Greenheck ERCH-20 Installation Manual

Download

Page 1

READ AND SAVE THESE INSTRUCTIONS

ENERGY RECOVERY UNIT

PART #468151

Model ERCH-20, 45, 55 & 90

without DDC Controls

INSTALLATION, OPERATION AND MAINTENANCE MANUAL

RECEIVING AND HANDLING

The ERCH is thoroughly inspected and test run at the factory. However, damage may occur

during shipping and handling. Upon delivery, inspect the unit for both obvious and hidden

damage. If damage is found, record all necessary information on the bill of lading and file a claim

with the final carrier. In addition, ensure all accessory items are present. Some accessory items

are stored inside the unit during shipping.

SAFETY WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage,

injury or death. Read this installation, operation, and maintenance manual thoroughly before

installing or servicing this equipment. Installation and service must be performed by a qualified

installer, service agency, or the gas supplier.

WITH PACKAGED DX

INSTALLATION SUPPLEMENTS

Refer to the following installation supplements

ERCH supplied with Indirect Gas (IG) heating:

Model PVF, Indirect Gas Fired Furnaces

for Energy Recovery Units, Part #461006

ERCH Curb Assembly Instruction, Part #468280

SAVE THIS MANUAL

This manual is the property of the

owner, and is required for future

maintenance. This manual should

remain with each ERCH unit when the

job is complete.

Page 2

TABLE OF CONTENTS

Storage and Owners Information ..........2

Basic Operation..........................3

Installation

Lifting .................................4

Unit Weights & Recommended Roof

Openings ............................4

Installation Concerns .....................5

Roof Curb Mounting ...................5-6

Rail Mounting and Ductwork Connections....6

Electrical Information.................. 7-8

Control Center Components ...............8

Service Clearances ......................9

Dimensional Data/Access Door Description . 10

Coil Applications & Drain Trap Info......11-12

Optional Accessories

Electric Heater Application/Operation ......13

Frost Control Application/Operation........14

Economizer Application/Operation .........15

Variable Frequency Drives ...............16

Typical Wiring Diagram ..................17

Sensors and Lights ..................18-19

Remote Control Panel & Wiring ........20-22

Sensors Mounted by Factory .............23

Energy Recovery Unit with Packaged DX

Start-Up Checklist

Unit ...............................24-26

Optional Accessories....................27

Fan ..................................28

Energy Recovery Wheel .................29

Routine Maintenance Checklist...........33

Belts and Motors .......................34

Blower Wheel and Fasteners .............34

Filters ................................35

Coil Maintenance ......................36

Energy Recovery Wheel Maintenance

Accessing Energy Recovery Wheel ........37

Removing Wheel Segments ..............37

Cleaning Wheel Segments ...............38

Parts List ..............................39

Sequence of Operation ...............40-41

Troubleshooting -Airflow .................42

Troubleshooting -General Unit .........43-44

Troubleshooting -Refrigeration Circuit ..45-50

Notes ..................................51

Warranty ...............................52

STORAGE

When a unit is not going to be in service for an extended amount of time, certain procedures should be followed to keep the fans in proper operating condition.

 •Rotatefanwheelmonthlyandpurgegreasefrombearingsonceeverythreemonths  •Coverunitwithtarptoprotectfromdirtandmoisture

(Note: do not use a black tarp as this will promote condensation)

 •Energizefanmotoronceeverythreemonths  •Storebeltsflattokeepthemfromwarpingandstretching  •Storeunitinlocationwhichdoesnothavevibration  •Afterstorageperiod,purgegreasefromfanbearingsbeforeputtingfanintoservice

If storage of unit is in a humid, dusty or corrosive atmosphere, rotate the fan and purge the bearings once a month. Improper storage which results in damage to the unit or components will void the warranty.

OWNER’S INFORMATION

The following summary highlights some important notes to help avoid premature failure and possible voidance of warranty.

Product Overview

Greenheck ERCH Models integrated with a complete refrigerant system are designed with the purpose of being a self-contained source for heating and cooling in both commercial and institutional applications. This is done in a highly efficient manner through the use of a total enthalpy recovery wheel. The wheel allows the compressors and cooling equipment to be downsized in the unit, therefore being more cost effective to operate. The DX system comes fully charged from the factory with refrigerant and is ready for installation upon arrival.

The smaller tonnage units (4-9 tons) contain a single compressor, allowing for one stage of cooling. Larger units (10-30 tons) come standard with two compressors. This allows for staging of compressors to meet a wider range of outdoor air loads while reducing the amount of cycles per compressor.

Integral Components

All units are provided with an expansion valve, hermetic scroll compressor(s), liquid line filter drier, high pressure manual reset cutout, low pressure auto-reset cutout, time delays for compressor protection, service/ charging valves, moisture indicating sight glass, and hot gas bypass. The compressors also come standard with a crankcase heater for additional protection.

Page 3

Energy Recovery Unit with Packaged DX

Shutdown Operation

The scroll compressors in this unit are designed to compress gas refrigerant only. To prevent liquid refrigerant from migrating into and damaging the compressors, each compressor is supplied with a crankcase heater. Prior to starting the compressors, the heaters must have power to them for 24 hours. Power should never be cut to these units unless the complete shutdown procedure is followed.

Proper shutdown procedure:

1) Turn off main power supply to the unit

2) Turn thermostat controls to “off” position

3) Restore main power supply to the unit

4) Wait 24 hours prior to turning the thermostat control to the “on” position

Low Ambient Operation

Low ambient operation can cause damage to the refrigerant system. A factory-installed temperature sensor in the outdoor air intake prevents refrigerant system operation at ambient conditions below 55ºF. Crankcase heaters will still be engaged provided the main power has not been disconnected. If cooling is desired at ambient temperatures below 55ºF, economizer operation (wheel start/stop or wheel modulation) should be employed.

Reduced Airflow – Pumping oil and liquid refrigerant

Lack of maintenance will lead to filters, condensing coils, and evaporator coils building up with dirt and debris. As this occurs, the airflow through the unit will decrease. Cooling coils are sized to handle a particular airflow volume. A reduction in airflow can cause the cooling coils to get too cold and may result in excessive liquid refrigerant return to the compressors. The liquid refrigerant buildup in the compressors will displace the necessary oil required for proper lubrication. The combination of these two events will significantly reduce the life of the compressors.

To maintain the proper airflow and system efficiency, follow all procedures in the Maintenance section.

Safety Listing

The ERCH units are listed per ANSI/UL 1995, Heating and Cooling Equipment, and bear the ETL logo.

Environmental Concerns

This equipment contains R22 or R-410a refrigerant. Refer to label on access door identifying the type of refrigerant in the unit.

R22 is a class II refrigerant that contains HCFC’s. If released, HCFC’s may reduce the amount of ozone in the atmosphere. This ozone depletion will result in less protection from the sun and therefore it is critical to use every precaution necessary to minimize the amount admitted to our environment.

When working with Greenheck’s fully charged refrigerant system, it is strongly recommended that caution is undertaken during installation, operation, and routine maintenance. This caution will help ensure that minimal amounts of refrigerant are leaked into the atmosphere. To comply to the U.S. Clean Air Act, anytime there is residual refrigerant, the proper equipment shall be used and methods should be followed to reclaim the refrigerant so that it can be recycled, reprocessed, or destroyed.

Do not release refrigerant to the

atmosphere! If required service

procedures include the adding or

removing of refrigerant, the service

technician must comply with all

federal, state and local laws. The

procedures discussed in this manual

should only be performed by a

qualified EPA Certified Technician.

