Energy Tech Laboratories DHG180, DHG240 User Manual

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Page 1

INSTALLATION INSTRUCTION

CONTENTS

GENERAL.................................3

SAFETYCONSIDERATIONS..................3

AGENCYAPPROVALS ......................4

INSPECTION...............................4

INSTALLATION ............................4

OPERATION..............................19

MAINTENANCE ...........................25

COMPLETE TABLE OF CONTENTS ONFOLLOWING PAGE

SUNLINE GAS/ELECTRIC

SINGLE PACKAGE

AIR CONDITIONERS

SAVE THIS MANUAL

MODELS: DHG180 (15 TON, 10.0 EER)

DHG240 (20 TON, 9.7 EER)

208/230/460 VOLT

MODELS ONLY

208/230/575 VOLT

MODELS ONLY

035-17233-000-C-0702

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TABLE OF CONTENTS

035-17233-000-C-0702

GENERAL ......................................3

SAFETYCONSIDERATIONS .......................3

REFERENCE ........................................4

RENEWALPARTS .........................................4

AGENCY APPROVALS . . . . . . . . . . . . . . . . . . . . . . .. . . . . 4

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

INSTALLATION..................................4

LIMITATIONS........................................4

LOCATION ..........................................5

RIGGING AND HANDLING .............................5

CLEARANCES .......................................5

DUCTWORK .........................................6

FIXEDOUTDOORAIRINTAKEDAMPER..................6

CONDENSATEDRAIN.................................7

COMPRESSORS .....................................7

FILTERS ............................................7

SERVICEACCESS ...................................7

THERMOSTAT.......................................7

POWERANDCONTROLWIRING........................7

COMBUSTIONDISCHARGE............................8

GASPIPING.........................................8

GASCONNECTION ...................................8

L.P.UNITS,TANKSANDPIPING .......................10

VENTANDCOMBUSTIONAIRHOODS..................11

OPTECONO/MOTORIZEDDAMPERRAINHOOD .........11

ENTHALPYSETPOINTADJUSTMENT ........................11

PWREXH/BARORELIEFDMPR&RAINHOODOPT .......11

OPERATION ...................................19

COOLINGSYSTEM ..................................19

PRELIMINARYOPERATIONCOOLING ..................19

COOLINGSEQUENCEOFOPERATION .................19

NOOUTDOORAIROPTIONS ...............................19

ECONOMIZER WITH SINGLE ENTHALPY SENSOR . . .. . . . .. . .. . 19

ECONOMIZERWITHDUALENTHALPYSENSORS ..............19

ECONOMIZERWITHPOWEREXHAUST ......................19

MOTORIZEDOUTDOORAIRDAMPERS ......................19

CONTINUOUSBLOWER ...................................19

SAFETYCONTROLS.................................19

HEATINGSYSTEM ..................................20

CONTINUOUSBLOWER ...................................20

INTERMITTENTBLOWER ..................................20

SAFETYCONTROLS.................................20

HEATANTICIPATORSETPOINTS ......................21

STARTUP.....................................21

PRE-STARTCHECKLIST .............................21

OPERATING INSTRUCTIONS ..........................21

TO LIGHT PILOT AND MAIN BURNERS: . . . . . . . . . . .. . .. . . .. . . . . 21

TOSHUTDOWN ..........................................22

POST-STARTCHECKLIST(GAS) ......................22

MANIFOLDGASPRESSUREADJUSTMENT..............22

PILOTCHECKOUT ..................................22

BURNERINSTRUCTIONS.............................22

BURNERAIRSHUTTERADJUSTMENT..................23

CHECKINGSUPPLYAIRCFM .........................23

ADJUSTMENTOFTEMPERATURERISE ................24

BELTDRIVEBLOWER .....................................24

CHECKINGGASINPUT ..............................24

NATURALGAS ...........................................24

SECURE OWNER’SAPPROVAL ........................24

MAINTENANCE.................................25

NORMALMAINTENANCE .............................25

FILTERS ................................................ 25

MOTORS................................................ 25

OUTDOORCOIL .......................................... 25

BURNER & PILOT . .. . . . . . . . . .. . . . . . . . . . . . . . . .. . .. . . . . . . . . . 25

TO CLEAN BURNERS . . . . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . . . . 25

COMBUSTIONAIRDISCHARGE .............................25

CLEANINGFLUE&HEATINGELEMENTS ................25

TROUBLESHOOTING ...........................26

LIST OF FIGURES

Fig. # Pg. #

1 TYPICALRIGGING............................5

2 CENTEROFGRAVITY.........................5

3 FIXEDOUTDOORAIRDAMPER.................6

4 RECOMMENDEDDRAINPIPING ................7

5 TYPICALFIELDWIRING .......................9

6 EXT SUPPLY CONN EXT SHUT-OFF . . . . . . . . . . . . 10

7 BOTTOMSUPPLYCONNEXTSHUT-OFF........10

8 VENTANDCOMBUSTIONAIRHOODS ..........11

9 ENTHALPYSETPOINTADJUSTMENT ...........12

10 UNITDIMENSIONSFRONTVIEW...............14

11 UNITDIMENSIONSRAINHOOD ................14

12 UNITDIMENSIONSREARVIEW................15

13 208 VOLT & HIGH SPEED DRIVEACCY . . . . . . .. . 16

14 GASVALVEPIPING..........................20

15 GASVALVEANDCONTROLS..................21

16 TYPICALGASVALVE ........................22

17 PROPERFLAMEADJUSTMENT ................22

18 TYPICAL FLAME APPEARANCE . . . . . . . . . . . . . . . . 23

19 BELTADJUSTMENT .........................23

20 PRESSUREDROP ...........................24

21 TYPICALFLUEBAFFLEINSTALLATION .........26

LIST OF TABLES

Tbl. # Pg. #

1 PRODUCT NOMENCLATURE . . . . . . . . . . . . . . . . . . . . 3

2 UNIT APPLICATION DATA . . . . . . . . . . . . . . . . . . . . . . 4

3 CONTROLWIRESIZES.........................8

4 GAS HEAT APPLICATION DATA . . . . . . . .. . . . . . . .. 9

5 PIPESIZING.................................10

6 PHYSICALDATA .............................13

7 DHGVOLTAGELIMITATIONS ..................13

8 MINIMUMCLEARANCES ......................13

9 DHGELECTRICALDATA ......................13

10UTILITIESENTRY ............................15

11DHG 15T SUPPLY AIR BLOWER PERFORMANCE . . 16 12DHG 20T SUPPLY AIR BLOWER PERFORMANCE . . 17

13STATICRESISTANCES........................18

14POWER EXHAUST PERFORMANCE . . . . . . . . . . . . . 18

15BLOWERMOTORANDDRIVEDATA.............18

16LIMITCONTROLSETTING .....................21

17HEATANTICIPATORSETPOINT ................21

18GASRATE-CUBICFEETPERHOUR............24

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TABLE 1: PRODUCT NOMENCLATURE

Model #

1 HG 180

018

Model Number

Description

Product Category

Product Generation

Product Identifier

Nominal Cooling Capacity

Factory Installed Heat

Nominal Heating Capacity

Voltage Code

Factory Installed

Option Code

D 1 HG 180 E 180 25 EC

Options

D =Air Cond., Single Package 1 =1st Generation HG =Gas/Electric 180 =15 Tons 240 = 20 Tons

A = No Heat E = Electric Heat

018 =18 kW 054 = 54 kW 036 =36 kW 072 = 72 kW 25 =208/230-3-60

58 =575-3-60 EC = Single Input Economizer DK = Dual Input Economizer FD = Sing. Input Economizer w/ Power

Exhaust BG =Motorized Outdoor Air Damper

N=NaturalGas

46 = 460-3-60

CF = Dual Input Economizer with Power Exhaust

GENERAL

YORK Model DHG units are single package high efficiency gas-fired central heating furnaces with cooling unit designed for outdoor installation on a rooftop or a slab.

The units are completely assembled on rigid, permanently attached base rails. All piping, refrigerant charge, and electrical wiring is factory installed and tested. The units require electric power, gas connection, duct connections, installation of combustion air inlet hood, flue gas outlet hoods and fixed outdoor air intake damper (units without economizer or motorized damper option only) at the point of installation.

The gas-fired heaters have aluminized-steel tubular heat exchangers and spark ignition with provenpilot.

FOR YOUR SAFETY IF YOU SMELL GAS: a. Open windows.

b. Don’t touch electrical switches; do not use any

phones inthe area ofthe gas leak.

SAFETY CONSIDERATIONS

Installer should pay particular attention to the words: NOTE, CAUTION, and WARNING. Notes are intended to clarify or make the installation easier. Cautions are given to prevent equipment damage. Warnings are given to alert installer that personal injury and/or equipment damage may result if installation procedure is not handled properly.

Due to system pressure, moving parts and electrical components, installation and servicing of air conditioning equipment can be hazardous. Only qualified, trained, service personnel should install, repair, maintain or service this equipment.

Observe all precautions in the literature, on labels and tags accompanyingthe equipment whenever working on air conditioning equipment. Be sure to follow all other safety precautions thatapply.

Wear safety glasses and work gloves, and follow all safety codes. Use a quenching cloth and have a fire extinguisher available for all brazing operations.

c. Extinguish any open flame. d. Immediately call your gas supplier from another

location. Follow your gas supplier’s instructions.

e. If you cannot reachyour gas supplier, call the fire

departments.

This product must be installed in strict compliance with the enclosed installation instructions and any applicable local, state, and national codes including, butnot limited to, building, electrical and mechanical codes.

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INSTALLATION

LIMITATIONS

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Improper installation may create a condition where the operation of the product could causepersonal injury orproperty damage.

REFERENCE

Additional information on the design, installation, operation and service of this equipment is available in the following reference forms:

• 44-320-10 - Barometric Relief Damper Accessory

• 530.18-N6.1V - Propane Conversion Accessory(USA)

• 530.18-N6.2V - High Altitude Accessory (Nat. Gas)

• 530.18-N6.3V - High Altitude Accessory (Propane)

RENEWAL PARTS:

Refer to the Renewal Parts Manual for complete listing of replacement parts on this equipment.

All forms referenced in this instruction may be ordered from:

Standard Re gister 2101 West Tecumseh Road Norman, Oklahoma 73069 Toll Free Phone (877) 318-9675 Toll Free Fax: (877) 379-7920

AGENCY APPROVALS

Design certified by ETL as follows:

These units must be installed in accordance with the following national and local safety codes:

1. National Electrical Code ANSI/NFPA No. 70.

2. NationalFuel Gas Code Z223.1.

3. Gas-Fired Central Furnace StandardANSI Z21.47a.

4. Local gas utility requirements. Refer to Table 2 for Unit Application Data and to Table 4 for

Gas HeatApplication Data.

TABLE 2: UNIT APPLICATION DATA

MODEL SIZE 15 TON 20 TON

VoltageVariation,

Min./Max

Supply Air CFM, Min./Max. 4500/7200 6000/9400

Wet Bulb Temperature (°F) of a ir

on Outdoor CoilMin./Max.

Dry Bulb Temperature (°F) of air

on Outdoor CoilMin./Max.

Rated in accordance with ARI Standard110, utilization range “A”.

A lowambient accessory is available for operation downto0°F.

