

Casings A-C 9.52 68.875 73.875 78.875

If a Trane Curb Accessory Kit is not used

If a Trane Curb Accessory Kit is not used:

1. The ductwork can be attached directly to the unit bottom, around the unit supply and return air openings. Be sure to use flexible duct connections at the unit. The customer is responsible for sealing the bottom of the external piping enclosure when the unit contains the chilled water

RT-SVX28E-EN 37

option.

2. For "built-up" curbs supplied by others, gaskets must be installed around the unit, external piping enclosure curb, and the supply and return air opening perimeters. The customer is responsible for sealing the bottom of the external piping enclosure when the unit contains the chilled water option.

3. Units that come with external piping enclosures must be mounted on a roof curb.

Page 38

Installation

Notes:

• If a "built-up" curb is provided by others, keep in mind that external piping enclosure roof curbs

must have a notch for the air handler unit base rail.

• If a "built-up" curb is provided by others, it should NOT be made of wood.

• If this is a REPLACEMENT UNIT keep in mind that the CURRENT DESIGN rooftop air handler

units with chilled water require an add-on roof curb for the external piping enclosure.

Field Converting Horizontal Ductwork from Right to the Left Side

To field convert horizontal ductwork from one side to the other, follow this procedure:

1. Remove the door and door header from the left side.

2. Remove Panel 2.

3. Remove Post and Panel 1.

4. Place door and door header removed from the left side in the empty location on the end wall.

5. Remove the horizontal duct header, footer, and side flange kits and install them at the empty left side.

6. Finally place Panel 2, Post, and Panel 1 at the empty spot on the right horizontal side to complete the field conversion.

Figure 17. Ductwork conversion

Unit Rigging and Placement

WARNING

Heavy Objects!

Do not use cables (chains or slings) except as shown. Each of the cables (chains or slings) used to lift the unit must be capable of supporting the entire weight of the unit. Lifting cables (chains or slings) may not be of the same length. Adjust as necessary for even unit lift. Other lifting arrangements may cause equipment or property-only damage. Failure to properly lift unit could result in death or serious injury. See details below.

1. To configure the unit center-of-gravity, utilize TOPPS or contact the local Trane sales office.

38 RT-SVX28E-EN

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Installation

2. Attach adequate strength lifting slings to all lifting lugs. The minimum distance between the lifting hook and the top of the unit should be 12 feet. Figure 19, p. 40, Figure 20, p. 40, and

Figure 21, p. 41 illustrate the installation of spreader bars to protect the unit and to facilitate a

uniform lift. Tab le 1, p . 10 lists typical approximate minimal unit operating weights. To determine additional component weight, see Table 2, p. 10

WARNING

Improper Unit Lift!

Test lift unit approximately 24 inches to verify proper center of gravity lift point. To avoid dropping of unit, reposition lifting point if unit is not level. Failure to properly lift unit could result in unit dropping and possibly crushing operator/technician which could result in death or serious injury and possible equipment or property-only damage.

3. Test lift the unit to ensure it is properly rigged and balanced, make any necessary rigging adjustments.

4. Lift the unit and position it over the curb and pedestal. (These units have a continuous base rail around the air handler section which matches the curb.

5. Align the base rail of the unit air handler section with the curb rail while lowering the unit onto the curb. Make sure that the gasket on the curb is not damaged while positioning the unit. (The pedestal simply supports the unit condenser section)

A cross section of the juncture between the unit and the roof curb is shown in Figure 18, p. 39.

Figure 18. Curb cross section

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Page 40

Installation

Figure 19. Typical unit rigging—air handler with two lifting lugs per side

Note: Turnbuckle or Chain Adjustment required for each lifting point.

Figure 20. Typical unit rigging—air handler with three lifting lugs per side

Note: Turnbuckle or Chain Adjustment required for each lifting point.

40 RT-SVX28E-EN

Page 41

Figure 21. Typical unit rigging—air handler with four lifting lugs per side

20 ft min

Installation

Lifting the External Piping Enclosure

Lifting Damage!

Do not attach the external piping enclosure to the unit prior to lifting the unit. Doing so could damage the air handler or piping enclosure.

1. Detach external piping enclosure from shipping skid as shown in Figure 22.

2. Attach the cables, chains or straps to lifting lugs Figure 23, p. 45.

Note: Rigging and spreader bars not furnished by Trane.

NOTICE:

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Page 42

Installation

Crate Attachment Points

Rigging and spreader bar not furnished by Trane

Figure 22. External piping enclosure crate

Gas Heat Units

All internal gas piping is factory-installed and pressure leak-tested before shipment. Once the unit is set into place, the gas supply line must be field-connected to the elbow located inside the gas heat control compartments.

WARNING

Hazardous Gases and Flammable Vapors!

Exposure to hazardous gases from fuel substances have been shown to cause cancer, birth defects or other reproductive harm. Improper installation, adjustment, alteration, service or use of this product could cause flammable mixtures or lead to excessive carbon monoxide. To avoid hazardous gases and flammable vapors follow proper installation and set up of this product and all warnings as provided in this manual. Failure to follow all instructions could result in death or serious injury.

WARNING

Hazardous Pressures!

When using dry nitrogen cylinders for pressurizing units for leak testing, always provide a pressure regulator on the cylinder to prevent excessively high unit pressures. Never pressurize unit above the maximum recommended unit test pressure as specified in applicable unit literature. Failure to properly regulate pressure could result in a violent explosion, which could result in death or serious injury or equipment or property-only-damage.

Access holes are provided on the unit as illustrated in Figure 25, p. 47 to accommodate a side or bottom pipe entry. Following the guidelines listed below will enhance both the installation and operation of the furnace.

Note: In the absence of local codes, the installation must conform with the American National

Standard Z223-1a of the National Fuel Gas Code, (latest edition).

42 RT-SVX28E-EN

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Installation

1. To assure sufficient gas pressure at the unit, use Table 15, p. 44 as a guide to determine the appropriate gas pipe size for the unit heating capacity listed on the unit nameplate.

2. If a gas line already exists, verify that it is sized large enough to handle the additional furnace capacity before connecting to it.

3. Take all branch piping from any main gas line from the top at 90 degrees or at 45 degrees to prevent moisture from being drawn in with the gas.

4. Ensure that all piping connections are adequately coated with joint sealant and properly tightened. Use a piping compound that is resistant to liquid petroleum gases.

5. Provide a drip leg near the unit.

6. Install a pressure regulator at the unit that is adequate to maintain 7" w.c. for natural gas while the furnace is operating at full capacity.

NOTICE:

Gas Valve and Gas Train Damage!

• Gas pressure in excess of 14" w.c. or 0.5 psig will damage the gas train.

• Failure to use a pressure regulating device will result in incorrect gas pressure. This can cause erratic operation due to gas pressure fluctuations as well as damage the gas valve.

• Over sizing the regulator will cause irregular pulsating flame patterns, burner rumble, potential flame outages, and possible gas valve damage.

If a single pressure regulator serves more than one air handler unit, it must be sized to ensure that the inlet gas pressure does not fall below 7" w.c. with all the furnaces operating at full capacity. The gas pressure must not exceed 14" w.c. when the furnaces are off.

7. Provide adequate support for all field installed gas piping to avoid stressing the gas train and controls.

8. Leak test the gas supply line using a soap-and-water solution or equivalent before connecting it to the gas train.

9. Check the supply pressure before connecting it to the unit to prevent possible gas valve damage and the unsafe operating conditions that will result.

Important: Do not rely on the gas train shutoff valves to isolate the unit while conducting gas

pressure/leak test. These valves are not designed to withstand pressures in excess of 14" w.c. or 0.5 psig.

Connecting the Gas Supply Line to the Furnace Gas train

Follow the steps below to complete the installation between the supply gas line and the furnace. Refer to Figure 23, p. 45, and Figure 24, p. 45 for the appropriate gas train configuration.

1. Connect the supply gas piping using a "ground-joint" type union to the furnace gas train and check for leaks.

2. Adjust the inlet supply pressure to the recommended 7" to 14" w.c. parameter for natural gas

3. Ensure that the piping is adequately supported to avoid gas train stress.

4. If the through the base gas opening is used, seal off around the pipe and the 3" water dam. If the through the base gas opening is not used, the 3" opening should be sealed shut to prevent indoor air leakage.

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Installation

Table 15. Sizing natural gas pipe mains and branches

Gas Input (Cubic Feet/Hour)*

Gas Supply

Pipe Run (ft)

10 1050 1600 3050 4800 8500 17500

20 730 1100 2100 3300 5900 12000

30 590 890 1650 2700 4700 9700

40 500 760 1450 2300 4100 8300

50 440 670 1270 2000 3600 7400

60 400 610 1150 1850 3250 6800

70 370 560 1050 1700 3000 6200

80 350 530 990 1600 2800 5800

90 320 490 930 1500 2600 5400

100 305 460 870 1400 2500 5100

125 275 410 780 1250 2200 4500

150 250 380 710 1130 2000 4100

175 225 350 650 1050 1850 3800

200 210 320 610 980 1700 3500

*Table is based on a specific gravity of 0.60. Use Tab le 1 6 for the specific gravity of the local gas supply.

Notes:

1. If more than one unit is served by the same main gas supply, consider the total gas input (cubic feet/hr.) and the total length when determining the appropriate gas pipe size.

2. Obtain the Specific Gravity and BTU/Cu.Ft. from the gas company.

3. The following example demonstrates the considerations necessary when determining the actual pipe size:

Example: A 40' pipe run is needed to connect a unit with a 850 MBH furnace to a natural gas supply having a rating of 1,000 BTU/Cu.Ft. and a specific gravity of 0.60

Cu.Ft/Hour = Furnace MBH Input Gas BTU/Cu.Ft. X Multiplier Tab le 1 6 Cu.Ft/Hour = 850 This table indicates that a 2" pipe is required.

1-1/4"

Pipe

1-1/2"

Pipe

2-1/2"

Pipe

Table 16. Specific gravity multipliers

Specific Gravity Multiplier

0.50 1.10

0.55 1.04

0.60 1.00

0.65 0.96

44 RT-SVX28E-EN

Page 45

Table 17. Gas heating capacity altitude correction factors

Altitude (Ft.)

Sea Level

To 2000

Capacity Multiplier

Note: Correction factors are per AGA Std. 221.30 - 1964, Part VI, 6.12. Local codes may supersede.

1.00 .92 .88 .84 .80 .76 .72

2001 to

2500

2501 to

3500

3501 to

4500

4501 to

5500

5501 to

6500

Figure 23. Two-Stage natural gas train

Installation

6501 to

7500

Figure 24. Modulating natural gas train

RT-SVX28E-EN 45

Page 46

Installation

Table 18. Gas heat inlet sizes

Standard Gas

Heat Input

(MBh)

850 1

1100 1 1/4

1800 1 1/2

Gas Heat Inlet

Sizes (in.)

Flue Assembly Installation

1. Locate the collapsed flue assembly in the compartment above the gas heat controls by removing the panel screws. The assembly is secured by screws up through the roof of the gas controls compartment roof.

2. Separate the pieces of the collapsed assembly.

3. Then assemble the stack as shown in

Figure 26.

4. Insert the tube on the flue assembly into the hole located in the vertical support for the heat section.

5. Butt both tube sections together and center the pipe clamp over joint.

6. Using the pre-punch hole in the flue assembly, extension, and the vertical support, install the appropriate number of mounting brackets (Refer to the installation instructions that ship with the flue assembly.)

NOTICE:

Equipment Damage!

Properly seal all penetrations in unit casing. Failure to seal penetrations from inner panel to outer panel may result in unconditioned air entering the module, and water infiltrating the insulation, resulting in equipment damage.

46 RT-SVX28E-EN

Page 47

Figure 25. Gas heat piping penetration locations

7 8

5 8

1.8M (W=16 1/8in, D=14 11/16in)

1.1M, 0.8M (W=9 15/16in, D=9 12/16in)

Horizontal gas pipe inlet Pipe type: Black pipe, sch 40

Condensate drain outlet Pipe type: cpvc

Hole at the base

Ø3

Unit end plane

Edge of mist eliminator

Top View

Side View

Installation

Table 19. Gas heat piping connection locations

Casings

A-C

Hot Water Heat Units

Hot water heating coils are factory installed inside the heater section of the unit. Once the unit is

RT-SVX28E-EN 47

set into place, the hot water piping and the factory provided three way modulating valve must be installed. The valve can be installed inside the heat section or near the unit. If the valve is installed in a remote location, use field supplied wiring to extend the control wires from the heater section to the valve. Two access holes are provided in the unit base as illustrated in Figure 26, p. 51.