IMPORTANT!

BASIC OPERATION

The ERCH with Packaged DX units bring in fresh, outdoor air and remove stale, exhaust air. Prior to discharging the exhaust air, the energy recovery wheel transfers energy from the exhaust air to the outdoor air at an efficiency of 70-80%. Simply put, this unit preconditions the outdoor air to save money on heating and cooling costs. These particular units also have packaged DX cooling and heating options available after the recovery wheel to further condition the fresh air.

Outdoor

Air

DX Cooling

Coil

Conditioned Air

sent to space

Energy Recovery Wheel

Optional

Heater

Exhaust Air

from building

Page 4

Energy Recovery Unit with Packaged DX

CAUTION!

Unit is designed for Outdoor installation only. Follow all guidelines in this manual for proper installation.

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.

See Service Clearances/Access Panel Locations section for more details.

SAFETY 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.

HANDLING

While this unit was constructed with quality and dependability in mind, damage still may occur during handling of the unit for installation. Exercise extreme caution to prevent any damage from occurring to the refrigerant system. This unit contains a system pressurized with refrigerant that if damaged, could leak into the atmosphere or cause bodily harm due to the extreme cold nature of expanding refrigerant. Use protective equipment such as gloves and safety glasses to minimize or prevent injury in case of a system leak during installation.

LIFTING

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

2) To assist in determining rigging requirements, weights are shown below.

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.

UNIT WEIGHTS & RECOMMENDED ROOF OPENING

Unit

Size ERCH-20 2150 46 46

ERCH-45 3500 54 48

ERCH-55 4450 65 58

ERCH-90 6200 85 63

Unit weights assume rooftop configuration with weatherhoods, filters, outdoor air damper, six row DX coil, integral condensing section and an indirect gas fired furnace.

Approximate

Weight (lbs)

(inches)V (inches)

Lift using lifting lugs

and spreader bar

EXHAUST

INTAKE

SUPPLY

DISCHARGE

1/2 inch

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 (see Service Clearances). 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.

Page 5

Energy Recovery Unit with Packaged DX

INSTALLATION CONCERNS

Unobstructed airflow to the condensing section must be maintained at all times to ensure proper operating efficiency and capacity of the cooling system. Unit placement should allow proper airflow over the condensing section. The unit may not operate properly and damage may occur to the system if there is coil starvation (lack of air over condenser) or warm air recirculating back through the condensing coil. Recirculating air is caused when the unit is placed near obstacles that can redirect exhaust air from the condensing fans, back around to the coil inlet. Overhangs or walls near the condensing section are two examples.

Another consideration when placing the unit is prevailing wind direction. The condensing coil operation can be significantly affected when winds are blowing continuously and directly at the condensing coil. On hot days, the wind will help the system by providing extra flow over the coil. But on cooler days, that same wind may overcool the refrigerant, and cause hot gas bypass to operate more frequently, causing higher operating costs. Therefore, avoiding direct winds will provide a more stable operation of the system throughout the cooling season.

Lack of air over the coil can reduce efficiencies and affect system operation. Do not allow debris (such as leaves and trash), to accumulate on or near the unit. Keeping debris clear of the unit will ensure minimal obstruction to the coils, keeping efficiencies and operation closer to design. The unit typically should not operate when snow is present. In the event this is possible, make sure all snow is clear of the coil and condensing fans prior to operating the unit.

If more than one unit is being installed, make provisions so discharge air from either the condensing fans or exhaust fan of the unit do not discharge towards another unit’s intake. Also, OA intake and condensing sections should be spaced as too allow proper airflow to each unit helping ensure the units operate as intended.

When cutting only duct openings, cut opening 1 inch (25mm) larger than duct size to allow clearance for installation. Area enclosed by roof curb must comply with clearance to combustible materials. If the roof is constructed of combustible materials, area within the roof curb must be ventilated, left open, or covered with non-combustible material which has an “R” value of at least 5. If area within curb is open, higher radiated sound levels may result.

Where the supply or warm air duct passes thru a combustible roof, a clearance of one inch must be maintained between the outside edges of the duct and combustible material in accordance with NFPA Standard 90A.

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.

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. (Refer to Recommended Roof Openings). 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.

Roof curb details, including

duct location dimensions, are

available on ERCH roof curb

assembly instructions,

Part #468280.

Curb Outside Dimensions and Curb Weights (lbs)

Model L W Weight

ERCH-20 104.88 51 310

ERCH-45 115.75 60.63 400

ERCH-55 129.88 71.5 510

ERCH-90 148.13 90.75 720

All dimensions shown are in inches. Weights are for 12 inch high curbs.

Curb Outside Dimensions

Page 6

Length of Straight Duct

GOOD

POOR

GOODPOOR

Tu rning

Vanes

GOODPOOR

Tu rning

Vanes

ROOF CURB MOUNTING - CONTINUED

SIDE OF UNIT

BASE

1 INCH INSULATION

ERCH-20 2.00 2.00 1.00 0.88 0.75

ERCH-45 2.00 4.25 2.00 1.31 0.50

ERCH-55 2.00 4.25 2.00 1.31 0.50

ERCH-90 2.00 4.25 2.00 1.31 0.50

ROOF CURB

All dimensions shown are in inches.

Curb Cap Details for Factory Supplied Roof Curbs

RAIL MOUNTING

Rail Layout

• RailsdesignedtohandletheweightoftheERCHshouldbe

positioned as shown on the diagram (rails by others).

• Makesurethatrailpositioningdoesnotinterferewiththesupply

air discharge opening or the exhaust air intake opening on the ERCH unit. (Avoid area dimensioned “B” below).

• Railsshouldrunthewidthoftheunitandextendbeyondtheunit

a minimum of 12 inches on each side.

• Setunitonrails.

Model

Energy Recovery Unit with Packaged DX

Curb Cap Dimensions

A B C D E

Isometric view of unit on rails

Rail

OUTDOOR AIR INTAKE HOOD

Model

Mounting

A B

SUPPLY/EXHAUST

OPENING

B A

Side view of unit on rails

DUCTWORK CONNECTIONS

Examples of good and poor fan-to-duct connections are shown below. Airflow out of the fan should be directed

ERCH-20 5.00 41.00

ERCH-45 7.00 41.90

ERCH-55 5.50 53.00

ERCH-90 6.00 59.00

All dimensions shown are in inches.

straight or curve the same direction as the fan wheel rotates. Poor duct installation will result in low airflow and other system effects.

Recommended Discharge Duct Size and Length

Model Blower Size Duct Size Straight Duct Length

ERCH-20 9 14 x 14 36

ERCH-45 12 20 x 20 48

ERCH-55 15 28 x 28 60

ERCH-90 18 32 x 32 60

All dimensions shown are 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.

• Straightductlengthswerecalculatedbasedon100%effectiveductlengthrequirementsasprescribedinAMCAPublication201.

Calculated values have been rounded up to nearest foot.

POOR

Page 7

Energy Recovery Unit with Packaged DX

OUTDOOR AIR WEATHERHOOD

Outdoor air weatherhood will be factory mounted.

EXHAUST WEATHERHOOD

The exhaust weatherhood is shipped separately as a kit with its own instructions.

DAMPERS

Backdraft dampers are always included as an integral part of the exhaust hood assemblies. Motorized outdoor air and exhaust air dampers are optional and are factory mounted (and wired) at the intake.