208/230-3-60 187/253

460-3-60 414/506 575-3-60 518/630

57/72

25/120

1. For use as a forced air furnace with cooling unit.

2. For outdoor installationonly.

3. For installation on combustible material.

4. For use with natural gas or propane gas.

After installation, the unit must be adjusted to obtain a temperature rise within the range specified on the unit rating plate.

If components are to be added to a unit to meet local codes, they are to be installed at the dealer's and/or the customer's expense.

INSPECTION

As soon as a unit is received,it shouldbe inspected for possible damage during transit. If damage is evident, the extent of the damage should be noted on the carrier's freight bill. A separate request for inspection by the carrier's agent should be made in writing. Refer to Form 50.15-NM for additional information.

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Size ofunit for proposed installation should be based on heat loss/heat gain calculation made according to the methods of the Air Conditioning Contractorsof America (ACCA).

This furnace is not to be used for temporary heating of buildings orstructures under construction.

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LOCATION

Use the following guidelines to select a suitable location for these units.

1. Unit is designed for outdoor installation only.

2. Condensercoils must have an unlimited supply of air. Where a choice of location is possible, position the unit

on eithernorth or eastside of building.

Excessive exposure of this furnace to contaminated combustion air may result equipment damage or personal injury. Typical contaminates include: permanent wave solutions, chlorinated waxes and cleaners, chlorine based swimming pool chemicals, water softening chemicals, carbon tetrachloride, Halogen type refrigerants, cleaning solvents (e.g. perchloroethylene), printing inks, paint removers, varnishes, hydrochloric acid, cements and glues, antistatic fabric softeners for clothes dryers, masonry acid washing materials.

Length ofthe forks must be a minimum of 90”.

An adhesive backed label isprovided overthe outside of the combustion air inlet opening to prevent moisture from entering the unit which could cause damage to electrical components. Allow this closure label to remain in place until the combustion air hoodis to be installed (refer to Figure 7).

3. For ground level installation, use a level concrete slab with a minimum thickness of 4 inches.The length and width should be at least 6 inchesgreater than the unit base rails. Do not tie slabto the building foundation.

4. Roofstructures must beable to support the weightof the unit andits options and/or accessories.Unit must be installed on a solid level roof curb or appropriate angle

iron frame.

Ifaunitistobeinstalledonaroofcurborspecial frame other than a YORK roof curb, gasketing must be applied to all surfaces that come in contact with the unit underside.

5. Maintain leveltolerance to 1/2" maximum across the entire length or width of the unit.

RIGGING AND HANDLING

Exercise care when moving the unit. Do not remove any packaging until the unit is near the place of installation. Rig the unit by attaching chain or cable slings to the round lifting holes provided in the base rails. Spreaders, whose length exceeds the largest dimension across the unit, MUST be used across the top of the unit. Refer to Figure 1.

FIGURE 1: TYPICAL RIGGING

Refer to Table 6 for unit weights and to Figure 2 for approximate center of gravity.

FIGURE 2 : CENTER OF GRAVITY

CLEARANCES

Units may also be moved or lifted with a forklift, from the front or rear only, providing that an accessory skidis used.

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All units require certain clearances for proper operation and service. Installer must make provisions for adequate

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combustion and ventilation air in accordance with Section

5.3, Air for Combustion and Ventilation of the National Fuel Gas Code, ANSI Z223.1 (in U.S.A.) or Sections 7.2, 7.3 or

7.4 of Gas Installation Codes CAN/CGA-B149.1 and .2 (in Canada) and/or applicable provisions of the local building codes. Refer to Table 8 for the clearances required for combustible construction, servicing, and proper unit

operation.

Do not permit overhanging structures or shrubs to obstruct outdoor air discharge outlet, combustion air inlet or vent outlets.

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DUCTWORK

Ductwork should be designed and sized according to the methods in Manual Q of the Air Conditioning Contractors of America (ACCA).

A closedreturn duct system shall be used. This shall not preclude use of economizers or outdoor fresh air intake. The supply and return air duct connections at the unit should be made with flexible joints to minimize noise.

The supply and return air duct s ystems should be designed for the CFM and static requirements of the job. They should NOT be sized to match the dimensions of the duct connec-

tions on the unit.

When fastening ductwork to side duct flanges on unit, insert screws through duct flanges only. DO NOT insert screwsthrough casing.

Outdoor ductwork must be insulated and waterproofed.

Refer to Figure 10 and12 for information concerning side and bottom supply and return air duct openings.

FIGURE 3 : FIXED OUTDOOR AIR DAMPER

Gasketing and mounting screws are provided in a parts bag attached to the hood assembly. Apply gasketing to the three flange surfaces on the hood prior to installing the hood. Extend gasketing 1/4" beyond the top and bottom of the two side flanges to insure adequate sealing.

Adjusting the damper to the desired air flow may be done before mounting the hood into position or (after installation) by removing thefront hood panel or thescreen on the bottom of the hood. Damper baffle in position 1 will allow approximately 10% recirculated air flow, position 2 approximately 15% and, to allow approximately 25%, remove the damper baffle.

On units with bottom return air applications, install the damper assembly over the opening in the side return air access panel. Remove and discard the opening cover and the covering over the hood mounting holes (used for shipping) before installing. Securewith the screws provided.

On units with side return air applications, install the damper assembly on the return air ductwork as close to the unit as possible.Cut anopening 16" high by 18" wide in the ductwork to accommodate the damper. Using the holes in the hood flanges as a template, drill 9/64" dia. (#26 drill) holes into the

ductwork and secure with the screws provided.

FIXED OUTDOOR AIR INTAKE DAMPER

This damper is shipped inside the return air compartment. It is completely assembled and ready for installation. A damper baffle inside of the hood is adjustable to provide variable amounts of outdoor air intake on units that are not provided with an economizer or a motorized damper option. Refer to Figure 3.

6 Unitary Products

If outdoor air intake will not be required on units with bottom return air applications, the damper assembly should still be mounted on the side return airaccess panel, per theinstructions above, to insure moisture is not drawn into the unit during operation. The covering over the mounting holes only need be removed. Do not remove theopening cover.

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035-17233-000-C-0702

CONDENSATE DRAIN

Plumbing must conform to local codes. Use a sealing compound on male pipe threads. Install a condensate drain line from the 1" NPT female connection on the unit to an open

drain.

FIGURE 4 : RECOMMENDED DRAIN PIPING

An alternate drain connection (1" NPT female coupling) is provided inboard on the same centerline as the exterior location.

NOTE:

vide proper drainage.See Figure 4.

The condensate drain line MUST be trapped to pro-

• Side Supply & Return Air compartments (Two panels)

• Blower compartment (Three panels)

• Main control box

• Filter compartment

• Outdoor Air compartment (Two panels)

Refer toFigure 10 forlocation of these access panels.

Make sure that all screws and panel latches are replaced and properly positioned on the unit to maintain an air-tight seal.

THERMOSTAT

The room thermostat should be located on an inside wall approximately 56" above the floor where it will not be subject to drafts, sun exposure or heat from electrical fixtures or appliances. Follow manufacturer's instructions enclosed with thermostat for general installation procedure. Seven color coded insulated wires (#18 AWG) should be used to connect thermostat to unit.

POWER AND CONTROL WIRING

COMPRESSORS

Units are shipped with compressor mountings factoryadjusted and ready for operation.

Do Not loosen compressor mountingbolts.

FILTERS

Two-inch filters are supplied with each unit. Filters must always be installed ahead of the evaporator coil and must be keptcleanorreplacedwithsamesizeandtype.Dirtyfilters will reduce the capacity of the unit and will result in frosted coils or safety shutdown. Minimum filter area and required sizes areshown in Table 6.

SERVICE ACCESS

Access to all serviceable components areprovided bythe following removable panels:

• Compressor compartment

• Gas Heatcompartment (Two panels)

Field wiring to the unit must conform to provisions of the National Electrical Code, ANSI / NFPA No. 70 (latest edition) and/or local ordinances. The unit must be electrically grounded in accordance with N.E.C. and/or local codes. Voltage tolerances which must be maintained at the compressor terminals during starting and running conditions are indicated on the unit Rating Plate and Table 2.

The internal wiring harness furnished with this unit is an integral part of a ETL design certifiedunit. Field alterationto comply withelectrical codesshould not be required.

A fused disconnect switch should be field provided for the unit. Theswitch must be separate from all othercircuits. Wire entry at knockout openings require conduit fittings to comply with NEC and/or local codes. Refer to Figure 10 for installation location. If any of the wire supplied with the unit must be replaced, replacement wire must be of the type shown on the wiring diagram and the same minimum gauge as the replaced wire.

Electrical line must be sized properly to carry the load. Each unit must be wired with a separate branch circuit fed directly

from themeter panel and properly fused.

Refer toFigure 5 for typical field wiringand to the appropriate unit wiring diagram for control circuit and power wiring information.

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035-17233-000-C-0702

Typical supply piping arrangements are shown in Figures 6 and 7. All shaded items are field-supplied.

When connecting electrical power and control wiring to the unit, waterproof type connectors MUST BE USED so that water or moisture cannot be drawn into the unit during normal operation. The above waterproofing conditions will also apply when installing a field-supplied disconnect switch.

COMBUSTION DISCHARGE

The products of combustion are discharged horizontally through two screened (hooded) openings on the upper gas

heat access panel.

TABLE 3: CONTROL WIRE SIZES

Wire Size

22 20 19 18 16 40 120 150 190 305

Max. Wire Length3Feet

Total wire length is from unit to room thermostat, and back tounit.

Solid, ClassII copper wire.

Total Wire length is from unitto room thermostat, and back tounit.

GAS PIPING

Proper sizing of gas piping depends on the cubic feet per hour of gas flow required, specific gravity of the gas and the length of run. National Fuel Gas Code Z223.1 should be followed in all cases unless superseded by local codes or gas utility requirements. Refer to Table 5.

The heating value of the gas may differ with locality. The value should be checked with the local gas utility.

NOTE:

There may be a local gas utility requirement specify-

ing a minimum diameter for gas piping. All units require a 1 inch pipeconnection at the entrance fitting.

GAS CONNECTION

The gas supply line can be routed through the knockouts located on the front of the unit or through the opening providedintheunit'sbase.RefertoFigure10tolocatethese access openings.

Two grommets are shipped in the blower compartment (in parts bag taped to the blower housing) of every unit with gas heat and should be used in the knockouts when the gas piping penetrates the front of the unit.

After the gas supply piping has been installed, the bottom opening in the unit should be sealed to prevent water from leaking into the building.

Gas piping recommendations:

1. A drip leg and a ground joint union must be installed in the gaspiping.

2. When required by localcodes, a manual shut-off valve may haveto be installed outside of the unit.

3. Usewrought iron orsteel pipe forall gas lines.Pipe dope should be applied sparingly tomale threads only.

4. All piping shouldbe cleaned of dirt and scale by hammering on the outside of the pipe and blowing out the loose dirtand scale. Before initial start-up, besure that all ofthe gas lines external tothe unit have been purged of air.

5. Thegas supply should be aseparate line andinstalled in accordance with all safety codes as prescribed under Limitations.After the gas connections have been completed, open the main shut-off valve admitting normal gas pressure tothe mains.Check alljoints forleaks with soap solution orother material suitable for the purpose. NEVER USE AFLAME.