Following the guidelines listed below will enhance both the installation and operation of the "wet heat" system.

Figure 27, p. 51 illustrates the recommended piping configuration for the hot water coil. Table 20 on page 50 lists the coil connection sizes.

Important: The valve actuators are not waterproof. Failure to protect the valve from moisture

Distance from Mist

Eliminator to the

Center of Flu

KCHB

1.8M 1.1M 0.8M 1.8M 1.1M 0.8M 1.8M 1.1M 0.8M

160.1 159.9 159.9 254.9 263.6 263.6 266.2 265.3 265.3 274.8

Distance of

Condensate Drain

Outlet

Distance of Horizontal

Gas Pipe Inlet

may result in the loss of heating control.

Page 48

Installation

1. Support all field-installed piping independently from the heating coil.

2. Use swing joints or flexible connectors adjacent to the heating coil. (These devices will absorb the strains of expansion and contraction).

3. All return lines and fittings must be equal to the diameter of the "outlet" connection on the hot water coil.

4. Install a "Gate" type valve in the supply branch line as close as possible to the hot water main and upstream of any other device or takeoff.

5. Install a "Gate" type valve in the return branch line as close as possible to the return main and down stream of any other device.

6. Install a strainer in the hot water supply branch as shown in Figure 27, p. 51.

7. Install the 3-way valve in an upright position, piped for valve seating against the flow. Ensure that the valve location lends itself to serviceability.

8. The Type "W" hot water coil is self-venting only when the tube water velocity exceeds 1.5 feet per second (fps). If the tube velocity is less than 1.5 feet per second, either:

a. install an automatic air vent at the top of the return header, using the tapped pipe connection

or,

b. vent the coil from the top of the return header down to the return piping. At the vent

connection, size the return piping to provide sufficient water velocity.

9. Install a "Globe" type valve in the Bypass line as shown in Figure 27, p. 51.

Steam Heat Units

Steam heating coils are factory installed inside the heater section of the unit. The coils are pitched, within the units, to provide the proper condensate flow from the coil. To maintain the designed degree of pitch for the coil, the unit must be level.

Once the unit is set into place, the steam piping and the factory provided two way modulating valve must be installed. The valve can be installed inside the heater section or near the unit. If the valve is installed in a remote location, use field supplied wiring to extend the control wires from the heater section to the valve. Two access holes are provided in the unit base as illustrated in

Figure 26, p. 51.

Following the guidelines listed below will enhance both the installation and operation of the "wet heat" system.

Figure 28, p. 52 illustrates the recommended piping configurations for the steam coil. Table 20, p. 50 lists the coil connection sizes.

Important: The valve actuators are not waterproof. Failure to protect the valve from moisture

1. Support all field-installed piping independently from the heating coil.

2. Use swing joints or flexible connectors adjacent to the heating coil. (These devices will absorb the strains of expansion and contraction.)

3. Install the 2-way valve in an upright position. Ensure that the valve's location lends itself to serviceability.

4. Pitch the supply and return steam piping downward 1" per 10' of run in the direction of flow.

5. All return lines and fittings must be equal to the diameter of the "outlet" connection on the steam coil(s). If the steam trap connection is smaller that the coil "outlet" diameter, reduce the pipe size between the strainer and the steam trap connections only.

6. Install a 1/2" 15 degree swing-check vacuum breaker at the top of the return coil header using the tapped pipe connection. Position the vacuum breaker as close to the coil as possible.

may result in the loss of heating control.

48 RT-SVX28E-EN

Page 49

Installation

Note: Vacuum breakers should have extended lines from the vent ports to the atmosphere or

connect each vent line to the return pipe on the discharge side of the steam traps.

7. Install a "Gate" type valve in the supply branch line as close as possible to the steam main and upstream of any other device.

8. Install a "Gate" type valve in the return branch line as close as possible to the condensate return main and downstream of any other device.

9. Install a strainer as close as possible to the inlet of the control valve and steam trap(s).

10. Steam trap selection should be based on the maximum possible condensate flow and the recommended load factors.

11. Install a Float-and-Thermostatic (FT) type trap to maintain proper flow. They provide gravity drains and continuous discharge operation. FT type traps are required if the system includes either;

a. an atmospheric pressure/gravity condensate return;

or,

b. a potentially low pressure steam supply.

12. Position the outlet or discharge port of the steam trap at least 12" below the outlet connection on the coil(s). This will provide adequate hydrostatic head pressure to overcome the trap losses and assure complete condensate removal.

The two steam coils are stacked together and must be piped in a parallel arrangement. The steps listed below should be used in addition to the previous steps. Figure 28, p. 52 illustrates the recommended piping configuration for the steam coils.

13. Install a strainer in each return line before the steam trap.

14. Trap each steam coil separately as described in steps 10 and 11 to prevent condensate backup in one or both coils.

15. In order to prevent condensate backup in the piping header supplying both coil sections, a drain must be installed utilizing a strainer and a steam trap as illustrated in Figure 28, p. 52.

General Coil Piping and Connection Recommendations

Important: Proper installation, piping, and trapping is necessary to ensure satisfactory coil

operation and to prevent operational damage:

• Support all piping independently of the coils.

• Provide swing joints or flexible fittings on all connections that are adjacent to heating coils to absorb thermal expansion and contraction strains.

• Install factory supplied control valves (valves ship separately).

Note: The contractor is responsible for supplying the installation hardware.

NOTICE:

Coil Header Damage!

Use a backup wrench when attaching piping to coils with copper headers to prevent damage to the coil header. Do not use brass connectors because they distort easily and could cause connection leaks.

• When attaching the piping to the coil header, make the connection only tight enough to prevent leaks. Maximum recommended torque is 200 foot-pounds.

RT-SVX28E-EN 49

Page 50

Installation

NOTICE:

Over Tightening!

Do not use Teflon-based products for any field connections because their high lubricity could allow connections to be over-tightened, resulting in damage to the coil header.

NOTICE:

Equipment Damage!

Properly seal all penetrations in unit casing. Failure to seal penetrations from inner panel to outer panel may result in unconditioned air entering the module, which could result in equipment damage.

• After completing the piping connections, seal around pipe from inner panel to outer panel.

NOTICE:

Coil Damage!

Failure to properly protect coils not in use during freezing temperatures could result in coil freeze-up damage.

Note: If glycol is used in the hot water system, be sure to use a glycol approved for use with

commercial heating systems and copper tube coils. Follow the manufacturer's recommendations for water treatment and mix. Failure to do so could affect coil performance or damage the tubes or braze joints.

Table 20. Hot water and steam coil connection sizes

Hot Water Coil Steam Coil

Casings Supply Return

A-C 2 ½2 ½ ½ 3.0 1 ¼1 ¼

Notes:

1. Type W coils, with center offset headers, are used in Hot Water units; Type NS coils are used in Steam units.

2. Hot water and Steam units have multiple headers.

3. All sizes are in inches.

4. All connection threads are internal.

Drain/

Vent Supply Return Vent

Table 21. Hot water and steam heat connection dimensions

Casings A B Y Diameter

A-C 276 9/16 290 5/16 18 5

50 RT-SVX28E-EN

Page 51

Figure 26. Hot water and steam heat connection locations

Supply Air Opening

Return Air Opening

Unit bottom view

Inlet

Outlet

Recommended

Figure 27. Hot water coil piping

Installation

RT-SVX28E-EN 51

Page 52

Installation

Figure 28. Steam coil piping

Chilled Water Units

Chilled water coils are factory installed inside the cooling section of the unit. Once the unit is set into place, the chilled water piping, external piping enclosure, and appropriate modulating valve (factory provided) must be installed.

Important: Supply, return, and vent connections, control valve, and actuator must be field

installed.

General Coil Piping Recommendations

1. Support all field-installed piping independently from the cooling coil.

2. When attaching the piping to the coil header, make the connection only tight enough to prevent leaks. Maximum recommended torque is 200 pound-feet.

NOTICE:

Coil Header Damage!

Use a backup wrench when attaching piping to coils with copper headers to prevent damage to the coil header. Do not use brass connectors because they distort easily and could cause connection leaks.

52 RT-SVX28E-EN

Page 53

Installation

NOTICE:

Over Tightening!

Teflon tape or piping compound should not be used for any field connections because its high lubricity may allow connections to be overtightened, resulting in damage to the coil header.

3. Use a short nipple on the coil headers prior to making any welded flange or welded elbow type connections.

4. Use swing joints or flexible connectors adjacent to the cooling coil. (These devices will absorb the strains of expansion and contraction).

5. All return lines and fittings must be equal to the diameter of the "outlet" connection on the chilled water coil. Table 22, p. 54

6. Coils should be installed with field fitted drains and vents to permit winterization of coils not in use and to assist in evacuating air from the chilled water system during start-up. See coil winterization for more details.

7. The Types 5W and W cold water coils are self-venting only when the tube water velocity exceeds

1.5 feet per second (fps). If the tube velocity is less than 1.5 feet per second, either:

a. install an automatic air vent at the top of the return header, using the tapped pipe connection

or,

b. vent the coil from the top of the return header down to the return piping. At the vent

connection, size the return piping to provide sufficient water velocity.

8. The Types WD cold water coils are self-venting only when the tube water velocity exceeds 2.5 feet per second (fps). If the tube velocity is less than 2.5 feet per second, either:

a. install an automatic air vent at the top of the return header, using the tapped pipe connection

or,

b. vent the coil from the top of the return header down to the return piping. At the vent

connection, size the return piping to provide sufficient water velocity.

9. Use the provided piping gasket and sealing ring on the sections of pipe penetrating the unit cabinet. See Figure 29, p. 54 and Figure 30, p. 55.

NOTICE:

Equipment Damage!

Properly seal all penetrations in unit casing. Failure to seal penetrations from inner panel to outer panel may result in unconditioned air entering the module which could result in equipment damage.

10. Seal the piping penetration on both sides of the cabinet wall before piping insulation.

11. Install the 3-way valve in an upright position. Ensure that the valve location lends itself to serviceability and is protected from freezing temperatures.

12. Install the actuator in a location protected from moisture and freezing temperatures. Actuator control wiring is located in the chilled water section of the unit.

Note: Space inside the piping enclosure limits the ability to house control valves and actuators

along with coil supply and return piping.

Important: Valve actuators are not waterproof. Failure to protect the valve from moisture may

result in the loss of cooling control.

RT-SVX28E-EN 53

Page 54

Installation

NOTICE:

Coil Damage!

Failure to properly protect coils not in use during freezing temperatures could result in coil freeze-up damage.

Table 22. Chilled water connection sizes (in.)

Chilled Water Coil Connection Sizes

Coil Type Supply Return Drain/Vent

5W 2 1/2 2 1/2 1/2

W 2 1/2 2 1/2 1/2

WD 2 1/2 2 1/2 1/2

Figure 29. Chilled water piping locations

54 RT-SVX28E-EN

Page 55

Figure 30. Chilled water piping penetration seal

Type WD Coils Type 5W & W Coils

Installation

Coil Winterization

Figure 31. Chilled water piping schematic

When applying air handlers with a chiller water coil and an economizer, the coil should be completely drained for winter operation. If the coil can not be completely drained, the coil should be filled with a glycol mixture that will protect the solution from freezing due to winter ambient temperatures.

NOTICE:

Coil Damage!

Failure to properly protect coils not in use during freezing temperatures could result in coil freeze-up damage.

RT-SVX28E-EN 55

Page 56

Installation

Important: If glycol is used in the chilled water system, be sure to use a glycol approved for use

with commercial cooling systems and copper tube coils. Follow the manufacturer's recommendations for water treatment and mix. Failure to do so could affect coil performance or damage the tubes or braze joints.

External Piping Enclosure Installation

Installation of the external piping enclosure requires assembly of the curb and installing the enclosure to both the unit baserail and unit cabinet as described below.

The pipe cabinet should be supported by chains, spreader bar, or other means when installing (see lifting instructions section). Mounting hardware, caulk, piping boot and sealing rings are located inside the piping enclosure skid.