ELECTRICAL INFORMATION

The unit must be electrically grounded in accordance with the current National Electrical Code, ANSI/NFPA 70. In Canada, use current CSA Standard C22.1, Canadian Electrical Code, Part 1. In addition, the installer should be aware of any local ordinances or electrical company requirements that might apply. System power wiring must be properly fused and conform to the local and national electrical codes. System power wiring is to the unit main disconnect (door interlocking disconnect switch standard on most units) or distribution block and must be compatible with the ratings on the nameplate: supply power voltage, phase, and amperage (Minimum Circuit Amps - MCA, Maximum Overcurrent Protection - MOP). All wiring beyond this point has been done by the manufacturer and cannot be modified without affecting the unit’s agency / safety certification.

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.

Field Power Connection: Electronic wiring is run through the roof of the unit. All power and control connections should be run through the floor or side panel.

If power supply is desired through bottom of unit, run the wiring through the curb, cut a hole in the cabinet bottom, and wire to the disconnect switch. Seal penetration in cabinet bottom to prevent leakage.

The electric supply to the unit must meet stringent requirements for the system to operate properly. Voltage supply and voltage imbalance between phases should be within the following tolerances. If the power is not within these voltage tolerances, contact the power company prior to operating the system.

Voltage Supply - See voltage use range on the rating plate. Measure and record each supply leg voltage at all line disconnect switches. Readings must fall within the allowable range on the rating plate.

Voltage Imbalance - In a 3-phase system, excessive voltage imbalance between phases will cause motors to overheat and eventually fail. Maximum allowable imbalance is 2%. To determine voltage imbalance, use recorded voltage measurements in this formula.

Key: V1, V2, V3 = line voltages as measured

VA (average) = (V1 + V2 + V3) / 3

VD = Line voltage (V1, V2 or V3) that deviates farthest from average (VA)

Formula: % Voltage Imbalance = [100 x (VA-VD)] / VA

CAUTION

If any of the original wire as supplied with the appliance must be replaced, it must be

replaced with wiring material having a temperature rating of at least 105ºC.

WARNING

To prevent injury or death due to electrocution or

contact with moving parts, lock disconnect switch

open.

Most factory supplied electrical components are pre-wired. To determine what electrical accessories require additional field wiring, refer to the unit specific wiring diagram located on the inside of the unit control center access door. The low voltage control circuit is 24 Vac and control wiring should not exceed 0.75 ohms. Refer to Field Control Wiring Length/Gauge table for wire length maximums for a given wire gauge. 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.

For units with a gas furnace, if you turn off the

power supply, turn off the gas.

WARNING

Field Control Wiring Length/Gauge

Total Wire Length Minimum Wire Gauge

125 ft. 18 200 ft. 16 300 ft. 14 450 ft. 12

Page 8

Energy Recovery Unit with Packaged DX

If wire resistance exceeds 0.75 ohms, an industrial-style, plug-in 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 (refer to Typical Control Center Components). 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.

Note: Standard factory installed electric post-heaters have their own disconnect separate from the unit

disconnect. Thus, each electric post-heater requires its own separate power connection.

CONTROL CENTER COMPONENTS

1. Main Disconnect (non-fusible, lockable)

2. Motor Starter - Exhaust Air Fan

3. Motor Starter - Outdoor 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. Distributor block

10. Compressor fuse blocks

11. Compressor contactors

12. Condensing fan contactors

13. Compressor cycle timers

14. Compressor relay

15. Terminal block

Optional Control Center Components

16. DDC controller

17. Dirty filter pressure switches

18. Economizer module

19. Thermostats for:

- Economizer module

- Energy Recovery wheel frost control

- Compressor lock out

20. Terminal block

21. Frost control pressure switch

22. Energy recovery wheel VFD

1 5

Component #6

Exploded Detail

of Terminal Strip

Refer to “Refrigeration System” section for components in compressor

compartment

Access to Control Center

Components is gained through the access panel indicated.

Page 9

Energy Recovery Unit with Packaged DX

SERVICE CLEARANCES / ACCESS PANEL LOCATIONS FOR MODEL ERCH

Clearances must be maintained on all sides of this unit. This especially is true with the top of this unit. Hot air is being discharged through the condensing fans during operation, and the more clearance available, the better the chance of avoiding recirculation or coil starvation. This unit should never be placed under an overhang or inside a building. A minimum of 48 inches over the condensing fans is recommended.

ERCH-20, 45, 55, and 90 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. Clearances for component removal may be greater than the service clearances, refer to drawings for these dimensions.

ERCH-20 ERCH-45

36 IN

ACCESS PANEL

EXHAUST

HOOD

OUTDOOR AIR

FILTERS

36 IN

WHEEL CASSETTE

ACCESS PANEL

FILTERS

COIL

SECTION

ACCESS PANEL

ELECTRICAL BOX

EXHAUST AIR

INTAKE

ACCESS PANEL

IG HEATER

Minimum 48 inches clearance

Minimum 12 inches clearance

Condensing Coil Intake Keep this area clear

52 IN

CLEARANCE

WITH IG HEATER

12 IN

MINIMUM

ERCH-55 ERCH-90

ACCESS PANEL

*48 IN

ACCESS PANEL

**64 IN

ACCESS PANEL

Clearances for service and component removal on ERCH-20 and ERCH-45 * Clearance for energy wheel removal on ERCH-20 ** Clearance for energy wheel removal on ERCH-45

FILTERS

42 IN

ACCESS PANEL

WHEEL CASSETTE

FILTERS

COIL

SECTION

ACCESS PANEL

ELECTRICAL BOX

EXHAUST AIR

INTAKE

42 IN

ACCESS PANEL

WITH IG HEATER

IG HEATER

52 IN

CLEARANCE

42 IN

ACCESS PANEL

EXHAUST

HOOD

OUTDOOR AIR

12 IN

MINIMUM

Clearances for service and component removal on ERCH-55 and ERCH-90

Page 10

Energy Recovery Unit with Packaged DX

DIMENSIONAL DATA / ACCESS DOOR DESCRIPTIONS AND LOCATIONS

Model

A B C D E F G H I J

Exterior Dimensions

ERCH-20 108 50 56 27 28.5 17 6 14.25 18 18

ERCH-45 119 69 66 38 41 23.375 10.5 13.375 20 16

ERCH-55 133.5 70 76 39 59.5 5.875 7.125 21.25 25 16

ERCH-90 151.5 85 96 46 78 2.875 10 24.5 27 16

All dimensions shown are in inches.

Overall Exterior Dimensions

Model

(including Lifting Lugs)

Width

Overall Width

(with Exhaust Hood)

Overall Length

(with Outdoor Air Hood)

ERCH-20 59.5 75 116

ERCH-45 69.5 86 122

ERCH-55 79.5 101 134

ERCH-90 99.5 123 147

All dimensions shown are in inches.

Following is a list of items accessible through the access doors shown on the diagrams. Some items are optional and may not have been provided.