6. Thefurnace and its individual manual shut-off valve must be disconnected fromthe gas supply pipingsystem during anypressure testingof that system at test pressures in excessof 1/2 psig (3.48kPa).

The furnace mustbe isolatedfrom the gas supply piping system byclosing itsindividual manual shut-off valve during anypressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.48kPa).

7. A1/8 inchNPTplugged tapping, accessiblefor testgage connection, must be installed immediately upstream of the gassupply connection to the furnace.

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035-17233-000-C-0702

C O O L I N G O N L Y ( 2 4 V O L T T H E R M O S T A T )

T H E R M O S T A T

T E R M I N A L S

Y 1

Y 2

2 4 V o l t T h e r m o s t a t 2 T H 0 4 7 0 1 2 2 4 o r 2 T H 0 4 7 0 1 5 2 4 ( w i t h S u b b a s e 2 T B 0 4 7 0 0 2 2 4 ) . T e r m i n a l b l o c k 1 T B - l o c a t e d o n r e l a y b o a r d i n 2 4 - v o l t s e c t i o n o f t h e u n i t c o n t r o l b o x .

T H E R M O S T A T

T E R M I N A L S

A D D J U M P E R

L E D 1 L E D 2

C O M

A D D J U M P E R

E l e c t r o n i c p r o g r a m m a b l e t h e r m o s t a t 2 E T 0 4 7 0 0 2 2 4 ( i n c l u d e s s u b b a s e ) .

T e r m i n a l b l o c k 1 T B - l o c a t e d o n r e l a y b o a r d i n 2 4 - v o l t s e c t i o n o f t h e u n i t c o n t r o l b o x .

S e c o n d s t a g e h e a t i n g i s n o t r e q u i r e d o n u n i t s w i t h a s i n g l e s t a g e e l e c t r i c h e a t e r .

T e r m i n a l s A 1 a n d A 2 p r o v i d e a r e l a y o u t p u t t o c l o s e t h e o u t d o o r e c o n o m i z e r d a m p e r s w h e n t h e t h e r m o s t a t s w i t c h e s t o t h e s e t - b a c k p o s i t i o n .

N O T E : F a n s s w i t c h m u s t b e i n " O N "

C O N T R O L W I R I N G

U N I T T E R M I N A L

C O O L I N G O N L Y ( 2 4 V O L T T H E R M O S T A T )

B L O C K 1 T B

R C R H

Y 1

Y 2

W 1 W 2

G B

N O T U S E D

A 1 A 2

T O R E M O T E S E N S O R 2 T H 0 4 7 0 2 2 2 4 I F U S E D

o s i t i o n f o r m i n i m u m v e n t i l a t i o n d u r i ng h e a t e r ope r a t i o n .

R Y 1 Y 2

W 1 W 2

2 4 V O L T

T R A N S F O R M E R

A 1

A 2

U N I T T E R M I N A L

B L O C K 1 T B

Y 1 Y 2

W 1

W 2

B X

2 4 V O L T

A 1

T R A N S F O R M E R

A 2

A D D J U M P E R

C O O L I N G / H E A T I N G ( 2 4 V O L T T H E R M O S T A T )

T H E R M O S T A T

T E R M I N A L S

R H

R C

Y 1

Y 2

W 1

W 2

U N I T T E R M I N A L

B L O C K 1 T B

Y 1

Y 2 W 1

W 2

A 1

A 2

2 4 V O L T T R A N S F O R M E R

Y 3

2 4 V o l t T h e r m o s t a t 2 T H 0 4 7 0 1 0 2 4 o r 2 T H 0 4 7 0 1 5 2 4

( w i t h S u b b a s e 2 T B 0 4 7 0 0 3 2 4 ) .

T e r m i n a l s t r i p 1 T B - l o c a t e d o n r e l a y b o a r d i n 2 4 - v o l t s e c t i o n

o f t h e u n i t c o n t r o l b o x .

S e c o n d s t a g e h e a t i n g i s n o t r e q u i r e d o n u n i t s w i t h a s i n g l e s t a g e

e l e c t r i c h e a t e r .

P O W E R W I R I N G

L I N E V O L T A G E T E R M I N A L B L O C K 2 T B I N C O N T R O L B O X

G R O U N D L U G

L 1

L 2 L 3

R e f e r t o t h e E L E C T R I C A L D A T A t a b l e s t o s i z e t h e p o w e r w i r i n g , t h e f u s e s a n d t h e d i s c o n n e c t s w i t c h .

FIGURE 5 : TYPICAL FIELD WIRING

TABLE 4: GAS HEAT APPLICATION DATA

Input Capacity (Mbh) Output Capacity (Mbh)

0to2000Feet

Above S ea Level

Min. Max. Min. Max. Min. Max. Min. Max.

300 150 270 135 240 213 15 & 20 Ton 279 20 50 400 200 360 180 320 281 15 & 20 Ton 372 30 60

Heaters are shipped available fro natural gas, but can be converted to L.P./Propane withKit Model No. 1NP0418.

Based on maximum input and 1075/Btu/Ft.

The airflow must be adjusted to obtain a temperature rise within the range shown.

MBH rating should be reduced at the rate of 4 percent for each 1,000 feet above 4,500 feet.

Unitary Products 9

2,000 to 4,500 Feet

Above Sea Level

0to2000Feet

Above S ea Level

2,000 to 4,500Feet

Above Sea Level

Available on

Models

Gas Rate

(Ft.3/Hr.)

Temp Rise °F

At Full Input

Page 10

035-17233-000-C-0702

TABLE 5: PIPE SIZING

Length in Feet

10 520 1,050 20 350 730 30 285 590 40 245 500 50 215 440 60 195 400 70 180 370 80 170 350 90 160 320

100 150 305

Maximum capacity of pipein cubic feet ofgas per hour. (Based upon a pressure drop of 0.3 inch water column and 0.6 specificgravity gas.)

Nominal Iron Pipe Size

1in. 1-1/4in.

FIGURE 7 : BOTTOM SUPPLY CONNECTION

EXTERNAL SHUT-OFF

L.P. UNITS, TANKS AND PIPING

All gas heat units are shipped from the factory equipped for natural gas use only. The unit may be converted in the field for use with L.P./propane gas with accessory kit model number 1NP0437.

FIGURE 6 : EXTERNAL SUPPLY CONNECTION

EXTERNAL SHUT-OFF

Natural gas may contain some propane. Propane, being an excellentsolvent, willquickly dissolve white leador most standard commercial compounds. Therefore, aspecial pipe compoundmust be applied when wroughtironor steel pipe isused. Shellac base compounds such as Gaskolacor Stalastic, and compounds such as Rectorseal #5, Cyde's or John Crane maybe used.

All L.P./propane gas equipment must conform to the safety standards of the National Fire Protection Association.

For satisfactory operation, L.P./propane gas pressure must be 8.8inch W.C atthe unit under full load. Maintaining proper gas pressure depends on three main factors:

1. The vaporization ratewhich depends on(a) thetemperature of the liquid and (b) the wetted surface area of the container or containers.

2. The proper pressure regulation. (Two-stage regulation is recommended from the standpoint of both cost and efficiency.)

3. The pressure drop in the linesbetween regulators and between the second stage regulatorand the appliance. Pipe size required will depend on the length of the pipe run and the total load of all appliances.

Complete information regarding tank sizing for vaporization, recommended regulator settings, and pipe sizing is available from most regulator manufacturers and L.P./propane gas suppliers.

L.P./propane gas is an excellent solvent and special pipe compound must be usedwhen assemblingpiping for this gas as it will quickly dissolve white lead or most standard commercial compounds. Shellac base compounds such as Rectorseal #5 are satisfactory for this typeof gas.

10 Unitary Products

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035-17233-000-C-0702

Check all connections for leaks when piping is completed, using a soap solution. NEVER USE A FLAME.

VENT AND COMBUSTION AIR HOODS

Two vent hoods and a combustion air hood (with screens) are shipped attached to the blower housing in the blower compartment. These hoods must be installed to assure proper unit function. Allhoods must be fastened to the outside of the gas heat access panel with the screws provided in the bag also attached tothe blower housing.

The screen for the combustion air intake hood is secured as shown on the label attached to the hood. The top flange of this hood slips in under the top of the access panel opening when installing. Refer to Figure 8.

Each vent hood is installed by inserting the top flange of the hood into the slotted opening in the access panel and securing in place.

SLOTTED

VENT AIR OUTLET HOODS

OPENINGS IN ACCESS PANEL

The outdoor and return air dampers, the damper actuator, the damper linkage, the outdoor and return air divider baffles, and all the control sensors are factory mounted as part of the Factory installed economizer option.

ENTHALPY SET POINT ADJUSTMENT

Remove the economizer access panel from the unit to check the following adjustments. Loosen but do not remove the two

panel latches.

Extreme care must be exercised in turning both the setpoint and minimum position adjusting screws to prevent twisting them off.

1. The enthalpy set pointmay now be set by selecting the desired s etpoint shown in Figure 9. Adjust as follows:

• For a single enthalpy operation, carefully turn the set point adjusting screw to the A, B, C or D setting corresponding to the lettered curve.

• For a dual enthalpy operation,carefully turn the set point adjusting screw fully clockwise past the D setting.

2. To check that thedamper blades move smoothly without binding, carefully turn theminimum positionadjusting screw fully clockwise and then energize andde-energize terminals R to G. With terminals Rto G energized,turn the minimum positionscrew counterclockwise untilthe desired minimum position has been attained.

3. Replacethe economizer access panel. Reposition the two latches horizontally and retighten the screws.

COMBUSTION

IR INTAKE

HOOD

GAS HEAT ACCESS PANELS

POWER EXHAUST/BAROMETRIC RE LIEF DAMPER AND RAIN HOOD OPTION

The instructions for the power exhaust/barometric relief damper and rain hood can be found in form 44-320-10. The exhaust fan, all supporting brackets, angles, and the wiring

FIGURE 8 : VENT AND COMBUSTION AIR

HOODS

are factory installed as part of thepower exhaust option. All of the components, including the dampers, hardware, and

mounting instructions are shipped in a single package exter-

OPTIONAL ECONOMIZER/MOTORIZED DAMPER RAIN HOOD

The instruction for the optional economizer/motorized

nal from the unit. The hood must be field assembled and installed.

Power exhaust is not available as a field installed option. damper rain hood can be found in form 44-320-2. Use these instructions when field assembling an economizer rain hood onto a unit.

Unitary Products 11

Page 12

035-17233-000-C-0702

FIGURE 9 : ENTHALPY SETPOINT ADJUSTMENT

12 Unitary Products

Page 13

035-17233-000-C-0702

TABLE 6: PHYSICAL DATA

MODELS

EVAPORATOR

BLOWER

EVAPORATOR

COIL

CONDENSER

FANS

(Two Per Unit)

CONDENSER

COILS

(Two Per Unit)

COMPRESSOR

(Qty.Per Unit)

AIR

FILTERS

CHARGE

BASIC

UNIT

OPTIONS

ACCY.

This compressor will be energized first.

Centrifugal Blower (Dia. x Wd. in.)

Fan Motor HP

Rows Deep

Fins Per Inch

Face Area (Sq. Ft.

