Greenheck ERT Installation Manual

Document 460945

Model ERT

Energy Recovery Ventilator with Tempering

Installation, Operation and Maintenance Manual

Please read and save these instructions for future reference. Read carefully before attempting to assemble, install, operate or maintain the product described. Protect yourself and others by observing all safety information. Failure to comply with instructions could result in personal injury and/or property damage!

General Safety Information

Only qualiﬁed personnel should install this system. Personnel should have a clear understanding of these instructions and should be aware of general safety precautions. Improper installation can result in electric shock, possible injury due to coming in contact with moving parts, as well as other potential hazards, including environmental. Other considerations may be required if high winds or seismic activity are present. If more information is needed, contact a licensed professional engineer before moving forward.

1. Follow all local electrical and safety codes, as well as the National Electrical Code (NEC), the National Fire Protection Agency (NFPA), where applicable. Follow the Canadian Electrical Code (CE) in Canada.

2. All moving parts must be free to rotate without striking or rubbing any stationary objects.

3. Unit must be securely and adequately grounded.

4. Do not spin fan wheel faster than maximum cataloged fan RPM. Adjustments to fan speed signiﬁcantly affect motor load. If the fan RPM is changed, the motor current should be checked to make sure it is not exceeding the motor nameplate amps.

5. Verify that the power source is compatible with the equipment.

6. Never open access doors to the unit while it is running.

DANGER

Always disconnect power before working on or near this equipment. Lock and tag the disconnect switch or breaker to prevent accidental power up.

CAUTION

When servicing the unit, the internal components may be hot enough to cause pain or injury. Allow time for cooling before servicing.

WARNING

The roof lining contains high voltage wiring. To prevent electrocution, do not puncture the interior or exterior panels of the roof.

Energy Recovery Ventilator with Tempering 1

Table of Contents

General Safety Information ...................1

Receiving, Handling and Storage ..............3

Product Overview ...........................4

Optional Subassemblies ......................4

Installation

Unit Dimensions and Weights ..................5

Curb Outside Dimensions, Recommended

Roof Openings and Curb Weights .............5

Service Clearances and Access Locations ........6

Handling ...................................6

Lifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Roof Curb Mounting .........................7

Optional Piping Vestibule ......................8

Rail Mounting/Layout .........................8

Duct Connections ...........................9

Electrical Installation

Procedure .................................10

Field-Provided Disconnect ....................11

Discharge Air Temperature Sensor .............11

Typical Control Center Components ............11

Optional Accessory Wiring Schematics ..........12

Piping Installation

Optional Coil Piping .........................13

Condensate Drain Trap ......................13

Unit Overview

Basic Unit .................................14

Optional Component Overview

Economizer ...............................14

Frost Control ..............................15

Variable Frequency Drive .....................15

CO2 Sensor ...............................15

Rotation Sensor ............................15

Dirty Filter Sensor ..........................15

Microprocessor Control ......................15

Unoccupied Recirculation Damper .............16

Service Outlet ..............................16

Vapor Tight Lights ..........................16

Outdoor Airflow Monitor .....................16

Smoke Detector ............................16

Start-Up

Warnings .................................17

Special Tools Required ......................17

Start-Up Procedure .........................17

Voltage Imbalance ..........................17

Pre-Start-Up Checklist .......................18

Start-Up Checklist ..........................18

Optional Accessories Checklist ................19

Start-Up Components

Energy Wheel ..............................20

Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-21

Vibration ..................................21

Optional Start-Up Components

Dirty Filter Switch ...........................22

Economizer ............................22-23

Frost Control ..............................23

Outdoor Airflow Monitor .....................24

Variable Frequency Drives ................

25-26

Routine Maintenance

Maintenance Frequency ......................27

Maintenance Procedures

Lubrication ..............................28

Dampers ................................28

Fan Belts ...............................28

Fan Motors ..............................28

Fan Wheel & Fasteners ....................28

Bearings ................................28

Internal Filter ............................29

External Filter ............................29

Coils ...................................29

Door Seals ..............................29

Energy Wheel ............................30

Troubleshooting

Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Energy Wheel ..............................32

Controller Alarms ...........................33

Rotation Sensor ............................33

Economizer ...............................33

Maintenance Log ........................34-35

Our Commitment ....................Backcover

Energy Recovery Ventilator with Tempering

Receiving

Upon receiving the product, check to ensure all items are accounted for by referencing the delivery receipt or packing list. Inspect each crate or carton for shipping damage before accepting delivery. Alert the carrier of any damage detected. The customer will make a notation of damage (or shortage of items) on the delivery receipt and all copies of the bill of lading which is countersigned by the delivering carrier. If damaged, immediately contact your Greenheck Representative. Any physical damage to the unit after acceptance is not the responsibility of Greenheck Fan Corporation.