1. Exhaust blower, motor, and drives

2. Aluminum mesh filters (intake hood)

3. Energy recovery wheel, motor, belt, and seals Outdoor air filters Outdoor air intake damper (optional) Electric preheater (optional) Frost control sensors (optional) Economizer sensors (optional)

4. Coil access / Drain pan 5a. Outdoor air blower, motor, and drives (with indirect gas furnace)

6. Control center All electrical controls VFD for energy recovery wheel (optional)

7. Exhaust air filters Exhaust air intake damper (optional)

8. Electric post-heater control center (optional)

9. Bypass damper (optional)

10. Condensing fan motors

11. Compressor(s) - refer to Refrigeration System section for components in compressor

compartment Drain Pan 5b. Outdoor air blower, motor, and drives (without indirect gas furnace) Coil access / Drain pan (w/o Electric Heat)

Model ERCH with Packaged DX

Page 11

Energy Recovery Unit with Packaged DX

COIL APPLICATION RECOMMENDATIONS

Factory installed cooling and heating components are mounted in the coil section of the unit. The coil section is downstream of the energy wheel on the supply air side of the unit.

Note the coil connection locations on the picture. Coil connections are located external to the unit as shown. Coil connections that are not external have been ordered from the factory with interior or exhaust airstream coil connections.

Hot

water coil

connections

Coil access door

Note: DX coil liquid connection is internal to units.

WATER COILS

1. Piping should be in accordance with accepted industry standards. Pipework should be supported independently of the coils. Water connections are male NPT iron pipe. When installing couplings, do not apply undue stress to the connection extending through the unit. Use a backup pipe wrench to avoid breaking the weld between coil connection and header.

2. Connect the WATER SUPPLY TO THE BOTTOM CONNECTION on the air leaving side and the WATER RETURN TO THE TOP CONNECTION on the air entering side. To insure proper venting, an external air vent in the piping is recommended. Connecting the supply and/or return in any other manner will result in very poor performance. Be sure to replace factory installed grommets around coil connections if removed for piping. Failure to replace grommets will result in water leakage into the unit and altered performance.

3. The air vent at the uppermost point should be temporarily opened during system start-up to release all of the air from the coil. To maintain heat transfer capacity, periodically vent any air in coil.

4. Water coils are not normally recommended for use with entering air temperatures below 40ºF; however, the energy recovery wheel maintains a pre-coil temperature higher than 40ºF. No control system can be depended on to be 100% safe against freeze-up with water coils. Glycol solutions or brines are the only safe media for operation of water coils with low entering air conditions.

CONTINUOUS WATER CIRCULATION THROUGH THE COIL AT ALL TIMES IS HIGHLY RECOMMENDED.

5. Pipe sizes for the system must be selected on the basis of the head (pressure) available from the circulation pump. The velocity should not exceed 6 feet per second and the friction loss should be approximately 3 feet of water column per 100 feet of pipe.

DIRECT EXPANSION (DX) COILS WITH INTEGRAL CONDENSING SECTION

1. The condensate drain pipe should be sized adequately to ensure the condensate drains properly. Refer to Drain Trap section.

Page 12

Energy Recovery Unit with Packaged DX

DRAIN TRAP

Cooling coils are provided with a stainless steel drain pan with 1-inch male NPT drain connection. A drain trap must be connected to the drain connection to allow excess water to flow out of the drain pan. More importantly, though, due to the negative internal static of the cooling coil compartment, installing the drain trap prevents outdoor air from being pulled into the drain pan and consequently forcing water out of the pan and into the unit.

To ensure the drain trap works properly, the trap height must account for the difference in static pressure between ambient conditions outside the unit and the internal negative pressure of the cooling coil compartment. For energy recovery units, an assumption of 3.0 in. wg differential will be sufficient. This would require a trap design as shown. If the internal static is believed to be higher, consult factory.

Refer to local codes to determine drainage requirements. If draining onto to roof, place a drip pad below drain to protect roof. If draining onto roof is not acceptable, a drain line must be attached to the trap. The drain line must be pitched away from the unit at least 1/8-in. per foot. On longer runs, an air break should be used to ensure proper drainage. Local codes may require drainage into a waste water system.

Drainage problems not only occur from improper drain trap design, but also from lack of maintenance of the cooling coil compartment. Algae can form in the drain pan and trap and cause reduced water flow, which can in turn result in backup into the system. Regular maintenance will prevent this from occurring. If the drains have a cleanout opening, be sure to close the opening after cleaning.

4 in.

2 in.

Page 13

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Electric Heater Application/Operation

Factory installed electric heaters can be provided for preheat and/or post-heat. An electric preheater warms the outdoor air prior to the energy recovery wheel to prevent frosting on the wheel. An electric post-heater warms the air leaving the energy recovery wheel to a user specified discharge temperature. Electric heaters are available in 208, 230, or 460 Vac (refer to heater nameplate for voltage).

Preheaters: Preheaters are standard as 2-stage, step control. Step control heaters are designed with

multiple stages made up of equal increments of heating capability. For example, a 10 kW heater with two stages will be composed of two 5-kW stages. Preheaters are single point wired at the factory. A temperature sensor (with field adjustable set point) is mounted in the outdoor airstream after the preheater to turn the preheater on. See Frost Control Application /Operation for typical set points. If the temperature falls below the set point and the wheel pressure drop sensor is triggered, the first stage of the preheater will turn on. If the first stage does not satisfy the set point, the second stage will also turn on.

Post-heaters: Post-heaters are standard as SCR control. Post-heaters are not single point wired (see

Electrical Connections). A temperature sensor (with field adjustable set point) is mounted in the outdoor airstream after the post-heater to turn the post-heater on. A SCR heater provides an infinitely modulating control of the heat to provide an accurate discharge temperature. A call for heat is required.

Electric Preheater

The pre-heater is single point wired to the ERCH control center. Access to the preheater control panel is through the supply filter door.

Cooling Coil

Post-Heater Control Panel

The post-heater is not single point wired to the ERCH control center. Separate power must be supplied to the post-heater disconnect (located in unit control center).

See ’Access Door Descriptions and Locations’ for access to post-heater control panel. For Model ERCH, the exhaust filters must be removed from the unit to access.

Electric

Post-Heater

Page 14

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Frost Control Application/Operation

Extremely cold outdoor air temperatures can cause moisture condensation and frosting on the energy recovery wheel. Frost control is an optional feature that will prevent/control wheel frosting. Three options are available:

1) Timed Exhaust frost control

2) Electric preheat frost control

3) Modulating wheel frost control

All of these options are provided with a thermostat (with probe) mounted in the outdoor air intake compartment and a pressure sensor to monitor pressure drop across the wheel. The typical temperature setting corresponds to the indoor air relative humidity as shown in the Frost Threshold Temperatures Table and represents when frost can occur. An increase in pressure drop would indicate that frost is occurring. Both the pressure sensor AND the outdoor air temperature sensor must trigger in order to initiate frost control. The two sensors together ensure that frost control is only initiated during a real frost condition. Field wiring of a light (or other alarm) between 6 & C in the control center will notify personnel when unit is in frost control mode (refer to Remote Panel Wiring schematics section for wiring details). The following explains the three options in more detail.

Timed exhaust frost control includes a timer in addition to the thermostat and wheel pressure sensor. When timed exhaust frost control is initiated, the timer will turn the supply blower on and off to allow the warm exhaust air to defrost the energy recovery wheel. Default factory settings are 5 minutes off and 30 minutes on. Use the following test procedure for troubleshooting.

Testing (refer to diagram at right)

• Jumperthewheelpressureswitchintheunitcontrolcenter.Setthe

Timer Scale for T1 and T2 to 1 minute. Set the Timer Settings for T1 and T2 to 1.0. Set the dip switch to the down position. (normal position)

• Turnthetemperaturesensorupashighaspossible.Thesupplyblower

should cycle on for one minute, then turn off for one minute.