Propeller Dia. (in.)(Each)

Fan Motor Hp (Each)

Nom. CFM (Each)

Rows Deep (Each)

Fins PerInch (Each)

Face Area (Sq.Ft.) (Total)

10-Ton Tandem Hermetic Recip.

5-Ton Hermetic Recip. Quantity Per Unit (16” X 20” X 2”) Quantity Per Unit (16” X 25” X 2”) Quantity Per Unit (18” X 24” X 2”)

TotalFaceArea(sq.ft.)

Refrigerant 22

(lbs./oz.)

DHG

(Gas/Electric)

Economizer (lbs) 160 Economizer with

Power E xhaust (lbs)

Motorized Damper (lbs) 150

Roof Curb (lbs) 175 185

Barometric Damper (lbs) 45 45

Wood Skid (lbs) 220 220

DHG

180 240

15 x 15 18 x15

57.5 44

13.5 13.5

15.5 20.0 30 30

5765 7000

13 15

36.0 43.3

-4

-4 5-

15.0 20.0

System #1

System #2 240Mbh (lbs) 2100 2300 320Mbh (lbs) 2140 2340

29/9 23 14/8 23/12

245

TABLE 7: DHG VOLTAGE LIMITATIONS

POWER SUPPLY

208/230-3-60

460-3-60 575-3-60

Utilization Range “A” in accordance with ARI Standard

MIN. MAX.

187 253 414 506 518 506

110.

VOLTAGE

TABLE 8: MINIMUM CLEARANCES

LOCATION CLEARANCE

Front

Back

Left Side (Filter Access)

Right Side (Cond. Coil)

Below Unit

Above Unit

Units may be installed on combustible floors made

from woodor class A, B, or C roof covering material.

Units must be installedoutdoors. Overhanging structures orshrubs should not obstruct condenser air discharge outlet.

24” (Less Economizer)

49” (With Economizer

24” (Less Economizer) 36” (With Economizer)

72” With 36”Maximum

Horizontal Overhang (For

Condenser Air Discharge)

36”

0”

TABLE 9: DHG ELECTRICAL DATA

COMPRESSORS COND. FAN

MODEL

DHG180

DHG240

POWER SUPPLY

208/230-3-60 28.6 274 14.3 137 1 4.1/4.2 5 11.8 77.8/77.0 90 4

460-3-60 14.4 138 7.2 69 1 2.1 5 5.9 42.7 50 8 575-3-60 11.4 116 5.7 58 1 1.4 5 5.2 30.7 35 8

208/230-3-60 28.6 274 28.6 274 1 4.1/4.2 7.5 18.6 98.6/96.8 110 3

460-3-60 14.4 138 14.4 138 1 2.1 7.5 9.3 52.2 60 6 575-3-60 11.4 116 11.4 116 1 1.4 7.5 7.5 40.2 45 8

Although these sizes are based on copper conductors aluminum wire can be used. Refer to the national electriccode (inUSA) or

#1 #2

RLA LRA RLA LRA

MOTORS (#1 & #2)

(ea.)

FLA (ea.)

the currentCanadian Electrical Code (in Canada) to determine the proper size.

Unitary Products 13

SUPPLY AIR

BLOWER

MOTOR

HP FLA

MIN.

CIRCUIT

AMPACITY

(AMPS)

MAX. TIME

DELAYFUSE

SIZE (AMPS)

MIN.

WIRE

SIZE 75°C

Page 14

035-17233-000-C-0702

BLOWER

BLOWER MOTOR ACCESS

BLOWER COMPARTMENT ACCESS (Auxiliary)

DOT PLUG (For pressure Drop Reading)

GAS HEAT ACCESS

VENT AIR OUTLET HOODS

COMBUSTION AIR INLET HOOD

ACCESS

FIELD-SUPPLIED DISCONNECT SWITCH LOCATION

125-1/4" (15 Ton) 136-1/4" (20 Ton)

CONTROL BOX ACCESS

FRONT VIEW

UNIT BASE WITH RAILS Shown separately to illustrate Bottom Duct openings, Power and Gas Piping Connection locations

NOTE: For curb mounted units, refer to the curb hanger dimensions of the curb for the proper size of the supply and return air duct connections.

(D) GAS SUPPLY ENTRY

6-3/8"

24-1/4" (15 Ton) 35-1/4" (20 Ton)

35"

11-1/8"

46-5/8"

21"

7-1/8"

9-3/4"

5-7/8"

46-5/8"

RETURN

AIR

33"

2-3/4" 21-1/2"

12-1/2"

ECONOMIZER / MOTORIZED DAMPER, FIXED OUTDOOR INTAKE AIR AND POWER EXHAUST RAIN HOODS (See detail "Y")

92"

11-1/2"

BOTTOM SUPPLY

AND RETURN

AIR OPENINGS

(See Note)

SUPPLY

AIR

8-1/8"

9-1/4"

9-3/4"

COMPRESSOR ACCESS

OPTIONAL COIL GUARD KIT

48-5/8" (15 Ton) 52-5/8" (20 Ton)

CONDENSER COILS

(A) CONTROL WIRING ENTRY

(B) POWER WIRING ENTRY

3-3/4"

(B) POWER WIRING ENTRY

(A) CONTROL WIRING ENTRY

RETURN AIR

SUPPLY AIR

OUTDOOR AI

OUTDOOR AI (Economizer)

All dimensions are in inches. They are subject tochange without notice. Certified dimensionswill be provided upon request.

FIGURE 10 : UNIT DIMENSIONS DHG180 & 240 (FRONT VIEW)

E C O N O M I Z E R

P O W E R

E X H A U S T

S U P P L Y A I R C O M P A R T M E N T

R A I N

H O O D

R e t u r n A i r C o m p a r t m e n t )

( o n

R E A R V I E W

FIGURE 11 : UNIT DIMENSIONS DHE/DHG180 & 240 (RAINHOOD)

M O T O R I Z E D D A M P E R R A I N H O O D ( o n O u t d o o r A i r C o m p a r t m e n t )

3 6 "

6 6 - 1 / 2 "

E C O N O M I Z E R

P O W E R E X H A U S T R A I N H O O D S

A N D

3 4 - 1 / 4 "

5 "

2 "

3 6 - 1 / 4 "

D E T A I L " Y "

U N I T W I T H R A I N H O O D S

1 6 - 1 / 8 "

M O T O R I Z E D D A M P E R

F I X E D O U T D O O R I N T A K E ( l o c a t e d o n R e t u r n A i r C o m p a r t m e n t )

H O O D

A I R

L H V I E W

1 " C O N D E N S T A T E D R A I N ( M u s t b e t r a p p e d )

9 2 "

14 Unitary Products

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035-17233-000-C-0702

G A U G E L I N E A C C E S S

C O M P R E S S O R A C C E S S

C O N D E N S E R S E C T I O N

4 0 - 3 / 8 "

5 - 1 / 2 "

S U P P L Y A I R A C C E S S

S U P P L Y A I R

1 8 - 5 / 8 "

R E T U R N A I R

O U T D O O R A I R

R E A R

V I E W

2 7 - 3 / 4 "

R E T U R N A I R A C C E S S

5 - 1 / 8 "

2 8 - 5 / 8 " ( 1 5 T o n s ) 3 9 - 5 / 8 " ( 2 0 T o n s )

FIGURE 12 : UNIT DIMENSIONS DHE/DHG180 & 240 (REAR VIEW)

E V A P O R A T O R S E C T I O N

4 0 - 1 / 2 "

O U T D O O R A I R C O M P A R T M E N T A C C E S S

D O T P L U G ( F o r p r e s s u r e d r o p r e a d i n g )

F I L T E R A C C E S S

1 " N P T F E M A L E C O N D . D R A I N C O N N E C T I O N

NOTE: A 1” clearance must be provided between any combustiblematerial and the supply air ductworkfor adistanceof 3 feet from the unit.

NOTE:

The products of combustion must not be allowedto

accumulate within a confinedspace and recirculate.

NOTE:

Locate unit so that the vent air outlet hood isat least:

• Three (3)feet above any force airinlet located within 10 horizontal feet (excluding those integral to the unit).

• Four (4) feet below, 4 horizontal feet from, or 1 foot above anydoor or gravity air inlet into the building.

• Four (4)feet from electric andgas meters, regulators and relief equipment

NOTE:

All entry holes should be field sealed to prevent rain

water entryinto building Duct Covers - Units are shipped with the bottom duct open-

ings covered. An accessory flange kit is available for connectingsideducts.

For bottomduct applications:

1. Remove the side panels from the supply andreturn air compartments.

2. Remove and discard the bottom duct covers. (Duct openings are closed withsheet metal covers except when the unit includes a power exhaust option. The covering consists of a heavy black paper composition.)

TABLE 10: UTILITIES ENTRY

HOLE

3. Replace the side supply and return air compartment pan-

For sideduct applications:

1. Replace the side panels on the supply and return air

2. Connect ductwork to theduct flanges on the rear of the

OPENING SIZE

(DIA.)

C D

1” Gas Piping MPT Required.

Opening inthe bottom to the unit can be located by the

1-1/8” KO

3/4” NPS (Fem.) Bottom

3-5/8” KO

3” NPS (Fem.) Bottom

2-3/8” KO

1-11/16” Hole

Control Wiring

Power Wiring

USED FOR

Gas Piping (Front)

Gas Pipping (Bottom)

Front

side inthe insulation.

els.

compartments with the accessory flange kit panels.

unit.

Unitary Products 15

Page 16

TABLE 11: DHG 15 TON SUPPLY AIR BLOWER PERFORMANCE

DHG180 - BOTTOM DUCT CONNECTIONS

BLOWER

SPEED,

(RPM)

MOTOR

PULLEY

(TURNS

OPEN)

4500 5250 6000 6750 7200

ESP

BHP KW

208 VOLT AND STANDARD DRIVE

850 870 5.5 915 4.5 965 3.5

980 3.0 1010 2.0 1040 1.0

6.0

0.9 2.4 2.1 0.6 2.9 2.6 0.3 3.4 3.0 - - - - - -

1.0 2.5 2.2 0.7 3.0 2.7 0.4 3.5 3.1 - - - - - -

1.1 2.6 2.4 0.8 3.1 2.8 0.5 3.6 3.2 0.2 4.1 3.7 - - -

1.2 2.7 2.5 0.9 3.2 2.9 0.6 3.7 3.3 0.4 4.4 3.9 0.2 5.0 4.5

1.3 2.9 2.6 1.0 3.4 3.0 0.7 3.8 3.4 0.5 4.5 4.0 0.3 5.1 4.6

1.4 3.0 2.7 1.1 3.6 3.2 0.8 4.0 3.6 0.6 4.7 4.2 0.4 5.4 4.8

1.6 3.2 2.9 1.3 3.8 3.4 1.0 4.4 3.9 0.8 5.0 4.5 0.6 5.6 5.0

1, 2

ESP

BHP KW

ESP

CFM

BHP KW

FIGURE 13 : 208 VOLT AND HIGH SPEED DRIVE ACCESSORY

965 6.0

980 5.5 1025 4.5 1065 3.5 1125 2.0 1170 1.0

230/460 VOLT AND STANDARD DRIVE

870

915 5.0

965 4.0

980 3.5 1015 2.5 1050 1.5 1065 1.0

6.0

230/460 VOLT AND HIGH SPEED DRIVE ACCESSORY

980 6.0 1045 4.5 1065 4.0 1125 2.5 1170 1.5 1190 1.0

Blower performance includes a gas -fired heat exchanger, fixed outdoor air, 2” T/A filtersand a dry evaporator coil.