Unpacking

Verify that all required parts and the correct quantity of each item have been received. If any items are missing, report shortages to your local representative to arrange for obtaining missing parts. Sometimes it is not possible that all items for the unit be shipped together due to availability of transportation and truck space. Conﬁrmation of shipment(s) must be limited to only items on the bill of lading.

Handling

Units are to be rigged and moved by the lifting brackets provided or by the skid when a forklift is used. Location of brackets varies by model and size. Handle in such a manner as to keep from scratching or chipping the coating. Damaged ﬁnish may reduce ability of unit to resist corrosion.

Storage

Units are protected against damage during shipment. If the unit cannot be installed and operated immediately, precautions need to be taken to prevent deterioration of the unit during storage. The user assumes responsibility of the unit and accessories while in storage. The manufacturer will not be responsible for damage during storage. These suggestions are provided solely as a convenience to the user.

INDOOR — The ideal environment for the storage of

units and accessories is indoors, above grade, in a low humidity atmosphere which is sealed to prevent the entry of blowing dust, rain, or snow. Temperatures should be evenly maintained between 30°F (-1°C) and 110°F (43°C) (wide temperature swings may cause condensation and “sweating” of metal parts). All accessories must be stored indoors in a clean, dry atmosphere.

Remove any accumulations of dirt, water, ice, or snow and wipe dry before moving to indoor storage. To avoid “sweating” of metal parts allow cold parts to reach room temperature. To dry parts and packages use a portable electric heater to get rid of any moisture build up. Leave coverings loose to permit air circulation and to allow for periodic inspection.

The unit should be stored at least 3½ in. (89 mm) off the ﬂoor on wooden blocks covered with moisture proof paper or polyethylene sheathing. Aisles between parts and along all walls should be provided to permit air circulation and space for inspection.

OUTDOOR — Units designed for outdoor applications

may be stored outdoors, if absolutely necessary. Roads or aisles for portable cranes and hauling equipment are needed.

The fan should be placed on a level surface to prevent water from leaking into the unit. The unit should be elevated on an adequate number of wooden blocks so that it is above water and snow levels and has enough blocking to prevent it from settling into soft ground. Locate parts far enough apart to permit air circulation, sunlight, and space for periodic inspection. To minimize water accumulation, place all unit parts on blocking supports so that rain water will run off.

Do not cover parts with plastic ﬁlm or tarps as these cause condensation of moisture from the air passing through heating and cooling cycles.

Inspection and Maintenance during Storage

While in storage, inspect fans once per month. Keep a record of inspection and maintenance performed.

If moisture or dirt accumulations are found on parts, the source should be located and eliminated. At each inspection, rotate the fan wheel by hand ten to ﬁfteen revolutions to distribute lubricant on motor. Every three months, the fan motor should be energized. If paint deterioration begins, consideration should be given to touch-up or repainting. Fans with special coatings may require special techniques for touch-up or repair.

Machined parts coated with rust preventive should be restored to good condition promptly if signs of rust occur. Immediately remove the original rust preventive coating with petroleum solvent and clean with lint-free cloths. Polish any remaining rust from surface with crocus cloth or ﬁne emery paper and oil. Do not destroy the continuity of the surfaces. Wipe thoroughly clean with Tectyl hard to reach internal surfaces or for occasional use, consider using Tectyl or the equivalent.

REMOVING FROM STORAGE — As units are removed

from storage to be installed in their ﬁnal location, they should be protected and maintained in a similar fashion, until the equipment goes into operation.

Prior to installing the unit and system components, inspect the unit assembly to make sure it is in working order.

1. Check all fasteners, set screws on the fan, wheel, bearings, drive, motor base, and accessories for tightness.

2. Rotate the fan wheel(s) by hand and assure no parts are rubbing.

506 (Ashland Inc.) or the equivalent. For

511M Rust Preventive or WD-40®

Energy Recovery Ventilator with Tempering

Product Overview

The model ERT combines the beneﬁts of energy recovery, wrap-around heat pipe, cooling coil and optional heating sources. Heating sources include electric, hot water. Cooling sources include split direct expansion and chilled water. This product is speciﬁcally designed to process 100% outdoor air to desired supply conditions. Three housing sizes provide airﬂow capacities from 2,000 to 10,000 cfm with external static pressures up to 1.75 in. wg.