• Aftertesting,settheTimer Scale as follows: T1 = 10 minutes, T2 = 1 hour

• SettheTimer Settings as follows: T1 = 0.5, T2 = 0.5. The timer is now set for 5 minutes off and 30 minutes on. Remember to remove the jumper.

Electric preheat frost control includes an electric heater (at outdoor air intake) and an airflow pressure switch (located at the preheater) in addition to the thermostat and pressure sensor on wheel. (Refer to Electric Heater Application/Operation for electric preheater location). When electric preheat frost control is initiated, the electric preheater will turn on and warm the air entering the energy wheel to avoid frosting. Use the following test procedure for troubleshooting.

Testing

• Turnthethermostatashighasitwillgoandjumperthewheelpressuresensor.Theheater

should turn on.

• Ifitdoesn’t,eitherputtheoutdoorairsidedoorsonortemporarilyjumpertheairflowpressure

switch in the preheater control center to avoid nuisance tripping of the pressure switch. Also check the airflow switch pressure tap located at the supply discharge blower to ensure the tubing is connected and the tap is not blocked. Remember to remove the jumpers.

Modulating wheel frost control includes a variable frequency drive in addition to the thermostat and pressure sensor. When modulating wheel frost control is initiated, the variable frequency drive will reduce the speed of the wheel. Reducing the speed of the energy wheel reduces its effectiveness, which keeps the exhaust air condition from reaching saturation, thus, eliminating condensation and frosting. If the outdoor air temperature is greater than the frost threshold temperature OR the pressure differential is less than the set point, the wheel will run at full speed. If the outdoor air temperature is less than the frost threshold temperature AND the pressure differential is greater than the set point, the wheel will run at reduced speed until the pressure differential falls below the set point. The temperature and pressure differential set points are set at the factory, but are fieldadjustable (refer to VFD section for more information). The variable frequency drive will be fully programmed at the factory.

Indoor RH @ 70°F Frost Threshold Temp

20% -10º F

30% -5º F

40% 0º F

Frost Threshold Temperatures

A1 B1 15

0.60.8

0.41.0

Timer Scale

0.20

T21 MIN

T11 MIN

0.60.8

0.41.0

0.20

16 18 A2

Timer

Dip Switch

Page 15

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Economizer Application/Operation

The energy recovery wheel operation can be altered to take advantage of economizer operation (free cooling). Two modes are available: 1) De-energizing the wheel or 2) Modulating the wheel. A field supplied call for cool (Y1) is required.

De-energizing the wheel is accomplished with a signal from a Temperature or Enthalpy sensor mounted in the air intake compartment. This Primary sensor will de-energize the energy wheel when the outdoor air temperature (factory default is 65ºF) or enthalpy (factory default is the ‘D’ setting) is below the field adjustable set point. An Override temperature sensor is also furnished in the outdoor air intake compartment to deactivate economizer mode. The Override (with field adjustable set point) is set at some temperature lower than the Primary sensor (factory default is 50ºF). Effectively, the two sensors create a deadband where the energy recovery wheel will not operate and free cooling from outside can be brought into the building unconditioned.

Testing

Temperature Sensor with Override

• TurnbothTemperatureandOverridethermostatsdownaslowastheygo.The

wheel should be rotating.

• TurntheTemperaturesensorupashighasitgoes,andkeeptheOverride

sensor as low as it will go. The wheel should stop rotating.

• Turnbothsensorsashighastheywillgo.Thewheelshouldstartrotating.

• SettheTemperaturesensoratdesiredpointforeconomizeroperationtobegin.

Set the Override sensor at desired point for economizer operation to end (factory default is 65ºF and 50ºF, respectively).

Enthalpy Sensor with Override

• Turnunitpoweroff.DisconnectC7400solidstateenthalpysensorfromterminal

So on the enthalpy controller. Also, disconnect the 620 ohm resistor from terminal Sr on the enthalpy controller. Turn unit power on. The LED on the enthalpy controller should light and the energy recovery wheel should not rotate.

• Turnunitpoweroff.Reconnect620ohmresistortoterminalSrontheenthalpy

controller. Turn unit power on. The LED on the enthalpy controller should not light and the energy recovery wheel should energize and rotate.

If the steps above provide the results described, the enthalpy economizer is

working properly.

• Turnunitpoweroff.ReconnectC7400solidstateenthalpysensor

to terminal So.

Temperature Sensor

with Override

Enthalpy Sensor

with Override

Modulating the Wheel

In applications in which an internal heat gain is present in the space, the rotational speed of the energy wheel may be modulated (via variable frequency drive) to avoid overheating the space during the

Enthalpy

Controller

winter. The speed of the energy wheel will be controlled in response to the discharge temperature set point.

Sequence of Operation:

The variable frequency drive is fully programmed at the factory (refer to VFD section

for more information). A “call for cool” must be field wired to the unit (terminals provided in unit - refer to wiring diagram in unit control center) to allow for initiation of economizer mode. When the space calls for cooling, factory supplied controls will drive the following wheel operations:

TOA > T

TOA < TRA and TOA > T

TOA < TRA and TOA < T

: Wheel runs at full speed (maximum energy recovery)

: Wheel is stopped (no energy recovery)

: Wheel will modulate to maintain discharge temperature

where (TOA) is the outdoor air temperature set point, (TRA) is the return air temperature set point, and (TSA) is the supply air discharge thermostat set point.

Page 16

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Variable Frequency Drives for Energy Recovery Wheel

Factory installed VFD for the energy recovery wheel are programmed at the factory per the settings shown below. Refer to the instruction manual that ships with the unit when making adjustments. A copy of the manual can be found online at www.drives.com. For technical support, contact Yaskawa direct at 1-800-927-5292.

Yaskawa GPD-305 Drive

Parameter Setting n01 Access Level 1 n30 Ref Upper Limit 100% or 66%* n32 Motor Rated FLA Motor FLA n33 Elect Thermal Overload 1 n36 Multi-Function input (terminal S2) 10 n40 Multi-Function output (MA,MB,MC) 4 n41 Analog Freq. Reference Gain 0 n42 Analog Freq. Reference Bias 99 n46 Carrier Frequency 2 n58 Frequency Detection Level 20 n01 Access Level 0

*36 inch wheel is 66% (40Hz). All other wheels are 100% (60Hz).

Page 17

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Wiring Diagram

Following is an example of a typical wiring diagram located in the unit control center. This wiring diagram includes a legend highlighting which accessories were provided with the unit. Factory wiring and field wiring are also indicated. This particular example includes 1) variable frequency drives on the blowers requiring a modulating input, 2) modulating energy recovery wheel with factory controls for economizer, 3) energy recovery wheel rotation sensor, 4) outdoor air and exhaust air dirty filter switches, 5) motorized outdoor air and exhaust air intake dampers, and 6) timed exhaust frost control. Many other factory installed and wired accessories are available.

MAIN POWER

TO UNIT

GROUND

CONDENSING FAN 2

CONDENSING FAN 1

COMPRESSOR 2

COMPRESSOR 1

ST1

13 14

ST2-NO

CC1-NO

CC2-NO

DS1

CF2

CF1

CC2

CC1

620 OHM RESISTOR OR

RETURN AIR SENSOR

OUTDOOR AIR

SENSOR

MIXED AIR

SENSOR

COM NC

DB1

CH1 CH2

PS1

NO C COM NO

TR1

SR+

+ SO+ T T1

TS6

FCS

2-10V

LPS HPS

ST1 O.L.

96 95

ST2 O.L.