Refer to the Static Resistance table.

DO NOT close the pulley below one turn open.

ESP = External Static Pressure available for the supplyand return air duct system. All inter nal unit resistances have been deducted from the total static pressure of the blower.

The factory setting.

1.2 2.7 2.5 0.9 3.2 2.9 0.6 3.7 3.3 0.4 4.4 3.9 0.2 5.0 4.5

1.3 2.9 2.6 1.0 3.4 3.0 0.7 3.8 3.4 0.5 4.5 4.0 0.3 5.1 4.6

1.4 3.1 2.8 1.2 3.6 3.2 0.9 4.1 3.7 0.7 4.8 4.3 0.4 5.5 4.9

1.6 3.4 3.0 1.4 3.9 3.5 1.1 4.5 4.0 0.9 5.1 4.6 - - -

1.9 3.6 3.2 1.7 4.4 3.9 1.4 5.0 4.5 1.2 5.8 5.2 - - -

2.1 3.9 3.5 1.9 4.7 4.2 1.6 5.5 4.9 - - - - - -

1.0 2.5 2.2 0.7 3.0 2.7 0.4 3.5 3.1 - - - - - -

1.1 2.6 2.4 0.8 3.1 2.8 0.5 3.6 3.2 0.2 4.1 3.7 - - -

1.2 2.7 2.5 0.9 3.2 2.9 0.6 3.7 3.3 0.4 4.4 3.9 0.2 5.0 4.5

1.3 2.9 2.6 1.0 3.4 3.0 0.7 3.8 3.4 0.5 4.5 4.0 0.3 5.1 4.6

1.4 3.0 2.7 1.1 3.6 3.2 0.8 4.0 3.6 0.6 4.7 4.2 0.4 5.4 4.8

1.5 3.1 2.8 1.2 3.7 3.3 0.9 4.2 3.8 0.7 4.9 4.4 0.5 5.7 5.1

1.6 3.4 3.0 1.4 3.9 3.5 1.1 4.5 4.0 0.9 5.1 4.6 - - -

1.3 2.9 2.6 1.0 3.4 3.0 0.7 3.8 3.4 0.5 4.5 4.0 0.3 5.1 4.6

1.6 3.2 2.9 1.3 3.8 3.4 1.0 4.4 3.9 0.8 5.0 4.5 0.6 5.6 5.0

1.7 3.4 3.0 1.4 3.9 3.5 1.1 4.5 4.0 0.9 5.1 4.6 - - -

1.9 3.6 3.2 1.7 4.4 3.9 1.4 5.0 4.5 1.2 5.8 5.2 - - -

2.1 3.9 3.5 1.8 4.7 4.2 1.6 5.5 4.9 - - - - - -

2.2 4.0 3.6 1.9 4.8 4.3 1.7 5.6 5.0 - - - - - -

ESP

BHP KW

035-17233-000-C-0702

BHP KW

ESP

16 Unitary Products

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035-17233-000-C-0702

TABLE 12: DHG 20 TON SUPPLY AIR BLOWER PERFORMANCE

DHG240 - BOTTOM DUCT CONNECTIONS

BLOWER

SPEED,

(RPM)

MOTOR

PULLEY

(TURNS OPEN)

6000 7000 8000 9000 9400

ESP

BHP KW

208 VOLT AND STANDARD DRIVE

870 900 5.0 930 4.0 950 3.0 980 2.0 995 1.5

1015 1.0

6.0

1.3 3.6 3.0 0.7 4.3 3.7 0.2 5.1 4.3 - - - - - -

1.4 3.8 3.2 0.9 4.7 4.0 0.4 5.6 4.7 - - - - - -

1.6 4.1 3.4 1.1 5.0 4.2 0.6 5.9 5.0 0.1 6.7 5.7 - - -

1.7 4.2 3.6 1.3 5.1 4.3 0.8 6.0 5.1 0.2 6.9 5.8 - - -

1.9 4.5 3.8 1.5 5.4 4.5 1.0 6.3 5.3 0.4 7.2 6.1 0.1 8.5 7.1

2.1 4.6 3.9 1.6 5.5 4.7 1.1 6.4 5.4 0.5 7.5 6.3 0.2 8.6 7.3

2.2 4.8 4.0 1.7 5.7 4.8 1.2 6.6 5.6 0.7 7.8 6.6 - - -

208 VOLT AND HIGH SPEED DRIVE ACCESSORY

950 6.0 980 5.0

995 4.5 1025 3.5 1050 2.5 1065 2.0 1100 1.0

1.7 4.2 3.6 1.3 5.1 4.3 0.8 6.0 5.1 0.2 6.9 5.8 - - -

1.9 4.5 3.8 1.5 5.4 4.5 1.0 6.3 5.3 0.4 7.2 6.1 0.1 8.5 7.1

2.1 4.6 3.9 1.6 5.5 4.7 1.1 6.4 5.4 0.5 7.5 6.3 0.2 8.6 7.3

2.3 4.9 4.1 1.8 5.8 4.9 1.3 6.7 5.7 0.7 8.0 6.7 - - -

2.5 5.1 4.3 2.0 6.1 5.1 1.4 7.1 6.0 0.9 8.4 7.0 - - -

2.6 5.3 4.4 2.1 6.3 5.3 1.5 7.3 6.2 1.0 8.6 7.2 - - -

2.9 5.6 4.7 2.3 6.8 5.7 1.8 7.9 6.6 - - - - - -

230/460 VOLT AND STANDARD DRIVE

870

900 5.0

930 4.0

950 3.5

965 2.5

995 2.0 1015 1.5 1025 1.0

6.0

1.3 3.6 3.0 0.7 4.3 3.7 0.2 5.1 4.3 - - - - - -

1.4 3.8 3.2 0.9 4.7 4.0 0.4 5.6 4.7 - - - - - -

1.6 4.1 3.4 1.1 5.0 4.2 0.6 5.9 5.0 0.1 6.7 5.7 - - -

1.7 4.2 3.6 1.3 5.1 4.3 0.8 6.0 5.1 0.2 6.9 5.8 - - -

1.9 4.5 3.8 1.5 5.4 4.5 1.0 6.3 5.3 0.4 7.2 6.1 0.1 8.5 7.1

2.1 4.6 3.9 1.6 5.5 4.7 1.1 6.4 5.4 0.5 7.5 6.3 0.2 8.6 7.3

2.2 4.8 4.0 1.7 5.7 4.8 1.2 6.6 5.6 0.6 7.8 6.6 - - -

2.3 4.9 4.1 1.8 5.8 4.9 1.3 6.7 5.7 0.7 8.0 6.7 - - -

230/460 VOLT AND HIGH SPEED DRIVE ACCESSORY

950 6.0

980 5.0

995 4.5 1015 4.0 1025 3.5 1050 3.0 1065 2.5 1100 1.5 1120 1.0

Blower performance includes a gas -fired heat exchanger, fixed outdoor air, 2” T/A filters and a dry evaporator coil.

Refer to the Static Resistance table.

DO NOT close the pulley below one turn open.

ESP = External Static Pressure available for the supplyand return air duct system. All inter nal unit resistances have been deducted from the total static pressure of the blower.

The Factory Setting

1.7 4.2 3.6 1.3 5.1 4.3 0.8 6.0 5.1 0.2 6.9 5.8 - - -

1.9 4.5 3.8 1.5 5.4 4.5 1.0 6.3 5.3 0.4 7.2 6.1 0.1 8.5 7.1

2.1 4.6 3.9 1.6 5.5 4.7 1.1 6.4 5.4 0.5 7.5 6.3 0.2 8.6 7.3

2.2 4.8 4.0 1.7 5.7 4.8 1.2 6.6 5.6 0.6 7.8 6.6 - - -

2.3 4.9 4.1 1.8 5.8 4.9 1.3 6.7 5.7 0.7 8.0 6.7 - - -

2.5 5.1 4.3 2.0 6.1 5.1 1.4 7.1 6.0 0.9 8.4 7.0 - - -

2.6 5.3 4.4 2.1 6.3 5.3 1.5 7.3 6.2 1.0 8.6 7.2 - - -

2.9 5.6 4.7 2.3 6.8 5.7 1.8 7.9 6.6 - - - - - -

3.1 5.8 4.9 2.5 7.0 5.9 1.9 8.3 6.9 - - - - - -

1, 2

ESP

BHP KW

ESP

CFM

BHP KW

ESP

BHP KW

ESP

BHP KW

Unitary Products 17

Page 18

035-17233-000-C-0702

TABLE 13: STATIC RESISTANCES

DESCRIPTION

WET COIL ECONOMIZER OPTION

HORIZONTALDUCT CONN.

Deduct these resistance values from the available unit ESP values listed in the respective blower per-

15 TON 20 TON

4500 5765 7200 6000 7000 9400

0.1 0.1 0.1 0.1 0.1 0.1

0.2 0.3 0.5 0.2 0.3 0.5

formance tableexcept for Horizontal Duct Connections.

Add thesevalues due to less airflow resistance.

TABLE 14: POWER EXHAUST PERFORMANCE

MOTOR

SPEED

HIGH

MEDIUM

LOW

Power exhaust motor is a 3/4 HP,PSC type with sleeve bearings, a 48 frame and inherent protection.

The factory setting.

0.2 0.3 0.4 0.5 0.6

CFM kW CFM kW CFM kW CFM kW CFM kW

5250 0.83 4500 0.85 4200 0.88 3750 0.93 3000 0.99 4900 0.77 3900 0.79 3500 0.82 2900 0.85 - 4400 0.72 3700 0.74 3000 0.78 ----

STATIC RESISTANCE OF RETURN DUCTWORK, IWG

RESISTANCE,IWG

CFM

TABLE 15: BLOWER MOTOR AND DRIVE DATA

MODEL

15 Ton

20 Ton

DRIVE

SIZE

High Spd.

Acs.

High Spd.

Acs.

All motors havea nominal speed of 1800 RPM, a1.15 service factor and as olid base. They can operate tothe limit oftheir service

BLWR

RANGE

(RPM)

Std. 850/1065

965/1190 BK80 7.75 7.4 1 BX68

Std. 870/1025

950/1120 BK110 10.75 10.4 1-3/16 BX80

MOTOR

HP FRAME

5 184T 89.5 1VP56 5.35

7.5 213T 91 1VP68 6.75

EFF.

(%)

factor because they are located in the moving air, upstream of any heating device.

DO NOT close this pulley below 1 turn.

ADJ. MOTOR PULLEY FIXED BLOWER PULLEY

DESIGN-

NATION

O/D (in.)

PITCH

DIA (in.)

4.3-

5.3

5.5-

6.5

BELT

(NOTCHED)

PITCH

BORE

DESIGN-

(in.)

NATION

BK90 8.75 8.4 1 BX70

1-1/8

BK120 11.75 11.4 1-3/16 BX83

1-3/8

O/D (in.)

DIA

(in.)

DESIG-

NATION

PITCH

LNGTH.

(in.)

71.8 1

69.8 1

84.8 1

81.8 1

QTY.