Optional Subassemblies

Dampers

There are four locations where dampers can be installed. Low leakage or insulated low leakage motorized dampers can be added in the outdoor airstream and/or return airstream. An unoccupied recirculating air damper is also available. A backdraft damper is standard in the exhaust hood.

BACKDRAFT

EXHAUST DAMPER

TWO-INCH THICK MERV 8

PLEATED FILTERS

MOTORIZED RETURN

COIL

HEATPIPE

AIR DAMPER

INTAKE DAMPER

COIL

HEATING

CONTROL

CENTER

RETURN AIR

PERMANENT

ALUMINUM

MESH FILTERS

OUTDOOR AIR

WEATHERHOOD

EXHAUST AIR

WEATHERHOOD

DAMPER

WHEEL CASSETTE

SUPPLY FILTERS

EXHAUST FILTERS

HEATPIPE

COOLING

Split DX

The unit is equipped with an evaporator coil that will be connected to a separate condensing unit (provided by others). Depending on controlling options, the condensing unit will be controlled by others or an integral unit microprocessor controller. Piping components such as thermostatic expansion valve, ﬁlter drier, sight glass, etc., shall be ﬁeld-provided.

Electric Post-Heaters

The optional post-heater is used as a heat source for the building and is integrated into the supply airstream.

A temperature sensor (with a ﬁeld-adjustable set point) is mounted in the supply airstream after the post-heater to turn the post-heater on. A SCR heater allows for an inﬁnite amount of modulating control of the heat to provide an accurate discharge temperature during the call for heat.

As standard, the post-heater control panel is not single point wired to the unit control center. Separate power must be supplied to the post-heater disconnect (located in unit control center). Electric heaters are available in 208, 230, 460, or 575 VAC (refer to heater nameplate for voltage).

Outdoor Air Weatherhood

Outdoor air weatherhood will be factory-mounted.

Exhaust Air Weatherhood

The exhaust weatherhood is shipped separately as a kit with its own instructions. Backdraft dampers are always included as an integral part of the exhaust hood assemblies.

MOTORIZED RECIRCULATING

MOTORIZED OUTDOOR

AIR DAMPER

TWO-INCH THICK MERV 8 OR MERV

AIR DAMPER

8 AND 13 PLEATED FILTERS

Filters

There is the option of either two-inch thick MERV 8 or MERV 8 and 13 pre-ﬁlters in the outdoor airstream and MERV 8 ﬁlters in the exhaust airstream. There are also permanent washable aluminum mesh ﬁlters in the optional weatherhood.

Hot Water / Chilled Water Coils

Water coils can be used for a single purpose such as heating or cooling, or their function can be alternated between heating and cooling by changing the temperature of the water ﬂowing through the coil. Depending on the application, it may be necessary to use a glycol mixture to prevent the liquid from freezing. The water coils are engineered to operate at pressures up to 250 PSIG and temperatures up to 300°F, but ancillary equipment such as valves and pumps will often dictate lower operating temperatures. All water coils are pressure tested at the factory with 450 PSIG of dry nitrogen.

Energy Recovery Ventilator with Tempering

Installation

Unit Dimensions and Weights

Model Length Width Height

Exhaust

Hood

ERT-45 119.3 64.4 70.2 20.7 21.7 3100

ERT-55 133.5 75.2 71 23.6 21.7 3625

ERT-90 151.5 94.5 89 25.5 26.7 5800

All dimensions are in inches. Unit weights assume rooftop configuration with weatherhood, filters, outdoor air damper, cooling options, including but not limited to a six row dx coil, and heating options (where applicable). The approximate weight (lbs) is assuming all possible accessories are added per housing and may vary by 10% depending on unit.