1. Verify that the piping enclosure roof curb was properly installed. See roof curb installation manual for more information.

2. Remove paper backing on butyl tape from back and bottom of external piping enclosure.

Figure 32, p. 57

3. Set external piping enclosure on curb. Figure 33, p. 57

4. Ensure enclosure-to-curb seal is tight and without buckles or cracks.

5. Attach external piping enclosure top and side flanges to air handler cabinet panel with #14 drill screws. Figure 33, p. 57

Notes:

• Use force to compress the gasket between piping enclosure and the main unit cabinet while

drilling screws.

• Use all holes in the attachment flanges.

6. Attach the external piping enclosure baserail flanges to air handler unit base rail with #14 drill screws. Figure 33, p. 57

7. Remove external piping enclosure access panel. Figure 34, p. 57

Note: Only remove outside perimeter bolts to remove access panel.

8. Attach condensate drain hole blockoff to air handler cabinet panel with #14 drill screws.

Figure 35, p. 58

9. Apply caulk around the inside and outside perimeter of the external piping enclosure.

10. Seal condensate drain hole extension with pipe gasket and sealing plate using #14 drill screws.

Figure 12, p. 31

11. Re attach access panel to external piping enclosure.

Notes:

• When locating the access panel, first slide the panel into the roof slot. Next grab the handle and

use force to compress roof gasket. Then slide bottom into place over baserail gasket.

• Use all access panel bolt holes for reattachment to prevent water leakage.

56 RT-SVX28E-EN

Page 57

Installation

Butyl Tape Backing

Unit Attachment

Flanges

Only Remove Outside

Perimeter Bolts for

Access Panel

Removal

Figure 32. External piping enclosure butyl tape backing

Figure 33. External Piping enclosure installation Figure 34. External piping enclosure access panel

RT-SVX28E-EN 57

Page 58

Installation

Electrical Data

Disconnect Switch w/External Handle

Units come equipped with a factory mounted disconnect switch with an externally mounted handle. This allows the operator to disconnect power from the unit without having to open the control panel door. The handle locations and its three positions are shown below;

"ON" - Indicates that the disconnect switch is closed, allowing the main power supply to be applied at the unit.

"OFF" - Indicates that the disconnect switch is open, interrupting the main power supply to the unit controls.

"OPEN COVER/RESET" - Turning the handle to this position releases the handle from the disconnect switch, allowing the control panel door to be opened.

Once the door has been opened, it can be closed with the handle in any one of the three positions outlined above, provided it matches the disconnect switch position. The handle can be locked in the "OFF" position. While holding the handle in the "OFF" position, push the spring loaded thumb key, attached to the handle, into the base slot. Place the lock shackle between the handle and the thumb key. This will prevent it from springing out of position.

An overall layout of the field required power wiring is illustrated beginning with Figure 36, p. 59. To insure that the unit supply power wiring is properly sized and installed, follow these guidelines.

Note: All field installed wiring must conform to NEC guidelines as well as State and Local codes.

Figure 35. Disconnect switch external

handle

WARNING

Live Electrical Components!

During installation, testing, servicing and troubleshooting of this product, it may be necessary to work with live electrical components. Have a qualified licensed electrician or other individual who has been properly trained in handling live electrical components perform these tasks. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury.

Verify that the power supply available is compatible with the unit nameplate rating for all components. The available power supply must be within 10% of the rated voltage stamped on the nameplate. Use only copper conductors to connect the 3-phase power supply to the unit.

NOTICE:

Use Copper Conductors Only!

Unit terminals are not designed to accept other types of conductors. Failure to use copper conductors could result in equipment damage.

Electric Heat Units

Electric Heat Units require one power entry as illustrated in Figure 36, p. 59. Use the information provided in Table 23, p. 62 and the "Power Wire Sizing & Protection Device Equations", to determine the appropriate wire size and Maximum Over current Protection for the heaters/unit.

Important: Each power supply must be protected from short circuit and ground fault conditions.

To comply with NEC, protection devices must be sized according to the "Maximum

58 RT-SVX28E-EN

Page 59

Provide grounding for the supply power circuit in the electric heat control box.

Field Supplied Survice Over Current Protection

Pitch Pocket

3-Wire Power Supply+Ground

Front View Control Box

1TB1

1S1

Electric Heat Control Panel Gas Heat Control Panel Steam or Hot Water Control Panel

Heat Control Box

Main Unit Power Wiring

Figure 38, p. 60 lists the field connection wire ranges for both the main power terminal block and

the optional main power disconnect switch. The electrical tables beginning with Table 23, p. 62 list the component electrical data. The electrical service must be protected from over current and short circuit conditions in accordance with NEC requirements. Protection devices must be sized according to the electrical data on the nameplate. Refer to the "Power Wire Sizing and Protection Device Equations", for determining;

a. the appropriate electrical service wire size based on "Minimum Circuit Ampacity" (MCA),

b. the "Maximum Over current Protection" (MOP) device,

c. the "Recommended Dual Element fuse size" (RDE).

1. Location for the electrical service entrance is illustrated in Figure 6, p. 24. Complete the unit power wiring connections onto either the main terminal block, or the factory mounted nonfused disconnect switch, inside the unit control panel. Refer to the customer connection diagram that shipped with the unit for specific termination points.

2. Provide proper grounding for the unit in accordance with local and national codes.

Figure 36. Typical field power wiring

Installation

Over current Protection" (MOP) or "Recommended Dual Element" (RDE) fuse size data on the unit nameplate.

RT-SVX28E-EN 59

Page 60

Installation

COOLING SECTION

Note: DISCONNECT SWITCH SIZE IS

CALCULATED BY SELECTING THE SIZE GREATER THAN OR EQUAL TO 1.15 X (SUM OF UNIT LOADS). SEE UNIT LITERATURE FOR UNIT LOAD VALUES.

BLOCK SIZE WIRE QTY CONNECTOR WIRE RANGE

760 AMP (2)

SW ITCH SIZE

WIRE QTY CONNECTOR WIRE RANGE

250 AMP (1)

400 AMP (1)

OR (2)

600 AMP (2)

OR (3)

800 AMP (2)

OR (3)

250 - 500 MCM

3/0 - 500 MCM

250 - 500 MCM

3/0 - 500 MCM

DISCONNECT SW ITCH (ALL VOLTAGES)

#4 - 500 MCM

#1 - 600 MCM

#1 - 250 MCM

UNITS W ITH M AIN P OW ER

TERMINAL BLOCK (ALL VOLTAGES)

#4 - 500 MCM

UNITS W ITH M AIN P OW ER

Figure 37. Typical field power wiring

Figure 38. Customer connection wire range

60 RT-SVX28E-EN

Page 61

Power Wire Sizing and Protection Devices

To correctly size electrical service wiring for a unit, find the appropriate calculations listed below. Each type of unit has its own set of calculations for MCA (Minimum Circuit Ampacity), MOP (Maximum Overcurrent Protection), and RDE (Recommended Dual Element fuse size). Read the load definitions that follow and then find the appropriate set of calculations based on unit type.

Note: Set 1 is for cooling only and cooling with gas heat units, and set 2 is for cooling with electric

heat units.

Load Definitions: (To determine load values, see the Electrical Service Sizing Data Tables on the following page.)

LOAD1 = CURRENT OF THE LARGEST MOTOR (COMPRESSOR OR FAN MOTOR)

LOAD2 = SUM OF THE CURRENTS OF ALL REMAINING MOTORS

LOAD3 = CURRENT OF ELECTRIC HEATERS

LOAD4 = ANY OTHER LOAD RATED AT 1 AMP OR MORE

Set 1. Cooling Only Air Handler Units and Cooling with Gas Heat Air Handler Units

MCA = (1.25 x LOAD1) + LOAD2 + LOAD4

MOP = (2.25 x LOAD1) + LOAD2 + LOAD4

Select a fuse rating equal to the MOP value. If the MOP value does not equal a standard fuse size as listed in NEC 240-6, select the next lower standard fuse rating.

Note: If selected MOP is less than the MCA, then select the lowest standard maximum fuse size

which is equal to or larger than the MCA, provided the selected fuse size does not exceed 800 amps.

RDE = (1.5 x LOAD1) + LOAD2 + LOAD4

Select a fuse rating equal to the RDE value. If the RDE value does not equal a standard fuse size as listed in NEC 240-6, select the next higher standard fuse rating.

Note: If the selected RDE is greater than the selected MOP value, then select the RDE value to equal

the MOP value.

Installation

Set 2. Air Handler Units with Electric Heat

To arrive at the correct MCA, MOP, and RDE values for these units, two sets of calculations must be performed. First calculate the MCA, MOP, and RDE values as if the unit was in cooling mode (use the equations given in Set 1). Then calculate the MCA, MOP, and RDE values as if the unit were in the heating mode as follows.

(Keep in mind when determining LOADS that the compressors don't run while the unit is in the heating mode).

MCA = 1.25 x (LOAD1 + LOAD2 + LOAD4) + LOAD3

The nameplate MCA value will be the larger of the cooling mode MCA value or the heating mode MCA value calculated above.

MOP = (2.25 x LOAD1) + LOAD2 + LOAD3 + LOAD4

The selection MOP value will be the larger of the cooling mode MOP value or the heating mode MOP value calculated above.

Select a fuse rating equal to the MOP value. If the MOP value does not equal a standard fuse size as listed in NEC 240-6, select the next lower standard fuse rating.

Note: If selected MOP is less than the MCA, then select the lowest standard maximum fuse size

which is equal to or larger than the MCA, provided the selected fuse size does not exceed 800 amps.

RT-SVX28E-EN 61

Page 62

Installation

RDE = (1.5 x LOAD1) + LOAD2 + LOAD3 + LOAD4

The selection RDE value will be the larger of the cooling mode RDE value or the heating mode RDE value calculated above. Select a fuse rating equal to the RDE value. If the RDE value does not equal a standard fuse size as listed in NEC 240-6, select the next higher standard fuse rating.

Notes:

• If the selected RDE is greater than the selected MOP value, then select the RDE value to equal

the MOP value.

• On air handler units, the selected MOP value is stamped in the MOP field on the nameplate.

Table 23. Electrical service sizing data—motors

Supply Fan Motors

460 V 575 V

Motor Horsepower

15 18.9 15.1

20 24.7 19.6

25 31.0 24.5

30 36.6 29.2

40 47.6 39

50 60.5 48

60 71.5 57.2

75 90 72

100 115 92

Exhaust/Return Fan Motors

Motor Horsepower

7.5 9.4 8.2

10 12.6 10.1

15 18.9 15.1

20 24.7 19.6

25 31 24.5

30 36.6 29.2

40 47.6 39

50 60.5 48

FLA FLA

460 V 575 V

FLA FLA

Table 24. Electrical service sizing data—electric heat module (electric heat units only)

Voltage

460 575

Module kW

90 108.3 86.6

140 168.4 134.7

265 318.8 255

300 360.8 288.7

62 RT-SVX28E-EN

FLA FLA

Page 63

Installation

Table 25. Electrical service sizing data—control power transformer (heating mode only)

Voltages

Unit Size

A, B, C

Digit 2 Unit

Function

E, L, S, X 3 3

F (850 MBH) 4 4

F (1100 MBH) 4 4

F (1800 MBH) 4 4

Table 26. Voltage utilization range

Unit Voltage

460/60/3 414-506

575/60/3 517-633

Table 27. Electrical service sizing data - convenience outlet transformer

Nominal Tons Voltage

460 575

FLA Add FLA Add

Casings A-C 3.3 2.6

460 575

FLA FLA

RT-SVX28E-EN 63

Page 64

Controls

Hazardous Voltage!

Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to disconnect power before servicing could result in death or serious injury.

Proper Field Wiring and Grounding Required!

Field Installed Control Wiring

The Rooftop Module (RTM) must have a mode input in order to operate the air handler. The flexibility of having several system modes depends upon the type of sensor and/or remote panel selected to interface with the RTM. An overall layout of the various control options available, with the required number of conductors for each device, is illustrated beginning with Figure 39, p. 73.

Note: All field wiring must conform to NEC guidelines as well as state and local codes.