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OPERATION

COOLING SYSTEM

The cooling section isa complete factory package utilizing an air-cooled condenser. The system is factory-charged with Refrigerant-22.

The compressors are hermetically sealed, internally sprung and base-mounted withrubber-insulated hold-down bolts.

Compressorshave inherent (internal) protection. Ifthere is an abnormal temperature rise in a compressor, the protector will open toshut down the compressor.

PRELIMINARY OPERATION COOLING

After installation has been completed, energize the crankcase heaters for at least four hours before operating the unit. After the initial installation, the compressors should be given three false starts (energized just long enough to make a few revolutions) with 5-7 minutes delay between each start, before being put into full timeservice.

NOTE:

must be energized at least 8 hours before system is put into operation.

COOLING SEQUENCE OF OPERATION

NO OUTDOOR AIR OPTIONS

When the room thermostat calls for first-stage cooling, the low voltage control circuitfrom R toG and Y1 is completed to energize compressor #1, condenser fan motor #1,condenser fan motor #2 (if the ambient temperature is above 60F), and the supply air blower motor (if the fan switch on the room thermostat is set in the AUTO position).

When the thermostat calls for second-stage cooling, the low voltage control circuit from R to Y2 is completed to energize compressor #2.

After the thermostat is satisfied and opens, all components will stop simultaneously. The blower motor will continue to operate if the fan switch on the room thermostat is set in the ON position.

ECONOMIZER WITH SINGLE ENTHALPY SENSOR

When the room thermostat calls for first-stage cooling, the low voltage control circuit from R to G and Y1 is completed. The R to G circuit energizes the blower motor (if the fan switch on the room thermostat is set in the AUTO position) and drives the economizer dampers from fully closed to their minimum position. If the enthalpy of the outdoor air is below the setpoint of the enthalpy controller (previously determined), Y1 energizes the economizer. The dampers will

Prior to each cooling season, the crankcase heaters

modulate to maintain a c onstant supply air temperature as monitored by the discharge air sensor. If the outdoor air enthalpy is above the setpoint, Y1 energizes compressor #1, condenser fan motor #1, and condenser fan motor #2 (if the ambient temperature is above 60°F).

When the thermostat calls for second-stage cooling, the low voltage control circuit from R to Y2 is completed. If the enthalpy of the outdoor air is below the setpoint of the enthalpy controller (i.e. first stage has energized the economizer), Y2 will energize compressor #1. If the outdoor air is above thesetpoint, Y2 will energize compressor #2.

After the thermostat is satisfied and opens, all components will stop simultaneously. The blower motor will continue to operate if the fan switch on the room thermostat is set in the ON position.

ECONOMIZER WITH DUAL ENTHALPY SENSORS

The operation with the dual enthalpy sensors is identical to the single sensor except that a second enthalpy sensor is mounted in the return air. This return air sensor allows the economizer to choose between outdoor air and return air, whichever has the lowest enthalpy value, to provide maximum operating efficiency.

ECONOMIZER (SINGLE OR DUAL) WITH POWER EXHAUST

This system operates as specified above with one addition. The power exhaust motor is energized whenever the economizer ischosen by the enthalpy sensor for first stage cooling, Y1. As always, the R to G connection provides minimum position but does not provide power exhaust operation.

MOTORIZED OUTDOOR AIR DAMPERS

This system operation is the same as the units with no outdoor air options with oneexception. When theR toG circuitis complete,themotorizeddamperdrivesopentoapositionset by the thumbwheel on the damper motor. When the R to G circuit isopened, the damper spring returns fullyclosed.

CONTINUOUS BLOWER

Continuousblower operationis possible by closing the R toG circuit on the thermostat.

SAFETY CONTROLS

1. A Suction LineFreezestat toprotect against low evaporator temperatures dueto a low air flow or a low return air temperature. (Opens at26°F + 5°Fand resets at38°F + 5°F)

2. A High Pressure Cutout Switch to protect againstexcessive discharge pressures due to a blockedcondenser coil ora condenser motor failure. (Opens at 380 psig + 10 and resets at 300 psig +10)

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3. A Low Pressure Switch/Loss Of Charge to protect against loss of refrigerant charge. (Opens at 7 psig + 3 andresetsat22psig+5)

If either one of the above safety controls opens, that individual refrigerant system will be locked out.The otherrefrigerant system will continue in operation unless it too is effected by the same fault. The lock out of either system can be reset by opening the 24V circuit eitherat the room thermostator atthe unit disconnect.

HEATING SYSTEM

The following sequence describes the operation of the gas heat section.

CONTINUOUS BLOWER

With the room thermostat switch set to ON, the supply air blower will operatecontinuously. Thenormally closedcontact K5-1 provides 24volt power to the M3 contactor.The M3-1, 2 & 3 power contactsclose and the blowermotor operates.

INTERMITTENT BLOWER

With the room thermostat system switch set to the AUTO or HEAT position and the fan switch set to AUTO, the supply air blower will operate after the room thermostat calls for heat and the time delay relay closes.

The TH1 closes, the heat relay RW1 is energized. The RW11 power contact closes energizing the line voltage draft motor. The RW1-2 contactis also closed. As the speed of the draft motor reachesapproximately 2500 RPM, the centrifugal switch contact located on the end of the draft motor shaft closes topower the first stage ignitionmodule IC1.

REDUNDANT VALVE

GAS MAIN

MAIN VALVE

Gas flows into each of the main burners and is ignited from the carryovertube flame.

If IC1 fails to detect a pilot flame, it will continue to try for a maximum of 85 seconds to ignite the pilot tube. If the pilot flame isnot detected, thenIC1 will lock out first stage furnace operation until 24V power is removed from the module either at the unit or by resetting the room thermostat.

At the same time power was supplied to the RW1, a parallel circuit activates ETD which closes the ETD contact after approximately 35 seconds and energizes K5 which closes K5-2 and starts the blower by energizingM3.

When TH2 closes, heat relay RW2 is energized. The RW2-1 contact is closed energizing thesecond stage ignition module IC2. IC2will immediatelystart the second stage ignitor sparking and will open the redundant valve located inside the second stage main gas valve GV2 to allow a flow of gas to the second stage carryover tube. See Figure 11. Only after the pilot flame has been ignited and the presence of pilot flame detected at IC2 by a signal sent back through the flame sensor is sparking terminatedand the main gas valve opened.

Gas flows into each of the second stage main burners and is ignited fromthe carryover tube flame.

If IC2 fails to detect a pilot flame, it will continue to try for a maximum of 85 seconds to ignite the pilot tube. If the pilot flame isnot detected, thenIC2 will lock out first stage furnace operation until 24V power is removed from the module either at the unit or by resetting the room thermostat. Note that the second stage furnace can operate even if first stage has locked out.

When the heating cycle is complete, TH2 opens de-energizing the RW2 then TH1 opens de-energizing RW1 and ETD, thus closing all gas valves. The blower motor will continue to run (approximately 45 seconds after the furnace is shut down) until ETD opens, de-energizing the K5 relay and M3 contactor.

SAFETY CONTROLS

GAS VALVE

TO PILOT BURNER

FIGURE 14 : GAS VALVE PIPING

Ignition module IC1 will immediately start the first stage ignitor sparking and will open the redundant valve located inside the first stage main gas valve GV1 to allow a flow of gas to only the first stage carryover tube. See Figure 14. Only after the pilot flame has been ignited and the presence of pilot flame detected at the IC1 by a signal sent back through the flame sensor is sparking terminated and the first stage main gas valveopened.

TO MAIN BURNER

The controlcircuit includesthe following safety controls:

1. Limit Control (LS). Thiscontrol is located inside the heat exchanger compartment and is set to open at the temperature indicated inTable 16.It resets automatically. The limitswitch operates when a high temperature condition, caused byinadequate supply airflow occurs, thus shutting down the ignition control and closing the main gas valves and energizing the blower.

2. CentrifugalSwitch (CS).If thedraft motor should fail, the centrifugal switch attached to the shaft of the motorprevents the ignition controls and gas valves from being energized.

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TABLE 16: LIMIT CONTROL SETTING

I G N . C O N T R O L # 2

I G N . C O N T R O L # 1

R O L L O U T S W .

S E N S O R # 1

I G N I T O R # 2

G V 2 G A S

V A L V E

G V 1 G A S

V A L V E

I G N I T O R # 1

S E N S O R # 2

B U R N E R C O M P A R T M E N T

FIGURE 15 : GAS VALVE AND CONTROLS

3. Redundant Gas Valve - There are twoseparate gas valves in the furnace. Each valvecontains a main and a redundant valve. The redundantvalves are located upstream of the main gas valves. Should either or both of the main gas valves fail in the open position theredundant valves serve as back-ups and shuts off the flow of gas.

4. Flame Sensor Rod / 100% Ignition Control Lock-Out The flame rods and controls are located per Figure 15. If an ignitioncontrol fails to detect a signal from the flame sensor indicating the pilotflame is properly ignited,then the maingas valve will not open. It will continue to try and ignite the pilot for amaximum of 85 seconds, then if the pilotflame is not detected, the ignition control will lock outfurnace operationuntil 24V power is removed from themodule either at the unit or by resetting the room thermostat.

Units

(Tons)

15 & 20 300 240 195 15 & 20 400 320 195

Capacity, M BH

Input Output

Limit

Control

Opens, °F

HEAT ANTICIPATOR SETPOINTS

It is important that the anticipator setpoint be correct. Too high ofa setting will result in longer heat cycles and a greater temperature swing in the conditioned space. Reducing the value below the correct setpoint will give shorter ON cycles and may result in the lowering of the temperature within the conditioned space.

TABLE 17: HEAT ANTICIPATOR SETPOINT

Gas Valve 1st Stage 2nd Stage

Honeywell VR8440

White-Rodgers 36C68

0.30 amp 0.11 amp

START UP

PRE-START CHECK LIST

Complete thefollowing checksbefore starting the unit.

1. Check the type of gas being supplied. Be sure that it is the same as listed onthe unit nameplate.

2. Make sure that the vent and combustion airhoods have been properly installed.

OPERATING INSTRUCTIONS

5. Rollout Switch - Thisswitch is located above themain burners in the control compartment which in the event of a sustained main burner rollout shuts off and locks out both ignition controls closing both gas valves. The ignition controls lock out furnace operation until24V power is removed from the controls either at the unit or by

This furnace is equipped with an intermittent pilot and automatic re-ignitionsystem. DO NOT attempt to manually light the pilot.

resettingthe roomthermostat. Note theauto reset rollout switch must reset before allowing furnace operation.

6. Auxiliary limit switch (AUX) - This control is located inside theheat exchangercompartment and is set to open at190F. It is a manual reset switch. If AUX limit trips, then the primary limit hasnot functioned correctly.

TO LIGHT PILOT AND MAIN BURNERS:

1. Turn off electric power to unit.

2. Turn room thermostat to lowest setting.

3. Turn gas valve knob to on position.

Replace the primary limit switch.

4. Turn on electric power to unit.

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5. Set room thermostat to desired temperature.(If thermostat set temperature is above room temperature, pilot burner ignition willoccur and, after an intervalto prove pilot flame, main burners will ignite).