Curb Outside Dimensions, Recommended Roof Openings and Curb Weights

Outdoor Air

Hood

Approximate Weight

(lbs)

Curb Weight

with Piping

Vestibule

Model

Outside

Curb

Dimensions

Recommended

Roof

Openings

Optional

Piping

Vestibule

Length Width A B C D

12 inch

Curb

Weight

12 inch Curb

Weight

with Piping

Vestibule

Curb weight

only

Adder per inch

ERT-45 114.9 60 31.8 54.8 48.1 32.8 195 228 +9.5 +11.4

ERT-55 129.1 70.8 38.3 63.5 54.8 32.8 228 260 +10.9 +12.7

ERT-90 147.1 90.1 39.1 79.4 64.1 32.8 291 323 +13.1 +14.9

All dimensions are in inches. All weights are in pounds. Various curb heights are available; use the adder per inch column to determine the weights above 12 inches.

RETURN AIR

INTAKE

SUPPLY AIR DISCHARGE

1-inch Foam Insulation

Curb Duct

Adaptor

1.9 inches

1/2 inch

Curb

Unit Base

1.63

inches

1 inch

Curb

Height

Roof Curb Detail

Energy Recovery Ventilator with Tempering

Service Clearances / Access Panel

Units require minimum clearances for access on all sides for routine maintenance. Filter replacement, drain pan inspection and cleaning, energy wheel cassette inspection, fan bearing lubrication and belt adjustment are examples of routine maintenance that must be performed. Blower and motor assemblies, energy recovery wheel cassette, coil and ﬁlter sections are always provided with a service door or panel for proper component access.

Model A (in.) B (in.) ERT-45 48 36 ERT-55 64 42 ERT-90 42 42

CENTER

ACCESS DOOR

EXHAUST AIR

WEATHERHOOD

ACCESS DOOR

CASSETTE REMOVAL

WHEEL CASSETTE

ACCESS DOOR

EXHAUST FILTERS

ACCESS DOOR

CONTROL

RETURN AIR

INTAKE

OUTDOOR AIR

WEATHERHOOD

DAMPER

SUPPLY FILTERS

HEATPIPE

ACCESS PANEL

ACCESS DOOR

COIL

COOLING

HEATPIPE

COIL

HEATING

ACCESS DOOR

Handling

While this unit was constructed with quality and dependability in mind, damage still may occur during handling of the unit for installation.

The system design and installation should follow accepted industry practice, such as described in the ASHRAE Handbook. Adequate space should be left around the unit for piping coils and drains, ﬁlter replacement, and maintenance. Sufﬁcient space should be provided on the side of the unit for routine service and component removal should that become necessary.

Energy Recovery Ventilator with Tempering

Lifting

WARNING

All factory-provided lifting lugs must be used when lifting the units. Failure to comply with this safety precaution could result in property damage, serious injury, or death.

1. Before lifting, be sure that all shipping material has been removed from unit.

2. To assist in determining rigging requirements, weights are provided in the Installation, Unit Dimensions and Weights section of this manual.

3. Unit must be lifted by all lifting lugs provided on base structure.

4. Rigger to use suitable mating hardware to attach to unit lifting lugs.

5. Spreader bar(s) must span the unit to prevent damage to the cabinet by the lift cables.

6. Always test-lift the unit to check for proper balance and rigging before hoisting to desired location.

7. Never lift units by weatherhoods.

8. Never lift units in windy conditions.

9. Preparation of curb and roof openings should be completed prior to lifting unit to the roof.

10. Check to be sure that gasketing (supplied by others) has been applied to the curb prior to lifting the unit and setting on curb.

11. Do not use fork lifts for handling unit.

NOTE

Install and caulk covers over lift points after unit is installed to ensure weatherization.

Roof Curb Mounting

Rooftop units require curbs to be mounted ﬁrst. The duct connections must be located so they will be clear of structural members of the building.

Position the unit roof opening such that the supply discharge and exhaust inlet of the unit will line up with the corresponding ductwork. Be sure to allow for the recommended service clearances when positioning opening.

Do not face the outdoor air intake of the unit into prevailing wind and keep the intake away from any other exhaust fans. Likewise, position the exhaust discharge opening away from outdoor air intakes of any other equipment.

1. Factory-Supplied Roof Curbs Roof curbs are Model GKD, which are shipped in a knockdown kit (includes duct adapter) and require ﬁeld assembly (by others). Assembly instructions are included with the curb.

2. Install Curb Locate curb over roof opening and fasten in place. Reference Installation, Curb Outside Dimensions, Recommended Roof Openings and Weights in this manual. Check that the diagonal dimensions are within ±1/8 inch of each other and adjust as necessary. For proper coil drainage and unit operation, it is important that the installation be level. Shim as required to level.