The various field installed control panels, sensors, switches, and contacts discussed in this section require both AC and DC consideration. These diagrams are representative of standard applications and are provided for general reference only. Always refer to the wiring diagram that shipped with the unit for specific electrical schematic and connection information.

WARNING

Controls using 24 VAC

Before installing any connecting wiring, refer to Figure 7, p. 26 for the electrical access locations provided on the unit and Tab le 28 , p. 6 4 for AC conductor sizing guidelines, and;

1. Use copper conductors unless otherwise specified.

2. Ensure that the AC control wiring between the controls and the unit's termination point does

not exceed three (3) ohms/conductor for the length of the run.

Equipment Damage!

Resistance in excess of 3 ohms per conductor could cause component failure due to insufficient AC voltage supply.

Important: Be sure to check all loads and conductors for grounds, shorts, and miswiring.

Table 28. AC conductors

Distance from

Unit to Control

000-460 feet 18 gauge

461-732 feet 16 gauge

733-1000 feet 14 gauge

3. Do not run the AC low voltage wiring in the same conduit with the high voltage power wiring.

NOTICE:

Recommended

Wire Size

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Controls using DC Analog Input/Outputs

Before installing any connecting wiring between the unit and components utilizing a DC analog input\output signal, refer to the appropriate illustration in Figure 7, p. 26 for the electrical access locations provided on the unit and Table 28, p. 64 for conductor sizing guidelines and;

1. Use standard copper conductor thermostat wire unless otherwise specified.

2. Ensure that the wiring between the controls and the unit termination point does not exceed two

and a half (2.5) ohms/conductor for the length of the run.

Important: Resistance in excess of 2.5 ohms per conductor can cause deviations in the accuracy

of the controls.

Table 29. DC conductors

Controls

Distance from

Unit to Control

000-150 feet 22 gauge

151- 240 feet 20 gauge

241- 385 feet 18 gauge

386- 610 feet 16 gauge

611- 970 feet 14 gauge

3. Do not run the electrical wires transporting DC signals in or around conduit housing high voltage wires.

Recommended

Wire Size

Units equipped with a Trane BACnet Communication Interface (BCI) or LonTalk communication Interface (LCI) option which utilizes a serial communication link;

1. Must be 18 AWG shielded twisted pair cable (Belden 8760 or equivalent).

2. Must not exceed 5,000 feet maximum for each link.

3. Must not pass between buildings.

Constant Volume System Controls

Remote Panel w/o NSB—BAYSENS110*

This electronic sensor features four system switch settings (Heat, Cool, Auto, and Off) and two fan settings (On and Auto) with four system status LED's. It is a manual or automatic changeover control with dual setpoint capability. It can be used with a remote zone sensor BAYSENS077*. Refer to Table 30, p. 71 for the Temperature vs. Resistance coefficient.

Constant Volume Zone Panel -BAYSENS108*

This electronic sensor features four system switch settings (Heat, Cool, Auto, and Off) and two fan settings (On and Auto). It is a manual or automatic changeover control with dual setpoint capability.

Variable Air Volume System Controls

Remote Panel w/o NSB -BAYSENS021*

The remote panel w/o Night setback has a system switch as well as a S/A temperature setpoint indicator, a local sensor, and four LED's. These features allow the operator to control system operation, and monitor unit operating status from a remote location. Use the installation instructions that shipped with the panel to install it, and the unit field wiring diagram to connect it to the unit.

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VAV Changeover Contacts

These contacts are connected to the RTM when daytime heating on VAV units with internal or external hydronic heat is required. Daytime (occupied) heating switches the system to a CV type mode of operation. Refer to the unit wiring diagram for the field connection terminals in the unit control panel. The switch must be rated at 12 ma @ 24 VDC minimum.

Constant Volume or Variable Air Volume System Controls

Remote Panel w/ NSB -BAYSENS119*

This 7 day programmable sensor features four periods for Occupied\Unoccupied programming per day. Either one or all four periods can be programmed. If the power is interrupted, the program is retained in permanent memory. If power is off longer than 2 hours, only the clock and day may have to be reset.

The front panel allows selection of Occupied/Unoccupied periods with two temperature inputs (Cooling Supply Air Temperature and Heating Warm-up temperature) per occupied period. The occupied cooling setpoint ranges between 40 and 80 Fahrenheit. The warm-up setpoint ranges between 50 and 90 degrees Fahrenheit with a 2 degrees deadband. The Unoccupied cooling setpoint ranges between 45 and 98 degrees Fahrenheit. The heating setpoint ranges between 43 and 96 degrees Fahrenheit.

The liquid crystal display (LCD) displays zone temperature, temperature setpoints, week day, time, and operational mode symbols.

The DIP switches on the subbase are used to enable or disable applicable functions, i.e.; Morning warm-up, economizer minimum position override during unoccupied status, heat installed, remote zone temperature sensor, 12/24 hour time display, and daytime warm-up. Refer to Table 30, p. 71 for the Temperature vs. Resistance coefficient.

During an occupied period, an auxiliary relay rated for 1.25 amps @ 30 volts AC with one set of single pole double throw contacts is activated.

Remote Human Interface Module

The remote Human Interface module enables the operator to set of modify the operating parameters of the unit using it's 16 key keypad and view the operating status of the unit on the 2 line, 40 character LCD screen without leaving the building. However, the Remote Human Interface module can not be used to perform any service functions.

One remote panel is designed to monitor and control up to four units providing each of the units are equipped with an IPCB module. Use the installation instructions that shipped with the module to install it, and the appropriate illustrations beginning with Figure 39, p. 73 to connect it to the unit.

Remote Zone Sensor (BAYSENS073*)

This electronic analog sensor features remote zone sensing and timed override with override cancellation. It is used when the RTM has been programmed as the source for zone temperature control. Refer to Table 30, p. 71 for the Temperature vs. Resistance coefficient.

Remote Zone Sensor (BAYSENS074*)

This electronic analog sensor features single setpoint capability and timed override with override cancellation. It is used with a Trane Integrated Comfort Temperature vs. Resistance coefficient.

system. Refer to Table 30, p. 71 for the

Remote Zone Sensor (BAYSENS016*)

This bullet type analog Temperature sensor can be used for; outside air (ambient) sensing, return air temperature sensing, supply air temperature sensing, remote temperature sensing (uncovered), morning warm-up temperature sensing, and for VAV zone reset. Wiring procedures vary according to the particular application and equipment involved. When this sensor is wired to

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a BAYSENS119* Remote Panel, wiring must be 18 AWG Shielded Twisted Pair (Belden 8760 or equivalent). Refer to Table 30, p. 71 for the Temperature vs. Resistance coefficient.

Remote Zone Sensor (BAYSENS077*)

This electronic analog sensor can be used with BAYSENS019*, 020*, or 021* Remote Panels. When this sensor is wired to a BAYSENS019* or BAYSENS020* Remote Panel, wiring must be 18 AWG Shielded Twisted Pair (Belden 8760 or equivalent). Refer to the specific Remote Panel for wiring details.

CO2 Sensing—Space or Duct

The CO2 sensor shall have the ability to monitor space occupancy levels within the building by measuring the parts per million of CO outside air damper modulates to meet the CO2 space ventilation requirements

2 (Carbon Dioxide) in the air. As the CO2 levels increase, the

Remote Minimum Position Potentiometer (BAYSTAT023*)

The remote minimum position potentiometer is used on units with an economizer. It allows the operator to remotely set the economizer minimum position (which controls the amount of outside air entering the unit). Use the installation instructions that shipped with the potentiometer to install it, and the appropriate illustrations beginning with Figure 39, p. 73 to connect it to the unit.

External Auto/Stop Switch

A field supplied single pole single throw switch may be used to shut down the unit operation. This switch is a binary input wired to the RTM. When opened, the unit shuts down immediately and can be cancelled by closing the switch.

Refer to the appropriate illustrations beginning with Figure 39, p. 73 for the proper connection terminals in the unit control panel. The switch must be rated for 12 ma @ 24 VDC minimum.

Emergency Override

When a LonTalk/BACnet communication module is installed, the user can initiate from the Trane Tracer Summit or 3rd party BAS one of five (5) predefined, not available to configure, Emergency Override sequences. The Humidification output is deenergized for any Emergency Override sequence. Each Emergency Override sequence commands the unit operation as follows:

1. PRESSURIZE_EMERG:

2. EMERG_DEPRESSURIZE:

– Supply Fan - On

– Supply Fan VFD Open/Max (if so equipped)

– Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

– OA Dampers - Open; Return Damper - Closed

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized (if so equipped)

– Preheat Output - Off

– Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

– Return VFD - Min (if so equipped)

– Supply Fan - Off

– Supply Fan VFD - Closed/Min (if so equipped)

– Exhaust Fan - On; Exhaust Dampers Open/Max (if so equipped)

– OA Dampers - Closed; Return Damper - Open

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– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized (if so equipped)

– Preheat Output - Off

– Return Fan - On; Exhaust Dampers - Open (if so equipped)

– Return VFD - Max (if so equipped)

3. EMERG_PURGE:

– Supply Fan - On

– Supply Fan VFD - Open/Max (if so equipped)

– Exhaust Fan - On; Exhaust Dampers Open (if so equipped)

– OA Dampers - Open; Return Damper - Closed

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized (if so equipped)

– Preheat Output - Off

– Return Fan - On; Exhaust Dampers - Open (if so equipped)

– Return VFD - Max (if so equipped)

4. EMERG_SHUTDOWN:

– Supply Fan - Off

– Supply Fan VFD - Closed/Min (if so equipped)

– Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

– OA Dampers - Closed; Return Damper - Open

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized (if so equipped)

– Preheat Output - Off

– Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

– Return VFD - Min (if so equipped)

5. EMERG_FIRE - Input from fire pull box/system:

– Supply Fan - Off

– Supply Fan VFD - Closed/Min (if so equipped)

– Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

– OA Dampers - Closed; Return Damper - Open

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized (if so equipped)

– Preheat Output - Off

– Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

– Return VFD - Min (if so equipped)

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Ventilation Override Module (VOM)

Important: The ventilation override system should not be used to signal the presence of smoke

caused by a fire as it is not intended nor designed to do so.

The user can customize up to five (5) different override sequences for purposes of ventilation override control. If more than one VOM sequence is being requested, the sequence with the highest priority is initiated first. Sequence hierarchy is the sequence “A” (UNIT OFF) is first, with sequence “E” (PURGE with Duct Pressure Control) last.

A ventilation override mode can be initiated by closing any of the five (5) corresponding binary input on the VOM module. A binary output is provided on the VOM module to provide remote indication of an active VOM mode. The Humidification output is deenergized for any VOM sequence. The factory default definitions for each mode are as follows:

1. UNIT OFF sequence “A”

When complete system shutdown is required the following sequence can be used.

– Supply Fan - Off

– Supply Fan VFD - Closed/Min (if so equipped)

– Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

– OA Dampers - Closed; Return Damper - Open

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Deenergized

– VOM Relay - Energized

– Preheat Output - Off

– Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

– Return VFD - Min (if so equipped)

– OA Bypass Dampers - Open (if so equipped)

– Exhaust Bypass Dampers - Open (if so equipped)

2. PRESSURIZE sequence “B”

Perhaps a positively pressurized space is desired instead of a negatively pressurized space. In this case, the supply fan should be turned on with the VFD at 100% speed and exhaust fan should be turned off.

– Supply Fan - On

– Supply Fan VFD - Max (if so equipped)

– Exhaust Fan - Off; Exhaust Dampers Closed (if so equipped)

– OA Dampers - Open; Return Damper - Closed

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized

– Preheat Output - Off

– Return Fan - Off; Exhaust Dampers - Closed (if so equipped)

– Return VFD - Min (if so equipped)

– OA Bypass Dampers - Open (if so equipped)

– Exhaust Bypass Dampers - Open (if so equipped)

3. EXHAUST sequence “C”

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With only the exhaust fans running (supply fan off), the space that is conditioned by the air handler would become negatively pressurized. This is desirable for clearing the area of smoke from the now-extinguished fire, possibly keeping smoke out of areas that were not damaged.