TO SHUT DOWN:

1. Turn off electric power to unit.

2. Depressknob of gasvalve while turning to offposition.

POST-START CHECK LIST (GAS)

After the entire control circuit has been energized and the heating section is operating,make the following checks:

1. Check for gas leaksin the unit piping as well asthe supply piping.

2. Checkfor correct manifold gas pressures.See Checking Gas Input.

3. Check the supply gas pressure. Itmust be within the limits s hown on rating nameplate. Supply pressure should be checked with all gas appliances inthe building at full fire. At no time should the standby gas line pressure exceed 13", nor the operating pressure dropbelow 5.0" for natural gas units. If gaspressure is outside these limits, contact the local gas utilityfor corrective action.

MANIFOLD GAS PRESSURE ADJUSTMENT

Adjust as follows:

1. Remove the cap on the regulator. It's located next tothe push-on electrical terminals.

2. To decrease the gas pressure, turn the adjusting screw counterclockwise.

3. To increase the gas pressure, turn the adjustingscrew clockwise.

The correct manifold pressure for these furnaces is

NOTE:

3.5 IWG0.3.

PILOT CHECKOUT

The pilot flame should envelope the end of the flame sensor. Refer to Figure 16. To adjust pilot flame, (1) remove pilot adjustment cover screw, (2) increase or decrease the clearance for air to the desired level, (3) be sure to replace cover screw after adjustment to prevent possible gas leakage.

Put the system into operation and observe through complete cycle to be sure all controls function properly.

B U R N E R A S S E M B L Y B R A C K E T

F L A M E S E N S O R B U L B

Small adjustments to the high-fire gas flow may be made by turning the pressure regulator adjusting screw on the automatic gasvalve. Refer to Figure 16.

On-Off Control

Pilot Adj. (Under Screw)

High F ire Adj. (Under Screw)

FIGURE 16 : TYPICAL GAS VALVE

1 / 8 " G A P B E T W E E N C A R R Y - O V E R T U B E A N D F L A M E S E N S O R B U L B

C A R R Y - O V E R T U B E

FIGURE 17 : PROPER FLAME ADJUSTMENT

BURNER INSTRUCTIONS

To check or change burners, pilot or orifices, CLOSE MAIN MANUAL SHUT-OFF VAL VE AND SHUT OFF ALL ELECTRIC POWER TO THE UNIT.

1. Removethe screwsholding either endof themanifold to the burner supports.

2. Open the union fitting in the gassupply line just upstreamof the unit gas valve and downstream fromthe main manual shut-off valve.

3. Remove the gas piping closurepanel.

4. Disconnect wiring to the gas valves and spark ignitors. Remove the manifold-burner gasvalve assemblyby lifting up and pulling back.

Burners are now accessible for service.

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Reverse the above procedure to replace the assemblies. Make sure that burners are level and seat at the rear of the heat exchanger.

BURNER AIR SHUTTER ADJUSTMENT

Adjust burner shutters so no yellow flame is observed in the heat exchanger tubes. Refer to Figure 17.

CHECKING SUPPLY AIR CFM

The RPMof the supply airblower will depend on therequired CFM, the unit accessories or options and the static resistances of both the supply and the return air duct systems. With this information, the RPM for the supply air blower and the motor pulley adjustment (turns open) can be determined from theblower performance data in Tables 11 and 12.

High speed drive accessories (containing a smaller blower pulley and a shorterbelt) are available for applications requiring the supply air blower to produce higher CFM's and/or higher static pressures. Use Model 1LD0416 for 15 ton units and Model 1LD0417 for 20 ton units. Refer to Table 15 for

blower motor and drive data.

Procedure for adjusting belt tension:

Loosen nuts (A) (top and bottom).

2. Adjust the tension by turning bolt (B).

3. Never loosen nuts (C) from each other.

4. Use a belt tension checker to apply a perpendicular force to one belt at the midpoint of the span as shown. The deflection force should be applied until a specific deflection distance of 4mm (5/32")is obtained. To determine the deflection distance from normal position, use a straight edge from sheave to sheave as a reference line. The recommended deflection force is as follows:

SPAN LENGTH

DEFL FORCE

(B)

* Never Loosen

(A)

Tension new belts at the max. deflection force recommended for the belt section. Check the belt tension at least two times during the first 24 hours of operation. Any re tensioning should fall between the min. and max. deflection force values.

5. After adjusting, re tighten nuts (A).

(C)*

FIGURE 18 : TYPICAL FLAME APPEARANCE

Note the following:

1. The supply air CFM must be within the limitations shown in Table 2.

2. Pulleyscanbeadjustedinhalfturnincrements.

3. The tension on the belt should be adjusted as shown in Figure 19.

Start the supply air blower motor. Adjust the resistances in both the supply and the return air duct systems to balance the air distribution throughout the conditioned space. The job specifications may require that this balancing be done by someone other than the equipment installer.

To check the supply air CFM after the initial balancing has been completed:

1. Remove the two 5/16"dot plugs from the blower motor and thefilter access panels shown in Figure 10.

FIGURE 19 : BELT ADJUSTMENT

2. Insert at least 8" of 1/4 inch tubing into eachof these holes forsufficient penetration intothe air flowon both sides ofthe indoor coil.

NOTE:

The tubes must be insertedand heldin aposition perpendicular to the air flow so that velocity pressure will not affect the static pressure readings.

3. Using an inclined manometer,determine the pressure

drop across a dry evaporator coil. Since the moisture on an evaporator coil may vary greatly, measuring the pressure dropacross a wetcoil under field conditions would be inaccurate. To assure a dry coil, the compressors should be deactivated while the test is beingrun.

4. Knowing the pressure dropacross a drycoil, the actual

CFM through the unit and clean 2" filters, can be determined fromthe curve in Figure 20.

After readings have been obtained, remove the tubes and reinstall the two 5/16" dot plugs thatwere removed in Step 1.

Failure to properly adjust thetotal systemair quantity canresult in extensive blower damage.

NOTE:

De-energize the compressors before taking any test measurements to assure a dry indoor coil.

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035-17233-000-C-0702

2. Withthe furnace turned on,measure the timeneeded for one revolution ofthe hand onthe smallest dial on the meter. A typical gas meter usually has a 1/2 or a 1 cubic foot testdial.

3. Usingthe number of secondsfor each revolutionand the size ofthe test dialincrement, find the cubic feetof gas consumed per hour from Table18.

If the actual input is not within 5% of the furnace rating (with allowance being made for the permissible range of the regulator setting), replace the orifice spuds with spuds of the proper size.

To find the Btu input, multiply the number of cubic feet

NOTE:

of gas consumed per hour by the Btu content of the gas in your particular locality (contact your gas company for this information - it varies widely from city to city.)

FIGURE 20 : PRESSURE DROP ACROSS A DRY

INDOOR COIL VS. SUPPLY AIR CFM

ADJUSTMENT OF TEMPERATURE RISE

The temperature rise (or temperature difference between the return air and the heated air from the furnace) must lie within the range shown on the ETL ratingplate andthe data in Table

2. After the temperature rise has been determined, the cfm can

be calculated as follows:

BtuhbInput 0.8×

CFM

After about 20 minutes of operation, determine the furnace temperature rise. Take readings of both the return airand the heated air in the ducts(about sixfeet fromthe furnace) where they will not be affected by radiant heat. Increase the blower cfm to decrease the temperature rise; decrease the blower cfm to increase the rise. Refer to Table 11 for blower motor and drive data.

BELT DRIVE BLOWER

All units have belt drive single-speed blower motors. The variable pitch pulley on the blower motor can be adjusted to obtain the desired supply air CFM. Tighten belts enough to prevent slipping. but do not over tighten. Belt deflection should be between 1/4" and 1/2" per foot. Refer to Table 15 for blower motor and drive data.

--------------------------------------------------------

1.08 ° FbTempbRise×

TABLE 18: GAS RATE - CUBIC FEET PER HOUR

SECONDS FOR 1 REV.

4 450 900 6 300 600

8 228 450 10 180 360 12 150 300 14 129 257 16 113 225 18 100 200 20 90 180 22 82 164 24 75 150 26 69 138 28 64 129

Example: By actual measurement, it takes 13 seconds for the hand on the 1-cubic foot dial to make a rev olution with just a 300,000 Btuh furnace running. Read across to the column in the table above, headed “1 Cubic Foot”,where you will see that 278 cubic feet of gas per hourare consumed bythe furnace atthat rate. Multiply 278 X 1050 (the Btu rating of the gasobtained from the local gas company). The result is 292,425 Btuh, which is close to the 3000,000 Btuh rating of the furnace.

SIZE OF TESTDIAL

1/2 Cu. Ft. 1 Cu. Ft.

SECURE OWNER’S APPROVAL

CHECKING GAS INPUT

NATURAL GAS

1. Turn off all other gas appliances connected to the gas meter.

When system is functioning properly, secure the owner’s approval. Show him the location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust temperature settings within the limitations of the system.

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MAINTENANCE

NORMAL MAINTENANCE

Prior to any of the following maintenance procedures, shut off all electric power to the unit to prevent personal injury.

Periodic maintenance normally consists of changing or cleaning filters and (under some conditions) cleaning the main burners

FILTERS

Inspect once a month. Replace disposable or clean permanent type as necessary. DO NOT replace permanent type with disposable. The dimensional size of the replacement filter mustbe the same as the replaced filter.

MOTORS

Outdoor fan motors are permanently lubricated and require no maintenance.

If desired, every three years remove both pipe plugs at each end shell and clean out any hardened grease or foreign matter.Replace one plug on each end with a cleangrease fitting. Using a low pressure grease gun, pump grease (Chevron SRI-2 or equivalent) into the bearing cavity until new grease shows at the open port. Do not over lubricate. Run the motor for ten minutes until excess grease is purged from the cavity. Replace the plugs.

On 20 ton only, units are supplied with blower shaft bearings that do not require maintenance but may be relubricated if desired. Every three years, using a low pressure grease gun, pump grease into the bearing grease fitting until grease just begins to show at the seals. Do not over lubricate. Use any lithium base grease recommended for ball bearing service.

OUTDOOR COIL

Dirt should not be allowed to accumulate on the outdoor coil surface or other parts in the air circuit. Cleaning should be as often as necessary to keep coil clean. Use a brush, vacuum cleaner attachment, or other suitable means. If water is used to clean coil, be sure electric power to the unit is shut off prior to cleaning.

Exercise care when cleaning the coil so that the coil

NOTE:

fins arenot damaged.

Ventor motor is factory lubricated for an estimated 10 year life.

Indoor Blower Motorand Drive- Theindoor blower motor features ball bearings that do not require periodic lubrication. Periodic lubrication of the motor and bearings can extend the

life of components butis optional.

Damage can occur if the bearings are overlubricated. Use grease sparingly.

Perform all maintenance operations on the blower motor with electric power disconnected from the unit. Do not attempt to lubricate bearings with the unit inoperation.

On an annual basis, check the motor for accumulations of dust, etc. that may block the cooling slots in the motor shell. Check for loose, damaged or misaligned drive components. Check that all mounting bolts are tight. Replace defective parts as required.

Do not permit the hot condenser air discharge to be

NOTE:

obstructed by overhanging structures of shrubs.

BURNER & PILOT

Periodically (at least annually at the beginning of each heating season) make a visual check of the pilot and main burner flame. If necessary, adjust mainburner primaryair shutters to give adistinct, sharp blueflame as explained underBURNER AIR SHUTTER ADJUSTMENT. If it is not possible to adjust for the proper flame, the burners may need cleaning.