96 95

TO MA AND MC

ON VFD-W

24 VAC

THERMOSTAT(S) TS1, TS6

TS1

TO FR AND FC

ON VFD-W

(LOCATED IN CONDENSING FAN)

CF1 O.L.

1P1

1P2

CF2 O.L.

2P22P1

TR1

R14

MULTI-VOLTAGE PRIMARY 24 SECONDARY

A2 A1

OA-SENSOR

SENSOR

A1T1A2

CC2

A1A1A2

ST1

ST2

CC1

CF1

CF2

ST1

O.L.

LEGEND

EXHAUST FAN

O.L.

ST2

VFD-W

COM

EXHAUST DAMPER

EXHAUST FAN

SUPPLY DAMPER

SUPPLY FAN

ENERGY WHEEL

ROTATION SENSOR

THERMOSTAT CONTROLLER(S)

FROST CONTROL

ECONOMIZER CONTROL

COMPRESSOR 1

COMPRESSOR 2

COMPRESSOR INTERLOCKS

CONDENSING FAN 1

CONDENSING FAN 2

R14

MOTOR

SUPPLY FAN

MOTOR

ENERGY WHEEL

MCT3MA

FCFR

SEE BELOW FOR TERMINAL CONNECTIONS

C1 COOLING STAGE 1 RELAY C2 COOLING STAGE 2 RELAY CC COMPRESSOR CONTACTOR

CF CONDENSING FAN CONTACTOR

CH COMPRESSOR SUMP HEATER

D DAMPER

DB POWER DISTRIBUTION BLOCK

DL DAMPER LIMIT SWITCH DS DISCONNECT SWITCH

EC ECONOMIZER CONTROLLER

FCS CONDENSOR FAN CYCLE SWITCH

FU FUSES FU5 CONTROL TRANSFORMER FUSES (NOT ON CLASS II) FZ1 FREEZE PROTECTION HG HOT GAS REHEAT VALVE HPS HIGH PRESSURE SWITCH (MANUAL RESET)

LPS LOW PRESSURE SWITCH

PS1 WHEEL FROST PRESSURE SWITCH

PS2 SUPPLY DIRTY FILTER PRESSURE SWITCH

PS3 EXHAUST DIRTY FILTER PRESSURE SWITCH

R1 ENERGY WHEEL RELAY/CONTACTOR

R2 OCCUPIED/UNOCCUPIED RELAY R3 EXHAUST BLOWER VFD RELAY R4 SUPPLY BLOWER VFD RELAY R5 MODULATING WHEEL FROST CONTROL RELAY R6 ECONOMIZER RELAY R7 COMPRESSOR INTERLOCK RELAY

R8 EVAP RELAY (INDIRECT) R9 EVAP RELAY (DIRECT) R10 UNIT RELAY R11 POST HEAT RELAY R12 DEHUMIDIFICATION RELAY R13 ROOM CALL FOR HEAT RELAY R14 ROTATION SENSOR RELAY

R15 ROTATION SENSOR RELAY

S1 FAN SWITCH S2 ROTATION SENSOR (LOCATED BY WHEEL)

S3 ROTATION SENSOR (LOCATED BY WHEEL) S4 CALL FOR HEAT SWITCH S5 OCC/UNOCC SWITCH - CLOSED=OCCUPIED/OPEN=UNOCCUPIED S6 CALL FOR COOL SWITCH (FIRST STAGE)

o o

S7 CALL FOR COOL SWITCH (SECOND STAGE) S8 CALL FOR DEHUMIDIFICATION SWITCH ST MOTOR STARTER

T1 FROST CONTROL TIMER

TYPICAL SETTINGS t1(OFF) = 5 MIN., t2(ON) = 30 MIN. T4 ECONOMIZER WHEEL JOG TIMER TYPICAL SETTINGS t1(OFF) = 3 HRS., t2(ON) = 10 SEC. T5 EVAP DELAY OFF TIMER

T6 COMPRESSOR MINIMUM OFF TIMER (TYP. 3 MIN.) T7 COMPRESSOR MINIMUM OFF TIMER (TYP. 3 MIN.)

TR TRANSFORMER

TS1 FROST CONTROL THERMOSTAT (JUMPER - HEAT)

CLOSES ON TEMP. DECREASE TYPICAL SETTING 5° F. TS2 ECONOMIZER LOW LIMIT THERMOSTAT (JUMPER - HEAT) OPENS ON TEMP. DECREASE TYP. SETTING 20° OFFSET OR 50°F. TS3 ECONOMIZER UPPER LIMIT THERMOSTAT (JUMPER - HEAT) CLOSES ON TEMP. DECREASE TYP. SETTING 65° F./2° DIFF. TS4 ROOM OVERRIDE SENSOR TS5 INLET AIR POST HEATER LOCKOUT THERMOSTAT (AFTER WHEEL) CLOSES ON TEMP. DECREASE TYPICAL SETTING 65° F. TS6 INLET AIR COMPRESSOR LOCKOUT THERMOSTAT (JUMPER-HEAT )

OPENS ON TEMP. DECREASE TYPICAL SETTING 60° F./2° DIFF.

FACTORY SUPPLIED AND WIRED

o FIELD WIRED

FIELD CONTROL WIRING RESISTANCE SHOULD NOT EXCEED 0.75 OHM. IF RESISTANCE EXCEEDS 0.75 OHM THEN CONSULT FACTORY. USE 14 GAUGE MINIMUM WIRE THICKNESS FOR CONTROL WIRING.

REPLACEMENT FUSES: MUST HAVE A MINIMUM I.R. RATING OF 5 KA

CAUTION:

UNIT SHALL BE GROUND IN ACCORDANCE WITH N.E.C. POWER MUST BE OFF WHILE SERVICING.

USER INTERFACE CONNECTIONS:

USER TO VERIFY THAT TR1 CAN HANDLE THE VA LOAD OF INDICATOR DEVICES.

DIRTY FILTER INDICATOR SHOWN AS 24V POWER FROM UNIT.

PS2 SUPPLY DIRTY FILTER SWITCH

PS3 EXHAUST DIRTY FILTER SWITCH

FROST CONTROL INDICATOR

NC NO

ROTATION INDICATOR

12 C

Page 18

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Rotation Sensor

The rotation sensor monitors energy recovery wheel rotation. If the wheel should stop rotating, the sensor will close a set of contacts in the unit control center. Field wiring of a light (or other alarm) between terminals R & 12 in the unit control center will notify maintenance personnel when a failure has occurred (refer to Remote Panel Wiring Schematics section for wiring details).

Dirty Filter Sensor

Dirty filter sensors monitor pressure drop across the outdoor air filters, exhaust air filters, or both. If the pressure drop across the filters exceeds the set point, the sensor will close a set of contacts in the unit control center. Field wiring of a light (or other alarm) to these contacts will notify maintenance personnel when filters need to be replaced.

The switch has not been set at the factory due to external system losses that will affect the switch. This switch will need minor field adjustments after the unit has been installed with all ductwork complete. The dirty filter switch is mounted in the exhaust inlet compartment next to the unit control center or in unit control center.

To adjust the switch, the unit must be running with all of the access doors in place, except for the compartment where the switch is located (exhaust intake compartment). The adjusting screw is located on the top of the switch. Open the filter compartment and place a sheet of plastic or cardboard over 50% of the filter media. Replace the filter compartment door. Check to see if there is power at the alert signal leads (refer to electrical diagram). Whether there is power or not, turn the adjustment screw on the dirty filter gauge (clockwise if you did not have power, counterclockwise if you did have power) until the power comes on or just before the power goes off. Open the filter compartment and remove the obstructing material. Replace the door and check to make sure that you do not have power at the alert signal leads. The unit is now ready for operation.