– Supply Fan - Off

– Supply Fan VFD - Closed/Min (if so equipped)

– Exhaust Fan - On; Exhaust Dampers Open (if so equipped)

– OA Dampers - Closed; Return Damper - Open

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Deenergized

– VOM Relay - Energized

– Preheat Output - Off

– Return Fan - On; Exhaust Dampers - Open (if so equipped)

– Return VFD - Max (if so equipped)

– OA Bypass Dampers - Open (if so equipped)

– Exhaust Bypass Dampers - Open (if so equipped)

4. PURGE sequence “D”

Possibly this sequence could be used for purging the air out of a building before coming out of Unoccupied mode of operation on VAV units or for the purging of smoke or stale air if required after a fire.

– Supply Fan - On

– Supply Fan VFD - Max (if so equipped)

– Exhaust Fan - On; Exhaust Dampers Open (if so equipped)

– OA Dampers - Open; Return Damper - Closed

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized

– Preheat Output - Off

– Return Fan - On; Exhaust Dampers - Open (if so equipped)

– Return VFD - Max (if so equipped)

– OA Bypass Dampers - Open (if so equipped)

– Exhaust Bypass Dampers - Open (if so equipped)

5. PURGE with duct pressure control sequence “E”

This sequence can be used when supply air control is required for smoke control.

– Supply Fan - On

– Supply Fan VFD - (If so equipped) Controlled by Supply Air Pressure Control function;

Supply Air Pressure High Limit disabled

– Exhaust Fan - On; Exhaust Dampers Open (if so equipped)

– OA Dampers - Open; Return Damper - Closed

– Heat - All heat stages off; Mod Heat output at 0 VDC

– Occupied/Unoccupied/VAV box output - Energized

– VOM Relay - Energized

– Preheat Output - Off

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– Return Fan - On; Exhaust Dampers - Open (if so equipped)

– Return VFD - Max (if so equipped)

– OA Bypass Dampers - Open (if so equipped)

– Exhaust Bypass Dampers - Open (if so equipped)

Temperature vs. Resistance Coefficient

The UCM network relies on various sensors located throughout the system to provide temperature information in the form of an analog input. All of the sensors used have the same temperature vs. resistance co-efficient and are made from Keystone Carbon D97 material with a 1 degree Centigrade tolerance.

Table 30. Temperature vs. resistance

Controls

Temperature (°F)

-40 346.1 71 11.6

-30 241.7 72 11.31

-20 170.1 73 11.03

-10 121.4 74 10.76

-5 103 75 10.5

0 87.56 76 10.25

5 74.65 77 10

10 63.8 78 9.76

15 54.66 79 9.53

20 46.94 80 9.3

25 40.4 85 8.25

30 34.85 90 7.33

35 30.18 100 5.82

40 26.22 105 5.21

45 22.85 110 4.66

50 19.96 120 3.76

55 17.47 130 3.05

60 15.33 140 2.5

65 13.49 150 2.05

66 13.15 160 1.69

67 12.82 170 1.4

68 12.5 180 1.17

69 12.19 190 0.985

70 11.89 200 0.83

Resistance

(in. 1000 Ohms) Temperature (°F)

Resistance

(in. 1000 Ohms)

Emergency Stop Switch

A normally closed (N.C.) switch wired to the RTM may be used during emergency situations to shut down all unit operations. When opened, an immediate shutdown occurs. An emergency stop diagnostic is entered into the Human Interface and the unit must be manually reset. Refer to the appropriate illustrations in Figure 40, p. 74 and Figure 41, p. 75 for the proper connection terminals in the unit control panel. The switch must be rated for 12 ma @ 24 VDC minimum.

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Occupied/Unoccupied Contacts

To provide Night Setback control if a remote panel with NSB was not ordered, a field supplied contact must be installed. This binary input provides the Occupied/Unoccupied status information of the building to the RTM. It can be initiated by a time clock, or a Building Automation System control output. The relay’s contacts must be rated for 12 ma @ 24 VDC minimum. Refer to the appropriate illustrations in Figure 40, p. 74 and Figure 41, p. 75 for the proper connection terminals in the unit control panel.

Demand Limit Relay

If the unit is equipped with a Generic BAS Module, a normally open (N.O.) switch may be used to limit the electrical power usage during peak periods. When demand limit is initiated, the mechanical cooling and heating operation is limited to either 50% or 100%. Demand limit can be initiated by a toggle switch closure, a time clock, or an ICS be rated for 12 ma @ 24 VDC minimum.

control output. These contacts must

Outside Air Sensor (BAYSENS016*)

This device senses the outdoor air temperature and sends this information in the form of an analog input to the RTM. It's factory installed on units with an economizer, but can be field provided/ installed and used for informational purposes on units without an economizer. Refer to the appropriate illustrations in Figure 40, p. 74 and Figure 41, p. 75 for the proper connection terminals in the unit control panel. Refer to Table 30, p. 71 for Temperature vs. Resistance coefficient.

Generic Building Automation System

The Generic Building Automation System (GBAS) module allows a non-Trane building control system to communicate with the air handler unit and accepts external setpoints in form of analog inputs for cooling, heating, demand limiting, and supply air pressure parameters. Refer to

Figure 44, p. 78 & Table 31, p. 79 for the input wiring to the GBAS module and the various desired

setpoints with the corresponding DC voltage inputs for both VAV and CV applications.

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Figure 39. Typical field wiring diagram for casings A-C CV control options

Notes: See notes Figure 43, p. 77

Source: 2309-3675

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Figure 40. Typical ventilation override binary output for casings A-C CV control options

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Notes: See Figure 43, p. 77

Source: 2309-3676 Source: 2309-3675

Figure 41. Typical field wiring diagram for casings A-C VAV control options

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Figure 42. Typical ventilation override binary output for casings A-C CV control options

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Figure 43. Typical field wiring diagram notes for VAV and CV control options

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Notes: See Figure 43, p. 77

Figure 44. Typical GBAS analog input wiring diagram for casings A-C CV and VAV control options

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Table 31. GBAS voltage vs. setpoint

Setpoint GBAS 0-5vdc GBAS 0-10vdc Valid Range

Occ Zone Cooling Setpoint(CV only) 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 90°F

Unocc Zone Cooling Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 90°F

Occ Zone Heating Setpoint(CV only) 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 90°F

Unocc Zone Heating Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 90°F

SA Cooling Setpoint (VAV only) 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 180°F

SA Heating Setpoint (VAV only) 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 180°F

Space Static Pressure Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc -0.20 to 0.30 IWC

SA Static Pressure Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 0.7 to 5.1 IWC

Min OA Flow Setpoint

MWU Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 90°F

Econ Dry Bulb Enable Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 50 to 140°F

SA_Reheat_Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 180°F

Minimum Position Setpoint

Occ Dehumidification Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 65%

Unocc Dehumidification Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 65%

Occ Humidification Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 65%

Unocc Humidification Setpoint 0.5 to 4.5vdc 0.5 to 9.5vdc 40 to 65%

Notes:

1. If DCV is enabled this is used for Design Minimum OA Flow Setpoint

2. If DCV is enabled, this is used for Design Minimum OA Damper Position Setpoint

0.5 to 4.5vdc 0.5 to 9.5vdc 0 to Unit Max Flow

0.5 to 4.5vdc 0.5 to 9.5vdc 0 to 100%

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Sequence of Operation

Cooling Sequence of Operation

Time delays are built into the controls to increase reliability and performance.

SZVAV Cooling Sequence of Operation

Single Zone VAV units will be equipped with a VFD controlled supply fan which will be controlled via the 0-10VDC RTM VFD output and the RTM Supply Fan output. With the RTM Supply Fan output energized and the RTM VFD output at 0Vdc the fan speed output is 37% (22Hz) from the VFD motor, by default, and at 10VDC the Fan Speed output is 100% (60Hz). The control scales the 0-10Vdc VFD output from the RTM linearly to control between the 37%-100% controllable range.

If the RTM determines that there is a need for active cooling capacity in order to meet the calculated Temperature Setpoint (Tset), the unit will begin to stage compressors accordingly once supply fan proving has been made. Note that the compressor staging order will be based on unit configuration and compressor lead/lag status.

Once the Tset calculation has reached its bottom limit (Tset Lower Limit Setpoint) and compressors are being utilized to meet the demand, the Tset value continues to calculate below the Tset Lower Limit Setpoint and the algorithm will begin to ramp the Supply Fan Speed up toward 100%. Note that the supply fan speed will remain at the compressor stage’s associated minimum value (as described below) until the Tset value is calculated below the Tset Lower Limit Setpoint.

As the cooling load in the zone decreases the zone cooling algorithm will reduce the speed of the fan down to minimum per compressor stage and control the compressor outputs accordingly. As the compressors begin to de-energize, the Supply Fan speed will fall back to the Cooling Stage’s associated minimum fan speed, but not below. As the load in the zone continues to drop cooling capacity will be reduced in order to maintain the discharge air within the ± ½ Tset deadband.

Cooling Stages Minimum Fan Speed

As the unit begins to stage compressors to meet the cooling demand, the following minimum Supply Fan Speeds will be utilized for each corresponding Cooling Stage. Note that the Supply Fan Speed will be allowed to ramp up beyond 37% as determined by the active Tset calculation; the speeds below are only the minimum speeds per cooling stage. Note that when transitioning between active cooling stages, compressors may energize prior to the supply fan reaching the minimum speed for the associated step.

1. 2-Stage DX Cooling - The minimum fan speed for units with 2 stages of DX Cooling will be 37% of the unit’s full airflow capacity. At Stage 1 of DX Cooling the minimum Fan Speed will be 37% and at Stage 2 of DX Cooling the Fan Speed will be at a minimum of 67%.

2. 3-Stage DX Cooling - There are no IntelliPak applications with 3 stages of DX Cooling.

3. 4-Stage DX Cooling - The minimum fan speed for units with 4 stages of DX Cooling will be 37% of the unit’s total airflow. At Stage 1 the minimum Supply Fan Speed will be 37%, at Stage 2 the minimum Supply Fan Speed will be 58%, and at Stages 3 & 4 the minimum Supply Fan Speed will be 67%.

Units without an Economizer

Upon entering an "occupied" mode of operation, the RTM receives input from the remote panel to start the supply fan. For constant volume applications, the RTM supply fan contacts close which energizes the supply fan contactor. When the supply fan starts, the fan proving switch closes, signaling the RTM that airflow has been established. The VFD will begin to ramp the fan (if equipped).

When a cooling request is sent to the RTM from a zone temperature sensor, the RTM evaluates the operating condition of the system using the supply air temperature input and the outdoor temperature input. before sending the request to the MCM.

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Units with an Economizer

When a cooling request is sent to the RTM from the zone temperature sensor, the RTM evaluates the operating condition of the system using the supply air temperature input and the outdoor temperature input before sending the request to the MCM for mechanical cooling.

Units with Traq™ Sensor

The fresh air enters the unit through the Traq Sensor assemblies and is measured by velocity pressure flow rings. The velocity pressure flow rings are connected to a pressure transducer/ solenoid assemblies. The solenoid is used for calibration purposes to compensate for temperature swings that could affect the transducer. The Ventilation Control Module (VCM) utilizes the velocity pressure inputs, the RTM outdoor air temperature input, and the minimum outside air CFM setpoint to modify the volume (CFM) of fresh air entering the unit as the measured airflow deviates from setpoint.

When the optional temperature sensor is installed and the Preheat function is enabled, the sensor will monitor the combined (averaged) fresh air and return air temperatures. As this mixed air temperature falls below the Preheat Actuate Temperature Setpoint, the VCM will activate the preheat binary output used to control a field installed heater. The output will be deactivated when the temperature rises 5 above the Preheat Actuate Temperature Setpoint.

When the optional CO to control CO2 concentrations. If the CO2 concentration is greater than the Design Minimum CO2 Setpoint the OA damper will be opened to the Design Minimum OA Damper Setpoint (w/o Traq) or until the Design Minimum OA Flow Setpoint is met (w/ Traq).

If the CO to the DCV Minimum OA Damper Setpoint (w/o Traqs) or until the DCV Minimum OA Flow Setpoint is met (w/ Traqs). If the CO DCV Minimum CO2 Setpoint the OA damper will be modulated proportionally between the Design Minimum OA Damper Setpoint and the DCV Minimum OA Damper Setpoint (w/ Traqs) and between the Design Minimum OA Flow Setpoint and the DCV Minimum OA Flow Setpoint (w/o Traqs).

concentration is less than the DCV Minimum CO2 Setpoint the OA damper will be closed

sensor is installed and DCV is enabled, the OA damper will be modulated

concentration is between the Design Minimum CO2 Setpoint and the

Units Equipped with 100% Modulating Exhaust

The exhaust dampers are controlled through an Exhaust/Comparative Enthalpy Module (ECEM). The ECEM module receives input from a space transducer and modulates the exhaust dampers to maintain the space pressure to within the specified setpoint controlband.