TO CLEAN BURNERS

Remove them from the furnace as explained in Burner Instructions. Clean burners with hot water applied along top of the burner.

COMBUSTION AIR DISCHARGE

Visually inspect discharge outlet periodically to make sure that the buildup of soot and dirt isnot excessive. Ifnecessary, clean tomaintain adequate combustion air discharge.

CLEANING FLUE PASSAGES AND HEATING ELEMENTS

With proper combustion adjustment the heating element of a gas fired furnace will seldom need cleaning. If the element should become sooted, itcan be cleaned as follows:

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1. Remove the burner assembly as outlined in BURNER INSTRUCTIONS.

2. Remove the roof over the gas heatsection.

3. Atthe topplate from thetop draftblower housingand the top draftblower wheel.

4. Remove the screws holding thetop of the flue collector box. Carefully removethe top of the flue collector box without ripping the adjacentinsulation. Then removethe center divider plateseparating the upper and lowerflue boxes.

5. On the insideof the fluecollector box, remove the flue baffles from the tube interiors. Note the last bend of the baffle fits tightly against the tube forcing the endof the baffle to lock into the tube collar. This collar isformed when the tube is expanded into the end sheet. To remove, move the end of the baffle toward the center of the tubereleasing theend of the baffle from the tube collar,then pull straight out of the tube. Referto Figure 20.

6. Using a wire brush on a flexible wand, brush out the inside of each heat exchanger from the burner inlet and flue outlet ends.

7. Brush out the inside of theflue collectorbox andthe flue baffles.

035-17233-000-C-0702

FIGURE 21 : TYPICAL FLUE BAFFLE INSTALLA-

TION

TROUBLESHOOTING

Label all wires prior to disconnection when servicing controls. Wiring errors cancause improperand dangerous operation. Verify proper operation after servicing.

8. Run the wire brush down the vent hoods from the flue collector end.

9. Ifsoot build-up is particularly bad, removethe vent motor and cleanthe wheel and housings. Run the wire brush down theflue extensionsat the outlet of the vent housings.

10. Afterbrushing is complete, blow all brushed areas with air or nitrogen. Vacuum as needed.

11. Replace parts in the orderthey were removed in Steps 1 through 4.

12. When replacing the center and topof the flue collector box, be careful not to tear the adjoining insulation.

13. Ensurethat all seamson thevent side ofthe combustion system are air tight. Apply a high temperature (+500°F) sealing compound where needed.

Troubleshooting of components necessarily requires opening the electrical control box with the power connected to the unit. Use extreme care when working with live circuits! Check the unit nameplate for the correct line voltage and set the volt meter to the correct range before making any connections with line terminals.

Prior to any of the following maintenance procedures, shut off all electric power to the unit to prevent personal injury.

NOTE: To find the Btu input, multiply thenumber ofcubic feet of gas consumed per hour by the Btu content of the gas in your particular locality (contact your gas company for this information - it varies widely from city to city.)

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1. The indoor blower motor is a non-inherently protected three-phasemotor.Protectionis provided by anoverload relay forovercurrent and fuses for short circuit. If the motor fails to run, check the line voltagecircuit and control voltage circuitper the following procedure:

a. If the Indoor Blower Motor does not operate, check

visually that contactor M3 is pulled in. If so, check for line voltage between all three phases at the line terminals of the Blower Overload Relay (BOR). If line voltage is found, check the leads to the blower motor for open circuit. If line voltage is found at the motor leads (inside the conduit box on the motor shell), disconnect the motor and check for open windings per the motor wiring diagram. Ifopen windings are found, replace the motor. If line voltage is not found at the BOR, trace the leads back to the field supply terminal block, checking for an open circuit or blown fuses.

b. If the contactor M3 is not pulled in, check for control

voltage (24V) at the M3 coil. If voltage is found, replace the contactor. If control voltage is not found at M3, check for voltage across terminals 95 & 96 of the BOR.If voltage exists, the BOR is openon overload. The BOR should be set to the auto reset position. The BOR must cool down in order to reset. If theBORwillnotreset,replacetheBOR.IftheBOR resets and M3 pulls in, but the indoor blower motor will still not run, refer to para. (a) for troubleshooting the line voltage supply circuit. If control voltage is not found at the BOR, trace the circuit back to the relay board and thermostat per the unit wiring diagram. Replace anydefective components.

2. Draft motor operates and furnace lights but supply air blower does not start after a short timedelay with room thermostat fan switch set to AUTO.

a. Set fan switch to ON. If blower motor runs, go to

Step f. If it does not, check to see if line voltage is being supplied to the contacts of the contactor (M3), and if the contactor is pulled in. Check for loose wiring.

b. If contactor (M3) is pulled in, proceed with the trou-

bleshooting steps indicated in Step 1 above.

c. If (M3) is pulled in and the blower motor still does

not run, replace the blower motor.

d. If (M3) is not pulled in, check for 24 volts at the (M3)

coil. If 24 volts is present, replace the (M3) contactor.

e. If 24 volts is not present at the (M3) coil, check for

loose 24 volt wiring back to the relay board. Check control wiring to the room thermostat. If all is fine, replace therelay board.

f. If the blower motor runs with the fan switch in the

ON position but does not run soon after the furnace

has ignited withthe fan switch in the AUTO position, check for loose 24 volt wiring between the relay board in the main control box, the Mate-N-Lok connector in the partition between the evaporator and gas heatsections and the time delayrelay (ETD).

g. If all control wiring is fine, check for 24 volts at the

relay board. If 24 volts is present, replace the relay board. If 24 volts is not present, replace the (ETD) relay.

The furnace may s hut itself down on a high tempera-

NOTE:

ture condition during the procedure, but this will not effect the test if it is donewithin 5 minutes of furnace shut-down.

3. The supply air bloweroperates but the draft motordoes not when the room thermostat is set to call for heat and the fan switch in the ON position.

a. The draft motor has inherent protection. If the motor

shell is hot to the touch, wait for the internal overload to reset.

b. If the m otor shell is cold with the room thermostat

calling for heat, check for line voltage at the motor's Mate-N-Lok connector attached to the evaporator partition. If line voltage is present, replace the draft motor.

c. If linevoltage isnot present, check forline voltage at

the heat relay (RW1) contacts in the main control box andcheck to see if the (RW1) is pulled in.

d. If the (RW1) relay is pulled in, check for a loose line

voltage connection.

e. If the (RW1) relay is not pulled in, check for 24 volts

at the (RW1) coil. If 24 volts is present, replace the (RW1) relay. If 24 volts is not present, check for a loose 24volt connection backto the relay board and check the connections from the room thermostat to the relay board. If all connections are correct, replace therelay board.

4. The draft motor runs but the furnace does not light and the sparker doesnot spark.

a. The ignition c ontrol (IC1, IC2) may be locked out

due to either a flame roll out or 100% shut off. These safety features are described above. If lock-out has occurred, 24V must be removed from the ignition controls. This is done at the unit or by resetting the room thermostat. After resetting 24V, check for proper furnace operation. If lock-out continues to occur, locate the source of the problem andcorrect.

b. Check all 24 volt connections from the relay board

to and in the gas heat section. Check low voltage connections to the (ETD) located in thecontrol box.

c. If the furnace is hot, it may be out on an over-tem-

perature condition, wait for limit reset.

Unitary Products 27

Page 28

d. If the furnace is cold, check for 24 volts at wire 241

attached to the time delay relay (ETD) located in the main control box.If 24 volts is not found,replace the ETD relay.

e. If 24 volts is found at wire 241, remove the wires

attachedtothe(ETD)andwithaVOM,checkfor continuity across contacts 1 and 2. If none is found, the (ETD) is open and must be replaced. If there is continuity, re-attach the wires.With the draft motor running, check for 24 volts at terminal 4 of (RW1-2) and (RW2-1). If 24 volts is not present, the centrifugal switch (CS) has not closed or has gone bad. Check the line voltage to the unit - if it is correct, replace the draft motor. If line voltage is low, call the power company.

f. Check for 24V at terminal 2 of (RW1-2 and RW2-1).

If 24V is not present, check for 24V at (RW1 and RW2) relay coils. If these relays are pulled in, then check for a loose connectionat terminal 2and terminal 4 of each relay. If no problem is found, then replace (RW1 and/or RW2) as required.

g. If 24 volts is present at the ignitor controls, check all

control wiring at the ignitor controls and the high tension wire to the ignitors. Check that the ground wires from the ignitor controls, the gas valves and pilot burners are all intact and making good electrical connection. Check to make sure that the ceramic insulator on the pilot ignitors or sensors is not broken or cracked, if all are intact, replace the ignition control IC1 or IC2.

5. The draft motor runs and the sparker sparks at the pilot burner but the pilot does notignite and agas odor is not detected atthe draft motor outlet.

a. Check to make sure gas is being supplied to the

unit. Make sure that the gas pressure to the unit is within the proper limits as described in the POST START CHECK LIST and that the pilot adjust screw is allowing some flow of gas as described in PILOT CHECKOUT.

b. Check all wiring between the ignitor control and the

gas valve. Check to make sure the ground connections areintact.

c. If the wiring is intact, check for 24volts across termi-

nals PV and COMMON on the ignitor control. If 24 volts is not present, replace the ignitor control.

d. If 24 volts is present, remove the pilot burner and

remove the pilotorifice fromthe pilotburner. Theorifice is removed in the direction opposite the flow of gas. Inspect the orifice for obstruction. If it is clear, replace the main gas valve.

6. The sparker sparks at the pilot burner but the pilot does not igniteand a gasodor is detected at the draft motor outlet.

a. Adjust the pilot adjust screw on the gas valve as

described in PILOT CHECKOUT.

b. Check the supply pressure as described in POST

START CHECK LIST. Make adjustments as necessary.

c. Check thepilot orificefor obstructionas describedin

para. 5d. Clean as needed but the problem should not be the gas valve.

7. The pilot burner ignites but the sparker continues to spark and the main burners donot ignite.

a. Make the same checks and adjustment as

described in para. 6.

b. Make sure that the pilot burner is not bent or dam-

aged.

c. Make sure that the ground connections at the pilot

burner, gas valve and ignitor control are intact. Check the high tension wire for good electrical connection. If all are intact, replace the ignitor module.

8. The pilot burner lights and the spark stops but themain burners donot light.

a. Check electrical c onnections between the ignitor

control and the gas valve. If intact, check for 24 volts across terminals MV and COMMON terminals. If no voltage detected, replace ignitor control. If voltage is present, replace gas valve.

9. Furnace lights with roll-out or one burner has delayed ignition.

a. Make sure that the pilot burner is aligned properly

with the carryover as described in PILOT CHECKOUT.

b. Make sure that the carry overs on adjoining burners

are screwed fast and are level with respect to one another.

10. Main burners light butexhibit erratic flame characteristics.

a. Adjust air shutters as described in BURNER AIR

SHUTTER ADJUSTMENT.

b. Check the main burner orifices for obstruction and

alignment. Removal procedure is described in BURNER INSTRUCTIONS. Clean or replace burner orifices and burners as needed.

Unitary 5005 Norman Products York OK Group Drive 73069

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