Positive pressure connection is toward the ‘back or bottom’ of the switch (senses air inlet side of filters)

Setscrew (on front of switch) must be manually adjusted after the system is in operation.

Negative pressure connection is toward the ‘front or top’ of the switch (senses blower side of filters)

DDC Temperature Control Package

Temperature control package allows for stand-alone operation of energy recovery units provided with supplemental cooling and heating. Controller can be ordered for discharge or room control. Room control would require a room thermostat (or other call for heat or cool) be wired to the controller. A remote panel option is also available to allow set points and other controller parameters to be adjusted from a remote location. For additional information, refer to the controls catalog and Installation, Operation and Maintenance Manual.

Page 19

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

CO2 Sensor

This accessory is often used to provide a modulating control signal to a variable frequency drive to raise and lower airflow in relationship to the CO2 levels in the space. This strategy is often referred to as Demand Control Ventilation and provides further energy savings to the system. Follow instructions supplied with sensor for installation and wiring details.

Service Outlet

120 Vac GFCI service outlet ships loose for field installation. Requires separate power source so power is available when unit main disconnect is turned off for servicing.

Vapor Tight Lights

Vapor tight lights provide light to each of the compartments in the energy recovery unit. The lights are wired to a junction box mounted on the outside of the unit. The switch to turn the lights on is located in the unit control center. The switch requires a separate power source to allow for power to the lights when the unit main disconnect is off for servicing.

Page 20

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Remote Control Panel and Wiring Schematics

The remote panel is available with a number of different alarm lights and switches to control the unit. The remote panel ships loose and requires mounting and wiring in the field.

The remote panel is available with the following options:

 • Uniton/offswitch  • Uniton/offlight  • 7-daytimeclock  • Hand/off/autoswitch  • Dirtyfilterlight  • Economizerlight  • Frostcontrollight  • Wheelrotationsensorlight

Refer to Electrical Connections section for Field Control Wiring recommendations.

7-Day Timer or On/Off Switch

7-Day Timer

For 7-Day Timer, use blue and black wires. Red wires should be capped off.

Hand/Off/Auto Switch

Hand/Off/Auto Switch allows the unit to “Off” - off “On” - Manual Operation “Auto” - Unit is controlled by BMS, RTU, etc.

S1 - Unit On/Off

Off

Auto

BMS

Terminal Block

Unit Control

Center

Terminal Block

Unit Control

Center

NOTE: RTU controllers are by others.

Page 21

OPTIONAL ACCESSORIES

Remote Panel Wiring Schematics

Indicator Lights powered by the ER Unit

Energy Recovery Unit with Packaged DX

Unit On/Off

Frost Control

Economizer Rotation Sensor

Dirty Filter Indicator (Power by Others)

PS2

NC NO

PS3

NC NO

PS2

Dirty Filter

PS3

Hot

Refer to Pressure Switch for voltage and load ratings.

Page 22

OPTIONAL ACCESSORIES

Remote Panel Wiring Schematics

Heating/Cooling Switches and Night Setback Switch/Timer

Unit On/Off

Econ/First Stage Cooling

Second Stage Cooling

Heat

Unit On/Off

Econ/First Stage Cooling

Second Stage Cooling

Heat

Energy Recovery Unit with Packaged DX

Terminal Block

in unit

Control Center

Terminal Block

Unit Control

Center

Night Setback Timer

Night Setback Switch

Page 23

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES

Sensors Mounted by Factory

Factory mounted temperature, pressure, and current sensors are available in the locations indicated on the unit diagram below. A list of available sensors is shown below. The specific sensors provided on a given unit are labeled in the unit control center on the terminal strip. Sensors are wired to the terminal strip to make it easy for the controls contractor to connect the Building Management System for monitoring purposes.

OUTSIDE

FROM

OUSTIDE

EXHAUST

BLOWER

OAF-P

FILTER

EAWEF-A

OAI

EW-P

ENERGY WHEEL

OAW-P

OAAW

COOL

COIL

RAI

ACC

HEAT COIL

RAF-P

FILTER

OAF-A

SUPPLY BLOWER

FROM INSIDE

TO INSIDE

OAD

Temperature Sensors - 1K Ohm RTD

Drawing Labels Terminal Strip Labels

OAI OA/Supply Inlet Temp OAAW OA After Wheel ACC After Cooling Coil Temp OAD Supply Discharge Temp EAW Exhaust After Wheel Temp RAI RA/Exhaust Inlet Temp

Pressure Sensors (analog or digital)

Drawing Labels Terminal Strip Labels

OAF-P OA/Supply Filter Pressure OAW-P Outdoor Air Wheel Pressure RAF-P RA/Exhaust Filter Pressure EW-P Exhaust Wheel Pressure

Amp - Current Sensors (analog or digital)

Drawing Labels Terminal Strip Labels

OAF-A Supply Fan Amps EF-A Exhaust Fan Amps

Page 24

START-UP CHECKLIST FOR UNIT

Energy Recovery Unit with Packaged DX

SAFETY DANGER!

Electric shock hazard. Can cause injury or death. Before

attempting to perform any service or maintenance,

turn the electrical power to unit to OFF at disconnect

switch(es). Unit may have multiple power supplies.

SAFETY CAUTION!

Do not operate energy recovery ventilator without the

filters and birdscreens installed. They prevent the entry of

foreign objects such as leaves, birds, etc.

Use caution when removing access panels or other unit

components, especially while standing on a ladder or

other potentially unsteady base. Access panels and unit

components can be heavy and serious injury may occur.

Do not run unit during construction phase. Damage to

internal components may result and void warranty.

SAFETY CAUTION!

CAUTION!

CAUTION! WARNINGS!

• Unitwasfactorytested.Allblowers,fans,andcompressorsareset-uptoruncorrectwhensupplied

power. If any one fan is running backwards or the compressor is making loud noises, immediately turn off the power. Switch two leads on the incoming power to the disconnect. This will ensure proper operation of the unit. Failure to comply may damage the compressors and void the warranty.

• Donotjumperanysafetydeviceswhenoperatingtheunit.Thismaydamagecomponentswithinorcause

serious injury or death.

• Donotoperatecompressorwhentheoutdoortemperatureisbelow40ºF.

• Donotshort-cyclethecompressor.Allow5minutesbetween“on”cyclestopreventcompressordamage.

• Priortostartinguptheunit,powermustbeenergizedfor24hourswithoutacallforcooltoallowthe

compressor crankcase heaters time to boil off any liquid refrigerant present in the compressor.

• DXsystemischargedwithrefrigerant.Start-upmustbeperformedbyEPACertifiedTechnician.

Every installation requires a comprehensive start-up to ensure proper operation of the unit. As part of that process, the following checklist must be completed and information recorded. Starting up the unit in accordance with this checklist will not only ensure proper operation, but will also provide valuable information to personnel performing future maintenance. Should an issue arise which requires factory assistance, this completed document will allow unit experts to provide quicker resolve. Qualified personnel should perform start-up to ensure safe and proper practices are followed.