Gas Heating Sequence of Operation

Standard Two Stage Gas Furnace

The control system for air handler units is wired to ensure that the heating and cooling do not occur simultaneously. Refer to the wiring diagram that shipped with the unit while reviewing the following sequence of operation.

Honeywell Ignition System

(850 & 1100 MBH Two Stage Natural Gas)

When a heating requirement exists, the Rooftop Module (RTM) starts the supply fan and sends a request for heat to the Heat Module. The Heat Module closes contacts and starts the combustion blower motor. The combustion blower motor starts on low speed through the normally closed combustion blower relay contacts.

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The supply airflow switch and the combustion air switch closes. Power is applied through the high limit cutout to the Honeywell ignition control board. The ignition control board starts a pre-purge timing cycle. At the end of the pre-purge cycle, the ignition transformer and the pilot solenoid valve are energized. This starts a 10 second trial for pilot ignition. When the pilot flame is established and sensed by the flame sensing rod, stage 1 of the main gas valve and the 60 seconds sequencing time delay relay is energized.

The system will operate in the low heat mode until an additional call for heat is established by closing the contacts on the Heat Module.

The sequencing time delay relay will energize the combustion blower motor relay which switches the combustion blower motor to high speed and energizes the 2nd stage solenoid on the gas valve after approximately 60 seconds.

If the flame rod does not detect a pilot flame within the 10 second trial for ignition period, the control will lockout. If a flame failure occurs during operation, the gas valve, the sequencing time delay relay, and the combustion blower relay is de-energized. The system will purge and attempt to relight the pilot. If a flame is not detected after this attempt, the Honeywell ignition control will lock out. The combustion blower motor will continue to operate as long as a heating demand exists and the system switch is "On".

Once the heating demand has been satisfied, the combustion blower and the Honeywell ignition control board is de-energized.

Note: The above sequence is the same for Propane. The orifices are smaller and the manifolds are

adjusted to different values

(1800 MBH Two Stage Natural Gas)

At the end of the pre-purge cycle, the ignition transformer and the pilot solenoid valve are energized. This starts a 10-second trial for pilot ignition.

When the pilot flame is established and sensed by the flame sensing rod, the stage 1 of the main gas valve will begin. The gas butterfly control valve is in the low fire setting by the linkage arm connection between the combustion air actuator and the butterfly valve.

The system will operate in the low heat mode until there is an additional call for heat established by closing the contacts on the Heat Module.

If the flame rod does not detect a pilot flame within the 10 second trial for ignition period, the ignition control board will lockout. The combustion blower motor will continue to operate as long as a heating demand exists and the system switch is "On".

Once locked out on flame failure, the IC board will not reactivate the ignition/combustion control circuit until it is reset manually. To do this, press the reset button on the front of the IC board case.

A set of relay contacts is available for external use for heat fail (Information Only).

Once the heating demand has been satisfied, the combustion blower and the Honeywell ignition control board is de-energized.

Modulating Gas Sequence of Operation

The control system for air handler units is wired to ensure that the heating and cooling do not occur simultaneously. Refer to the modulating heat wiring diagram that shipped with the unit while reviewing the following sequence of operation. As you review the sequence of operation, keep the following in mind:

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Sequence of Operation

1. The furnace will not light unless the manual gas valves are open and the control circuit switch is closed.

2. The control systems are wired to ensure that heating and cooling cannot occur simultaneously.

3. The unit supply fans must run continuously so airflow switch will stay closed.

4. Modulating Gas heat is available during both occupied and unoccupied operation.

When there is a call for heat, the heat module energizes the combustion blower which causes the combustion air flow switch to close. The ignition control board will energize providing that the indoor air flow switch, high limit, and low and high pressure gas switches are closed.

The Low Pressure Gas Switch must be closed, indicating the required minimum gas pressure is present. The High Pressure Gas Switch must be closed, indicating the manifold pressure is not set too high. The ignition control board then causes the combustion air actuator to drive the inlet air damper to the fully open position for a 30 second pre-purge. The pre-purge time does not begin until the purge interlock switches are made.

After the pre-purge, the combustion air actuator drives the inlet air damper and the gas butterfly control valve to a nearly closed position for light off. When the Low fire interlock switch on is closed the ignition transformer is energized, the igniter begins to spark and the main valve and auxiliary gas valve open.

This begins a 10-second trial for ignition period during which the flame rod must detect the flame. If does not detect a flame at the end of the period, it will shut down and lock out the ignition/ combustion circuit.

Once the light off flame has been established, the heat module will drive the combustion air actuator to a firing rate based on a 2-10 VDC signal. The gas butterfly control valve will respond through the connecting linkage.

The heater will continue to run until the call for heat is removed or a limit opens. Following the completion of the call for heat, there is a 15-second post-purge.

Flame Failure

In the event that (IC) board loses the "proof-of-flame" input signal during furnace operation, it will lock out and the must be manually reset (Combustion blower motor continues to run as long as a heating requirement exists and control circuit switch is ON.)

Once locked out on flame failure, the (IC) board will not reactivate the ignition/combustion control circuit until it is reset manually. To do this, press the reset button on the front of the (IC) board case.

A set of relay contacts is available for external use for heat fail (Information Only).

Note: The modulating gas heaters are factory adjusted for the proper air/gas ratio at minimum and

nameplate rated firing MBH for most areas in the country.

Electric Heat Sequence of Operation

The control system for air handler units is wired to ensure that heating and cooling do not occur simultaneously. Refer to electric heat wiring diagrams that shipped with the unit while reviewing the following sequence of operation. As you review the sequence of operations, remember these points:

1. The high limit switch will trip if exposed to a temperature greater than the trip point, and will reset automatically once the temperature falls below the reset point.

2. The linear high limit switch is encased in a capillary that extends across the unit supply air opening. The limit will trip if any 6” span of the capillary exceeds the trip point.

3. Electric heat will only energize if both of the high limit safety controls are closed.

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Sequence of Operation

CV Electric Heat

CV electric heat operation is done with discrete stages of electric heat. Stages 2 and 3 will not energize unless Stage 1 is already operating and unable to satisfy the heating load. The heat will be staged to control to the Zone Temperature Heating Setpoint.

VAV Occupied Electric Heat

VAV occupied electric heating operation is done with discrete stages (steps) of electric heat. The heat staging is dependent on unit tonnage and heater selection. The heat will be staged to control to the Supply Air Heating Setpoint.

Demand Control Ventilation Sequence of Operation

Sequence of Operation without TRAQs

If the space CO2 level is greater than or equal to the Design Minimum CO2 Setpoint, the outdoor air damper will open to the Design Minimum Outdoor Air Damper Setpoint. If there is a call for economizer cooling, the damper may be opened further to satisfy the cooling request.

If the space CO damper will close to the DCV Minimum Outdoor Air Damper Setpoint. If there is a call for economizer cooling, the damper may be opened further to satisfy the cooling request.

If the space CO Minimum CO2 Setpoint, the outdoor air damper position is modulated proportionally to the space CO2 level relative to a target position between the DCV Minimum CO2 Setpoint and the Design Minimum CO to satisfy the cooling request.

level is less than or equal to the DCV Minimum CO2 Setpoint, the outdoor air

level is greater than the DCV Minimum CO2 Setpoint and less than the Design

Setpoint. If there is a call for economizer cooling, the damper may be opened further

Sequence of Operation with TRAQs

If the space CO2 level is greater than or equal to the Design Minimum CO2 Setpoint, the outdoor air damper will open to the Design Minimum Outdoor Air Flow Setpoint. If there is a call for economizer cooling, the damper may be opened further to satisfy the cooling request.

If the space CO damper will close to the DCV Minimum Outdoor Air Flow Setpoint. If there is a call for economizer cooling, the damper may be opened further to satisfy the cooling request.

If the space CO Minimum CO2 Setpoint, the outdoor air damper position is modulated proportionally to the space

level relative to a target position between the DCV Minimum CO2 Setpoint and the Design

Minimum CO2 Setpoint. If there is a call for economizer cooling, the damper may be opened further to satisfy the cooling request.

level is less than or equal to the DCV Minimum CO2 Setpoint, the outdoor air

level is greater than the DCV Minimum CO2 Setpoint and less than the Design

Return Fan Sequence of Operation

Whenever the Supply Fan is turned ON, the return fan will be turned ON. The speed of the return fan will control to the Return Air Plenum Pressure Target. The target is calculated internal to the control and will be between the Minimum Return Air Plenum Pressure Setpoint and the Maximum Return Air Plenum Pressure Setpoint depending on unit operation conditions. A Return Air Pressure High Limit will be set at 3.5 IWC. If the pressure inside the return plenum exceeds the limit the unit will shut down.

Wet Heat Sequence of Operation

Electrical circuitry for units with steam or hot water heat is limited to the connections associated with the modulating valve actuator and the freezestat. Like the furnaces described earlier, steam and hot water heat control systems are wired to ensure that simultaneous heating and cooling do not occur. The supply fan will cycle "On" and "Off" with each call for heat during both an occupied and unoccupied period.

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Sequence of Operation

Whenever there is a call for heat, the relay on the heat module energizes. This allows a modulated voltage signal to be sent to the "Wet” heat actuator. The value of this signal regulates the flow of steam or hot water through the coil by positioning the valve stem at some point between fully closed (6 VDC) and fully open (8.5 VDC).

Freeze Protection

A freezestat is mounted inside the heat section of hot water and steam heat units to prevent the “wet” heat coil from freezing during the "Off" cycle.

If the temperature of the air leaving the heating coils falls to 40 F, the freezestat normally open contacts close, completing the heat fail circuit on the UCM. When this occurs:

1. The supply fan is turned "Off".

2. "Wet” heat actuator fully opens to allow hot water or steam to pass through the heating coil and prevent freeze-up.

3. A "Heat Fail" diagnostic is displayed on the Human Interface LCD screen.

For heating control settings and time delay specifications, refer to Table 38, p. 113. Use the following checklist, in conjunction with the “General Unit Requirement" checklist”, to ensure that the unit is properly installed and ready for operation. Be sure to complete all of the procedures described in this section before starting the unit for the first time.

– Turn the field supplied disconnect switch, located upstream of the air handler unit, to the

"Off" position.

WARNING

Hazardous Voltage!

– Turn the 115 volt control circuit switch 1S1 to the "Off" position. It is located in the secondary

of the 1T1 transformer.

– Turn the 24 volt control circuit switch 1S70 to the "Off" position. It is located in the secondary

of the 1T2 & 1T3 transformers.

– Turn the "System" selection switch (at the Remote Panel) to the "Off" position and the "Fan"

selection switch (if Applicable) to the "Auto" or "Off" position.

– Check all electrical connections for tightness and "point of termination" accuracy.

Do not start the unit in the cooling mode if the ambient temperature is below the following minimum recommended operating temperature:

Standard unit with or without HGBP-+45 F

– Check the supply fan belts for proper tension and the fan bearings for sufficient lubrication.

If the belts require adjustment, or if the bearings need lubricating, refer to the Service/ Maintenance section of this manual for instructions.

– Inspect the interior of the unit for tools and debris. Install all panels in preparation for starting

the unit.