3. Install Ductwork Installation of all ducts should be done in accordance with SMACNA and AMCA guidelines. Duct adapter provided to support ducts prior to setting the unit.

4. Set the Unit Lift unit to a point directly above the curb and duct openings. Guide unit while lowering to align with duct openings. Roof curbs ﬁt inside the unit base. Make sure the unit is properly seated on the curb and is level. Gasketing (by others) needs to be installed to curb creating a seal between the ductwork and the base of the unit.

Energy Recovery Ventilator with Tempering

Optional Piping Vestibule

Insulated enclosure that is mounted externally to the unit in order to protect the water supply and return piping. Not available in models with water-source heat pump or evaporative cooling.

Supply Blower Access Door

Drain Pan Connection

Exhaust Blower Access Door

Outdoor Air Weatherhood

Cassette/Filter Access Door

Piping Vestibule

Rail Mounting / Layout

1. Rails designed to handle the weight of the unit should be positioned as shown on the diagram (rails by others).

2. Make sure that rail positioning does not interfere with the supply air discharge opening or the exhaust air intake opening on the unit. Avoid area dimensioned “B” below.

3. Rails should run the width of the unit and extend beyond the unit a minimum of 12 inches on each side.

4. Set unit on rails.

Cooling Coil (with or without heating)

Exhaust Blower Access Door

Outdoor Air Weatherhood

Heating Only

Unit Size Weight

ERT-45 235

ERT-55 235

ERT-90 280

All weights are in pounds.

Cassette/Filter Access Door

Supply Blower Access Door

Piping Vestibule

Rail Mounting

Unit Size A B

ERT-45 7.0 41.9

ERT-55 5.5 53.0

ERT-90 6.0 59.0

All dimensions are in inches.

Energy Recovery Ventilator with Tempering

Ductwork Connections

POOR

Examples of poor and good fan-to-duct connections are shown. Airﬂow out of the fan should be directed straight or curve the same direction as the fan wheel rotates. Poor duct installation will result in low airﬂow and other system effects.

Length of Straight Duct

GOOD

Inlet/Outlet Descriptions

Code Description Code Description

OIE Outdoor Air Intake End SDT Supply Discharge Top

OIT Outdoor Air Intake Top SDT/IG Supply Discharge Top w/IG

RIE Return Air Intake End SDS Supply Discharge Side

RIS Return Air Intake Side SDB Supply Discharge Bottom

RIB Return Air Intake Bottom EDE Exhaust Discharge End

RIT Return Air Intake Top EDT Exhaust Discharge Top

SDE Supply Discharge End EDS Exhaust Discharge Side

ERT-45

Recommended

Duct Size

Intake Duct Size Discharge 12-12 Blower

OIE 28 x 36 SDE 20 x 20

OIT 34 x 24 SDS 20 x 20

RIE 24 x 40 SDT 20 x 20

RIS 26 x 32 SDT/IG 28 x 28

RIB 20 x 48 SDB 16 x 18

RIT 28 x 30 EDE 20 x 20

EDT 20 x 20

EDS 20 x 20

ERT-55

Recommended

Duct Size

Intake Duct Size Discharge 15-15 Blower

OIE 32 x 52 SDE 28 x 28

OIT 40 x 28 SDS 28 x 28

RIE 30 x 40 SDT 28 x 28

RIS 30 x 38 SDT/IG 38 x 30

RIB 20 x 54 SDB 18 x 20

RIT 30 x 40 EDE 28 x 28

EDT 28 x 28

EDS 28 x 28

ERT-90

Recommended

Duct Size

Intake Duct Size Discharge 18-18 Blower

OIE 34 x 64 SDE 32 x 32

OIT 34 x 50 SDS 32 x 32

RIE 32 x 60 SDT 32 x 32

RIS 40 x 40 SDT/IG 34 x 33

RIB 22 x 74 SDB 20 x 24

RIT 40 x 40 EDE 32 x 32

EDT 32 x 32

EDS 32 x 32

All dimensions shown in inches.

• Recommended duct sizes are based on velocities across the cfm range of each model at approximately 800 feet per minute (FPM) at minimum airflow and up to 1600 fpm at maximum airflow.

• Recommended duct sizes are only intended to be a guide and may not satisfy the requirements of the project. Refer to plans for appropriate job specific duct size and/or velocity limitations.

Energy Recovery Ventilator with Tempering

Electrical Installation

WARNING

The roof lining contains high voltage wiring. To prevent electrocution, do not puncture the interior or exterior panels of the roof.

WARNING

To prevent injury or death due to electrocution or contact with moving parts, lock disconnect switch open.

IMPORTANT

Before connecting power to the unit, read and understand the following instructions and wiring diagrams. Complete wiring diagrams are attached on the inside of the control center door(s).

IMPORTANT

All wiring should be done in accordance with the latest edition of the National Electrical Code ANSI/NFPA70 and any local codes that may apply. In Canada, wiring should be done in accordance with the Canadian Electrical Code.

IMPORTANT

The equipment must be properly grounded and bonded. Any wiring running through the unit in the airstream must be protected by metal conduit, metal clad cable or raceways.

CAUTION

If replacement wire is required, it must have a temperature rating of at least 105°C, except for an energy cut-off or sensor lead wire which must be rated to 150°C.

DANGER

High voltage electrical input is needed for this equipment. This work should be performed by a qualified electrician.

CAUTION

Any wiring deviations may result in personal injury or property damage. Manufacturer is not responsible for any damage to, or failure of the unit caused by incorrect final wiring.

WARNING

If unit is equipped with a microprocessor, terminals Y1, Y2 and W1 cannot be wired to a thermostat. Wiring to these terminals will bypass unit’s internal safeties.

1. Determine the Size of the Main Power Lines The unit’s nameplate states the voltage and the unit’s MCA. The main power lines to the unit should be sized accordingly. The nameplate is located on the outside of the unit on the control panel side.

2. Determine the Size of Electric Heater Wiring

An optional electric heater may require a separate power supply. The power connection should be made to the factory-provided electric heater disconnect and must be compatible with the ratings on the nameplate, supply power voltage, phase and amperage. Consult ANSI/NFPA 70 and CSA C22.1 for proper conductor sizing.

3. Provide the Opening(s) for the Electrical Connections

Electrical openings vary by unit size and arrangement and are ﬁeld-supplied.

4. Connect the Power Supplies Connect the main power lines and electric heater power lines to the disconnect switches or terminal blocks and main grounding lug(s). Torque ﬁeld connections to manufacturer’s recommendations.

5. Wire the Optional Convenience Outlet The convenience outlet requires a separate 115V power supply circuit. The circuit must include short circuit protection which may need to be supplied by others.

6. Connect Field-Wired Low Voltage Components Most factory-supplied electrical components are prewired. To determine what electrical accessories require additional ﬁeld-wiring, refer to the unitspeciﬁc wiring diagram located on the inside of the control center access door.

Control wires should not be run inside the same conduit as that carrying the supply power. Make sure that ﬁeld-supplied conduit does not interfere with access panel operation. All low voltage wiring should be run in conduit wherever it may be exposed to the weather.

The low voltage control circuit is 24 VAC and control wiring should not exceed 0.75 ohms. If wire resistance exceeds 0.75 ohms, an isolation relay should be added to the unit control center and wired in place of the remote switch (typically between terminal blocks R and G on the terminal strip. The relay must be rated for at least 5 amps and have a 24 VAC coil. Failure to comply with these guidelines may cause motor starters to “chatter” or not pull in which can cause contactor failures and/or motor failures.

Energy Recovery Ventilator with Tempering

Field-Provided Disconnect

If ﬁeld-installing an additional disconnect switch, it is recommended that there is at least four feet of service room between the switch and system access panels. When providing or replacing fuses in a fusible disconnect, use dual element time delay fuses and size according to the rating plate.

Discharge Air Temperature Sensor

The discharge air temperature sensor is factory-mounted in the blower discharge section of the unit behind the blower cut off plate.

Typical Control Center Components with Microprocessor Control

11 14

Individual components and locations will vary.

1. Main disconnect (non-fusible, lockable)

2. Motor starter - outdoor air fan

3. Motor starter - exhaust air fan

4. Motor contactor - energy wheel

5. 24 VAC control transformer

6. 24 VAC terminal strip

7. Fuses for blower motors

8. Grounding lug

9. Distribution block

10. Terminal block

Optional Components

11. Microprocessor controller

12. Dirty ﬁlter pressure switches

13. Economizer module

14. Thermostats for

• Economizer module

• Energy recovery wheel frost control

15. GreenTrol®

16. Frost control pressure switch

17. Energy recovery wheel VFD

Energy Recovery Ventilator with Tempering

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