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Sequence of Operation

Table 32. Service test guide component operation

COMPONENT CONFIGURATION

COMPONENT

BEING TESTED

SUPPLY FAN

EXHAUST FAN

CHILLED WATER

GAS HEAT (Full

Capacity)

STAGE 1 ON OFF ON OFF N/A Closed Closed 100% Unocc

STAGE 2 ON OFF OFF ON N/A Closed Closed 100% Unocc

FULL MODULATING ON OFF 10% - 90% Closed Closed 100% Unocc

ELECTRIC HEAT

Stage 1 ON OFF ON OFF OFF Closed Closed 100% Unocc

Stage 2 ON OFF OFF ON OFF Closed Closed 100% Unocc

Stage 3 ON OFF OFF OFF ON Closed Closed 100% Unocc

HYDRONIC HEAT

FRESH AIR

DAMPERS

EXHAUST

DAMPERS

Supply

Fan

ON OFF OFF OFF OFF Closed Closed 100% Unocc

OFF ON OFF OFF OFF Closed Closed 100% Default

OFF OFF 100% Select Closed Closed 0% Default

ON OFF ON ON N/A Closed Closed 100% Unocc

ON OFF ON ON ON Closed Closed 100% Unocc

OFF OFF 100% Select Closed Closed 0% Default

OFF OFF 100% Select 100% Open Closed 0% Default

OFF OFF 100% Select 100% 100% Open 0% Default

Exhaust

Fan

Heat Stages

Econo

Damper

Exhaust Damper

Output123

VFD

Unocc

Relay

Verifying Proper Fan Rotation

1. Ensure that the "System" selection switch at the remote panel is in the "Off" position and the "Fan" selection switch for constant volume units is in the "Auto" position. (VAV units do not utilize a "Fan" selection input.)

2. Close the disconnect switch or circuit protector switch that provides the supply power to the unit terminal block 1TB1 or the unit mounted disconnect switch 1S14.

3. Turn the 115 volt control circuit switch 1S1 and the 24 volt control circuit switch 1S70 to the "On" position.

4. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the appropriate programming manual for CV or VAV applications for the SERVICE TEST screens and programming instructions.

5. Use Table 32, p. 86 to program the unit Fans for operation by scrolling through the displays. All Fans can be programmed to be "On", if desired. Verify proper fan rotation for VFDs with bypass.

6. Once the configuration for the Fans is complete, press the NEXT key until the LCD displays the “Start test in __Sec.” screen. Press the + key to designate the delay before the test is to start. This service test will begin after the TEST START key is pressed step has elapsed. Press the ENTER key to confirm this choice.

and the delay designated in this

Occ

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Sequence of Operation

WARNING

Rotating Components!

During installation, testing, servicing and troubleshooting of this product it may be necessary to work with live and exposed rotating components. Have a qualified or licensed service individual who has been properly trained in handling exposed rotating components, perform these tasks. Failure to follow all safety precautions could result in rotating components cutting and slashing technician which could result in death or serious injury.

7. Press the TEST START key to start the test. Remember that the delay designated in step 6 must elapse before the fans will begin to operate.

8. Check the supply fan and the exhaust fans (if equipped) for proper rotation. The direction of rotation is indicated by an arrow on the fan housings.

If all of the fans are rotating backwards

1. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

2. Open the field supplied disconnect switch upstream of the air handler unit. Lock the disconnect switch in the open position while working at the unit.

Hazardous Voltage!

3. Interchange any two of the field connected main power wires at the unit terminal block or the factory mounted disconnect switch.

Note: Interchanging "Load" side power wires at the fan contactors will only affect the individual

fan rotation. Ensure that the voltage phase sequence at the main terminal block or the factory mounted disconnect switch is ABC as outlined in the "Electrical Phasing" section.

If some of the fans are rotating backwards

1. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

2. Open the field supplied disconnect switch upstream of the air handler unit. Lock the disconnect switch in the open position while working at the unit.

3. Interchange any two of the fan motor leads at the contactor for each fan that is rotating backwards.

System Airflow Measurements

Constant Volume Systems

2. Close the disconnect switch or circuit protector switch that provides the supply power to the unit terminal block or the unit mounted disconnect switch.

WARNING

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Sequence of Operation

Hazardous Voltage!

HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR UNIT DISCONNECT SWITCH.

3. Turn the 115 volt control circuit switch and the 24 volt control circuit switch to the "On" position.

4. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the appropriate programming manual for CV applications for the SERVICE TEST screens and programming instructions.

5. Use Ta b le 32, p . 8 6 to program the Supply Fan for operation by scrolling through the displays.

6. Once the configuration for the Fan is complete, press the NEXT key until the LCD displays the “Start test in __Sec.” screen. Press the + key to designate the delay before the test is to start. This service test will begin after the TEST START key is pressed step has elapsed. Press the ENTER key to confirm this choice.

WARNING

and the delay designated in this

WARNING

Live Electrical Components!

7. Press the TEST START key to start the test. Remember that the delay designated in step 6 must elapse before the fans will begin to operate.

8. With the system in the SERVICE MODE and the supply fan rotating in the proper direction, measure the amperage at the supply fan contactors. If the amperage exceeds the motor nameplate value, the static pressure is less than design and the airflow is too high. If the amperage is below the motor nameplate value, static pressure may be too high and CFM may be too low. To determine the actual CFM (± 5%);

a. Measure the actual fan RPM

b. Calculate the Theoretical BHP

Actual Motor Amps

Motor Nameplate Amps

c. Plot this data onto the appropriate Fan Performance Curve beginning with Figure 12, p. 31.

Where the two points intersect, read straight down to the CFM line.

Use this data to assist in calculating a new fan drive if the CFM is not at design specifications.

An alternate method with less accuracy is to measure the static pressure drop across the chilled water coil. This can be accomplished by;

d. drilling a small hole through the unit casing on each side of the coil.

Note: Coil damage can occur if care is not taken when drilling holes in this area.

e. Measure the difference between the pressures at both locations.

X Motor HP

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Sequence of Operation

f. Plot this value onto the appropriate pressure drop curve beginning with Figure 39, p. 73. Use

the data in Table 22, p. 54 (Component Static Pressure Drops) to assist in calculating a new fan drive if the CFM is not at design specifications.

g. Plug the holes after the proper CFM has been established.

9. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

Variable Air Volume Systems

1. Ensure that the "System" selection switch at the remote panel is in the "Off" position.

2. Close the disconnect switch or circuit protector switch that provides the supply power to the unit terminal block or the unit mounted disconnect switch.

WARNING

Hazardous Voltage!

HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR UNIT DISCONNECT SWITCH.

3. Turn the 115 volt control circuit switch and the 24 volt control circuit switch to the "On" position.

4. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the appropriate Programming Manual for VAV applications for the SERVICE TEST screens and programming instructions.

Use Table 32, p. 86 to program the following system components for operation by scrolling through the displays:

Supply Fan,

Variable Frequency Drive (100% Output, if applicable),

RTM Occ/Unocc Output (Unoccupied)

5. Once the configuration for the components is complete, press the NEXT key until the LCD displays the “Start test in __Sec.” screen. Press the + key to designate the delay before the test is to start. This service test will begin after the TEST START key is pressed designated in this step has elapsed. Press the ENTER key to confirm this choice.

and the delay

WARNING

Live Electrical Components!

6. Press the TEST START key to start the test. Remember that the delay designated in step 6 must elapse before the fan will begin to operate.

7. With the VFD at 100% and the supply fan operating at full airflow capability, measure the amperage at the supply fan contactors. If the amperage exceeds the motor nameplate value,

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Sequence of Operation

the static pressure is less than design and the airflow is too high. If the amperage is below the motor nameplate value, static pressure may be too high and CFM may be too low. To determine the actual CFM (± 5%);

a. Measure the actual fan RPM

b. Calculate the Theoretical BHP

Actual Motor Amps

Motor Nameplate Amps

c. Plot this data onto the appropriate Fan Performance Curve beginning with Figure 39, p. 73.

Use this data to assist in calculating a new fan drive if the CFM is not at design specifications.

An alternate method with less accuracy is to measure the static pressure drop across the chilled water coil. This can be accomplished by:

d. drilling a small hole through the unit casing on each side of the coil.

Note: Coil damage can occur if care is not taken when drilling holes in this area.

e. Measure the difference between the pressures at both locations.

f. Plot this value onto the appropriate pressure drop curve beginning with Figure 39, p. 73. Use

g. Plug the holes after the proper CFM has been established. Press the STOP key at the Human

8. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

X Motor HP

Where the two points intersect, read straight down to the CFM line.

the data in Tab l e 23 , p. 62 (Component Static Pressure Drops) to assist in calculating a new fan drive if the CFM is not at design specifications.

Interface Module in the unit control panel to stop the fan operation.

Exhaust Airflow Measurement (Optional)

1. Close the disconnect switch or circuit protector switch that provides the supply power to the unit's terminal block or the unit mounted disconnect switch.

Hazardous Voltage!

HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR UNIT DISCONNECT SWITCH.

2. Turn the 115 volt control circuit switch and the 24 volt control circuit switch to the "On" position.

3. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the appropriate programming manual for CV or VAV applications for the SERVICE TEST screens and programming instructions.

4. Use Table 32, p. 86 to program the following system components for operation by scrolling through the displays:

Exhaust Fan,

Exhaust Dampers (100% Open, if applicable),

Fresh Air dampers (100% Open),

WARNING

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Sequence of Operation

Variable Frequency Drive (100%, if applicable),

RTM Occ/Unocc Output (Default)

and the delay

WARNING

Live Electrical Components!

6. Press the TEST START key to start the test. Remember that the delay designated in step 5 must elapse before the fans will begin to operate.

7. With the exhaust dampers open and the exhaust fan operating at full airflow capability, measure the amperage at the exhaust fan contactor. If the amperage exceeds the motor nameplate value, the static pressure is less than design and airflow is too high. If the amperage is below the motor nameplate value, static pressure may be too high and CFM may be too low. To determine the actual CFM (± 5%);

a. Measure the actual fan RPM

b. Calculate the Theoretical BHP

Actual Motor Amps

Motor Nameplate Amps

Use appropriate figures beginning with Figure 45, p. 93 to calculate a new fan drive if the CFM is not at design specifications.

8. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

X Motor HP

Traq™ Sensor Airflow Measurement (Optional with all units equipped with an economizer)

1. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the appropriate programming manual for CV or VAV applications for the SERVICE TEST screens and programming instructions.

2. Use Table 32, p. 86 to program the following system components for Economizer operation by scrolling through the displays;

Supply Fan (On)

Fresh Air dampers (Selected% Open)

Variable Frequency Drive (100% Output, if applicable)

RTM Occ/Unocc Output (Unoccupied)

Outside Air CFM Setpoint

Outside Air Pre-Heater Operation (if applicable)

3. Once the configuration for the components is complete, press the NEXT key until the LCD displays the “Start test in __Sec.” screen. Press the + key to designate the delay before the test

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Sequence of Operation

is to start. This service test will begin after the TEST START key is pressed and the delay designated in this step has elapsed. Press the ENTER key to confirm this choice.

4. Press the TEST START key to start the test. Remember that the delay designated in step 3 must elapse before the fans will begin to operate.

5. With the unit operating in the "TEST MODE", the amount of outside air flowing through the traq sensor can be viewed by switching to the "STATUS MENU" screen "OA CFM.

6. Scroll to the "ECONOMIZER ENABLE/ECONOMIZER POSITION" screen by pressing the "NEXT" key and read the corresponding damper opening percentage (%).

7. Press the STOP key at the Human Interface Module in the unit control panel to stop the unit operation.

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Performance Data

0 5000 10000 15000 20000 25000 30000 35000

0% WOCFM

2000 RPM

1900 RPM

1800 RPM

1700 RPM

BHP

5 BHP

1600 RPM

1500 RPM

1400 RPM

1300 RPM

1200 RPM

1100 RPM

1000 RPM

900 RPM

Static Presure(InWC)

0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 55000

40 B

1600 RPM

1500 RPM

BHP

25 BH

20 B

15 BH

10 BHP

.5 BH

5 BH

1400 RPM

1300 RPM

1200 RPM

1100 RPM

1000 RPM

900 RPM

800 RPM

700 RPM

Volumetric Airflow Rate(CFM)

Static Presure(InW C)

Supply Fan (with or without Variable Frequency Drive)

Figure 45. Supply fan performance STANDARD CFM — casing A, 25”

Figure 46. Supply fan performance STANDARD CFM — casing B, 32”

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Performance Data

0 5000 10000 1500 0 20000 25000 30000 350 00 40000 45000 50000 550 00

BHP

0 BHP

60%

25 BHP

20 BHP

1300 RPM

1200 RPM

1100 RPM

1000 RPM

900 RPM

800 RPM

700 RPM

600 RPM

Volumetric Airflow Rate(CFM)

Static Presure(InW C)

0 5000 10000 15000 20000 25000 30000

BHP

B H

7.5 BHP

Volumetric Airflow Rate(CFM)

25" FC Exhaust Fan Performance w/Damper

Static Presure(InWC)

Figure 47. Supply fan performance STANDARD CFM — casing C, 36”

Exhaust Fan

Figure 48. Exhaust fan performance STANDARD CFM—casing A; LOW CFM—casing B

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Performance Data

0 5000 10000 15000 20000 25000 30000 35000 40000 45000

60% W

0 B

H P

3 0

2 5

Volumetric Air flow Rate(CFM)

28" FC Exhaust Fan Performance w/Damper

Static Presure(InWC)

0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 55000

CFM

6 0

5 0

BHP

Volumetr ic Airflow Rat e(CFM)

32" FC Exhaust Fan Performance w/Damper

Static Presure(InWC)

Figure 49. Exhaust fan performance STANDARD CFM—casing B; LOW CFM—casing C

Figure 50. Exhaust fan performance standard CFM—casing C

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Performance Data

0 5000 10000 15000 20000 25000 30000 35000 40000

Volum etric A irflow R ate(C FM)

36.5" Return Fan Performance

Static Presure(InW C)

0 5000 10000 150 00 20000 25000 30000 35000 400 00 45000

0 BHP

Volumetric Airflow Rate(CFM)

40" Return Fan Performance

Static Presure(InWC)

Return Fan

Figure 51. Return fan performance STANDARD CFM—casing A

Figure 52. Return fan performance standard CFM—casing B and C

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Component Static Pressure Drops

Table 33. Chilled water coil airside pressure drop (in H20)

Airside Pressure Drop (in H2O)

2 row 4 row 6 row 8 row

108

144

Casing CFM

16000 0.03 0.06 0.09 0.12 0.09 0.13 0.19 0.25 0.13 0.19 0.29 0.36 0.18 0.27 0.39 0.49

20000 0.06 0.09 0.13 0.16 0.13 0.19 0.27 0.34 0.20 0.28 0.40 0.50 0.27 0.38 0.54 0.68

23000 0.07 0.11 0.16 0.19 0.17 0.24 0.33 0.41 0.25 0.35 0.49 0.61 0.34 0.48 0.67 0.83

A, B, C

28000 0.10 0.15 0.21 0.26 0.24 0.33 0.44 0.54 0.35 0.49 0.66 0.81 0.48 0.67 0.89 1.10

33000 0.14 0.19 0.26 0.32 0.31 0.43 0.57 0.69 0.46 0.64 0.85 1.03 0.63 0.87 1.14 1.39

38000 0.18 0.24 0.33 - 0.40 0.54 0.70 - 0.59 0.80 1.04 - 0.81 1.09 1.41 -

43000 0.22 0.29 - - 0.49 0.65 - - 0.73 0.98 - - 0.99 1.34 - -

45000 0.23 0.31 - - 0.53 0.70 - - 0.78 1.05 - - 1.07 1.44 - -

80 fpf

fpf

168

fpf 80 fpf

Table 34. Component static pressure drops (in. H2O)

108

fpf

Chilled Water Coil

144

168

fpf

fpf 80 fpf

108

fpf

144

fpf

168

fpf 80 fpf

Performance Data

108

144

fpf

168

fpf

Gas Heating

Electric Heating

(Horiz.) Low Heat

Casing CFM All kW's

16000 0.01 0.01 0.10 0.01 0.12 0.01 0.14 0.13 0.08 0.12 0.08 0.06 0.11 0.19

20000 0.02 0.01 0.16 0.01 0.19 0.01 0.22 0.17 0.11 0.16 0.11 0.09 0.15 0.26

23000 0.03 0.01 0.21 0.01 0.26 0.01 0.30 0.23 0.15 0.22 0.16 0.13 0.23 0.38

A, B, C

(i) There is no pressure drop with Electric Heat DF configuration

28000 0.04 0.02 0.31 0.02 0.38 0.02 0.44 0.32 0.21 0.31 0.22 0.20 0.34 0.57

33000 0.06 0.02 0.42 0.02 0.53 0.02 0.61 0.42 0.28 0.41 0.30 0.28 0.47 0.79

38000 0.07 0.03 0.56 0.03 0.70 0.03 0.81 0.53 0.36 0.52 0.39 0.38 0.63 1.05

43000 0.10 0.04 0.72 0.04 0.89 0.04 1.03 0.65 0.45 0.65 0.49 0.49 0.81 1.34

45000 0.10 0.04 0.79 0.04 0.98 0.04 1.13 0.71 0.49 0.70 0.53 0.53 0.89 1.47

(i)

DF Hz DF Hz DF Hz High Low High Low

Medium

Heat High Heat

Hydronic Heating Coil

Data

Hot Water

Coil Steam Coil

Return

Damper

Econo

Damper

(wide

open

in H20)

Traq

Damper

(wide

open

in H20)

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Performance Data

Table 35. Component static pressure drops (in. H2O)

Standard Filter Section (Cooling Coil) Final Filter Section (Cooling Coil)

Std 2"

High Eff

Throw

Away

Casing CFM

16000 0.08 0.24 0.27 0.34 0.23 0.36 0.29 0.35 0.54 0.48

20000 0.11 0.29 0.32 0.39 0.29 0.42 0.34 0.42 0.66 0.58

23000 0.11 0.29 0.32 0.39 0.29 0.42 0.34 0.42 0.66 0.58

A, B, C

(i) Case A, B, C Max CFM 45,000 (ii) Case A, B, C Max CFM 37,000

28000 0.18 0.49 0.49 0.56 0.51 0.61 0.54 0.68 1.01 0.88

33000 0.23 0.61 0.61 0.67 0.65 0.73 0.69 0.86 1.22 1.06

38000 0.28 0.74 0.76 0.78 0.81 0.86 0.86 1.06 - -

43000 0.33 0.89 0.92 0.91 0.98 1.00 1.05 1.30 - -

45000 0.36 0.95 0.99 0.96 1.05 1.06 1.13 1.40 - -

Filters

90-95%

Low PD

Cartridge

Filters w/

Prefilter

90-95%

Cartridge

Filters w/

Prefilter

90-95%

Filters w/

Prefilter

(i)

Bag

(i)

90-95%

Std Temp

Low PD

Cartridge

Filters w/

4”

Prefilter

(i)

90-95%

Std Temp

Bag

Filters w/

Prefilter

(i)

90-95% Std Temp Cartridge

Filters w/

Prefilter

(i)

90-95% Hi Temp

Cartridge

Filters w/

2" Hi

Temp

Prefilter

(i)

90-95% Hi Temp

HEPA w/

2" Hi

Temp

Prefilter

(ii)

90-95%

Std Temp

HEPA

Filters

w/ 2" Hi

Temp

Prefilter

(ii)

98 RT-SVX28E-EN

Page 99

Unit Start-up

Storage and Operating Temperature Limits

Storage: -40ºF to 150ºF

Operation: -40ºF to 125ºF

Economizer Damper Adjustment

Exhaust Air Dampers

Verify that the exhaust dampers (if equipped) close tightly when the unit is off. Adjust the damper linkage as necessary to ensure proper closure. An access panel is provided under each damper assembly.

Fresh Air & Return Air Damper Operation

The fresh air and return air damper linkage is accessible from the filter section of the unit. The damper linkage connecting the fresh air dampers to the return air dampers is preset from the factory in the number 1 position. Refer to Figure 53, p. 101 for the appropriate linkage position for the unit and operating airflow (CFM).

No Step Surface!

Do not walk on the sheet metal drain pan. Walking on the drain pan could cause the supporting metal to collapse, resulting in the operator/technician to fall. Failure to follow this recommendation could result in death or serious injury.

WARNING

Note: Bridging between the unit main supports may consist of multiple 2 by 12 boards or sheet

metal grating.

Arbitrarily adjusting the fresh air dampers to open fully when the return air dampers are closed or; failing to maintain the return air pressure drop with the fresh air dampers when the return air dampers are closed, can overload the supply fan motor and cause building pressurization control problems due to improper CFM being delivered to the space.

The fresh air/return air damper linkage is connected to a crank arm with a series of holes that allows the installer or operator to modify the amount of fresh air damper travel in order to match the return static pressure. Refer to Tab l e 3 6 , p . 10 3 for the equivalent return air duct losses that correspond to each of the holes illustrated in Figure 53, p. 101.

To Adjust the Fresh Air Damper Travel

1. Drill a 1/4" hole through the unit casing up stream of the return air dampers. Use a location that will produce an accurate reading with the least amount of turbulence. Several locations may be necessary, and average the reading.

Hazardous Voltage!

HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR UNIT DISCONNECT SWITCH.

2. Close the disconnect switch or circuit protector switch that provides the supply power to the unit terminal block or the unit mounted disconnect switch.

3. Turn the 115 volt control circuit switch and the 24 volt control circuit switch to the "On" position.

WARNING

RT-SVX28E-EN 99

Page 100

Unit Start-up

4. Open the Human Interface access door, located in the unit control panel, and press the SERVICE MODE key to display the first service screen. Refer to the latest edition of the applicable programming manual for CV or VAV applications for the SERVICE TEST screens and programming instructions.

5. Use Table 32, p. 86 to program the following system components for operation by scrolling through the displays;

Supply Fan (On)

Variable Frequency Drive (100% Output, if applicable)

RTM Occ/Unocc Output (Unoccupied)

Fresh Air Dampers (Closed)

6. Once the configuration for the components is complete, press the NEXT key until the LCD displays the “Start test in __Sec.” screen. Press the + key to designate the delay before the test is to start. This service test will begin after the TEST START key is pressed and the delay designated in this step has elapsed. Press the ENTER key to confirm this choice.

WARNING

Rotating Components!

The following procedure involves working with rotating components. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to disconnect power before servicing could result in rotating components cutting and slashing technician which could result in death or serious injury.

7. Press the TEST START key to start the test. Remember that the delay designated in step 6 must elapse before the fan will begin to operate.

8. With the fresh air dampers fully closed and the supply fan operating at 100% airflow requirements, measure the return static pressure at the location determined in step 1.

9. Press the STOP key at the Human Interface Module in the unit control panel to stop the fan operation.

10. Open the field supplied main power disconnect switch upstream of the air handler unit. Lock the disconnect switch in the "Open" position while working on the dampers.

11. Compare the static pressure reading to the static pressure ranges and linkage positions in

Table 36, p. 103 for the unit size and operating CFM.

To relocate the fresh air/return air connecting rod to balance the fresh air damper pressure drop against the return static pressure, use the following steps. If no adjustment is necessary, proceed to step 17.

12. Remove the drive rod and swivel from the crank arm(s). If only one hole requires changing, loosen only that end.

13. Manually open the return air dampers to the full open position.

14. Manually close the fresh air dampers.

15. Reattach the drive rod and swivel to the appropriate hole(s). The length of the drive rod may need to be adjusted to align with the new hole(s) location. If so, loosen the lock nut on the drive rod against the swivel. Turn the swivel "in" or "out" to shorten or lengthen the rod as necessary. For some holes, both ends of the rod may need to be adjusted.

16. Tighten the lock nut against the swivel(s).

17. Plug the holes after the proper CFM has been established.

100 RT-SVX28E-EN

Trane WEHC, WSHC, WFHC, WXHC, WLHC Installation and Maintenance Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Overview of Manual

Table of Contents

Model Number Descriptions

General Information

Dimensional Data

Pre-Installation

Installation

Unit Weights

Roof Curb and Ductwork

Pitch Pocket Location

Field Converting Horizontal Ductwork from Right to the Left Side

Unit Rigging and Placement

Lifting the External Piping Enclosure

Gas Heat Units

Connecting the Gas Supply Line to the Furnace Gas train

Flue Assembly Installation

Hot Water Heat Units

Steam Heat Units

General Coil Piping and Connection Recommendations

Chilled Water Units

Electrical Data

Disconnect Switch w/External Handle

Electric Heat Units

Main Unit Power Wiring

Power Wire Sizing and Protection Devices

Controls

Sequence of Operation

Gas Heating Sequence of Operation

Electric Heat Sequence of Operation

System Airflow Measurements

Exhaust Airflow Measurement (Optional)

Performance Data

Supply Fan (with or without Variable Frequency Drive)

Exhaust Fan

Return Fan

Component Static Pressure Drops

Unit Start-up

Economizer Damper Adjustment