Unit Model Number ___________________________ (e.g. ERCH-55)

Unit Serial Number ___________________________ (e.g. 04C99999 or 10111000)

Energy Wheel Date Code ___________________________ (e.g. 0450)

Compressor 1 Model Number ___________________________ (e.g. ZR36-XXXX)

Compressor 2 Model Number ___________________________ (e.g. ZR36-XXXX)

Start-Up Date ___________________________ (MM/DD/YYYY)

Start-Up Personnel Name ___________________________

Start-Up Company ___________________________

Phone Number ___________________________

Page 25

Energy Recovery Unit with Packaged DX

START-UP CHECKLIST FOR UNIT

Pre-Start Up Checklist - check boxes as items are completed

o Disconnect and lock-out all power switches o Remove any foreign objects that are located in the energy recovery unit. o Check all fasteners, set-screws, and locking collars on the fans, bearings, drives, motor bases and

accessories for tightness.

o Rotate the fan wheels and energy recovery wheels by hand and ensure no parts are rubbing. If rubbing

occurs, refer to Start-Up section for more information.

o Check the fan belt drives for proper alignment and tension (refer to Start-Up section for more

information).

o Filters can load up with dirt during building construction. Replace any dirty pleated filters and clean the

aluminum mesh filters in the intake hood (refer to Routine Maintenance section).

o Verify that non-motorized dampers open and close properly. o Check the tightness of all factory wiring connections. o Verify control wire gauge (refer to the Electrical Connections section). o Verify diameter seal settings on the energy recovery wheel (refer to Start-Up section for more

information).

o Verify proper drain trap installation (refer to Drain Trap section). o Check condensing fans for any damage or misalignment. Spin the blades and make sure they don’t

contact any parts and are free turning without any resistance.

o Look over the piping system. Inspect for oil at all tubing connections. Oil typically highlights a leak in

the system. If a leak is present, refer to the Maintenance section in this manual.

o Inspect all coils within the unit. Fins may get damaged in transit or during construction. Carefully

straighten fins with a fin comb.

o If there is an indirect gas-fired furnace in this unit, refer to the PVF IOM provided with this unit for __

Pre- Start-Up information.

o This unit contains a crankcase heater for each compressor which needs power supplied to it 24 hours

prior to start-up. If start-up is scheduled in 24 hours, unlock the disconnect power and energize unit.

Special Tools Required

 •VoltageMeter(withwireprobes) •Thermometer  •AmperageMeter •PressureGauges  •Inclinemanometerorequivalent •TemperatureGaugescapableofmeasuringpipetemperature  •Tachometer

Start-Up Checklist

The unit will be in operational mode during start-up. Use necessary precautions to avoid injury. All data must be collected while the unit is running. In order to measure volts & amps, the control center door must be open, and the unit energized using a crescent wrench to turn the disconnect handle.

Start-Up Procedure

• MakesurePre-Start-Upchecklistiscomplete.

• JumperRtoG,RtoY1,andRtoY2(ifapplicable)onthecontrolboard.

• Turnthedisconnecton.After3minutescompressorswillcomeon.Makesureallfansandcompressorsare

rotating the correct direction.

WARNING!

All motor(s) / compressor(s) have been checked for rotation. If blower rotation is incorrect, wiring must be

changed at the disconnect to ensure all motor(s) / compressors are corrected.

Operation of scroll compressor(s) in this unit are directional and will be damaged if run with the wrong direction.

• Allowtheunittorununtiltherefrigerantsystemstabilizes.Approximately1-2minutes.

• Takethefollowingmeasurementswhiletheunitisrunningtoensureproperoperation.

Page 26

Energy Recovery Unit with Packaged DX

START-UP CHECKLIST FOR UNIT

Line Voltage - check at unit disconnect L1-L2 ________ Volts L2-L3 ________ Volts L1-L3 _______ Volts Motor Amp Draw: Supply Motor Amps L1 ________ Amps L2 ________ Amps L3 ________ Amps Exhaust Motor Amps L1 ________ Amps L2 ________ Amps L3 ________ Amps

Fan RPM: Supply Fan RPM _____________ Exhaust Fan RPM _____________

Correct fan rotation direction: Supply Fan Yes / No Exhaust Fan Yes / No

Energy Wheel Motor: L1 ________ Amps L2 ________ Amps L3 ________ Amps

Compressor 1: L1 ________ Amps L2 ________ Amps L3 ________ Amps Crankcase Heater ________ Amps

Compressor 2: L1 ________ Amps L2 ________ Amps L3 ________ Amps Crankcase Heater ________ Amps

Condensing Fan 1: L1 ________ Amps L2 ________ Amps L3 ________ Amps Condensing Fan 2: L1 ________ Amps L2 ________ Amps L3 ________ Amps Condensing Fan 3: L1 ________ Amps L2 ________ Amps L3 ________ Amps

Outdoor Air Temperature ________ Deg F

Return Air Temperature ________ Deg F

Outdoor Air Relative Humidity ________ % RH

Return Air Relative Humidity ________ % RH

Superheat ________ Deg F Should be between 8º and 12ºF

Subcooling ________ Deg F Should be between 12º and 17ºF

Discharge Pressure PSIG Should be between 200 and 280 PSIG for R22 or 300 and 500 PSIG for R410a

Suction Line Pressure PSIG Should be between 60 and 80 PSIG for R22 or 100 and 135 PSIG for R410a

Liquid Line Temp ________ Deg F

Suction Line Temp ________ Deg F

Moisture Indicating Sight Glass Liquid Visible Yes / No Color of Center Dot Green / Yellow

Hot Gas Bypass Operational Yes / No

Page 27

Energy Recovery Unit with Packaged DX

OPTIONAL ACCESSORIES CHECKLIST

Refer to the respective sections in this Installation, Operation and Maintenance Manual for detailed information.

Refer to wiring diagram in unit control center to determine what electrical accessories were provided.

Provided with Unit? Frost Control Application / Operation section: Setting Factory Default

Yes No Frost Control set point 5ºF

Differential 2ºF Timer Refer to IOM

Yes No Frost Control Modulating Refer to IOM

Economizer Application / Operation section:

Yes No Economizer (temperature)

Set point 65ºF

Offset 20ºF

Differential 2ºF

Yes No Economizer (enthalpy)

Set point B

Yes No Economizer (modulating) Refer to IOM

Optional Accessories section: Operational

Yes No Wheel Rotation Sensor Yes No N/A

Yes No OA Dirty Filter Sensor Yes No N/A

Yes No EA Dirty Filter Sensor Yes No N/A

Yes No CO

Yes No Service Outlet Yes No N/A

Yes No Vapor Tight Lights Yes No N/A

Yes No Remote Control Panel Yes No N/A

Variable Frequency Drives section: Operational

Yes No Blower VFDs Yes No N/A

Yes No Wheel VFD Yes No N/A

Damper section: Operational

Yes No Outdoor Air Damper Yes No N/A

Yes No Exhaust Air Damper Yes No N/A

Yes No Night Setback Damper Yes No N/A

Sensor Yes No N/A

Yes No Indirect Gas Furnace (refer to the PVF IOM, Part #461006 for start-up information)

Page 28

Energy Recovery Unit with Packaged DX

Belt Span

Deflection =

Belt Span

Deflection =

Belt Span

WRONG WRONG

MOTOR

FAN

MOTOR

UNIT START-UP

Refer to Parts List section for component locations.

Fans

The ERCH models contain a forward curved supply fan and a forward curved exhaust fan. These forward curved fans should be checked for free rotation. If any binding occurs, check for concealed damage and foreign objects in the fan housing. Be sure to check the belt drives per the start-up recommendations in the following section.

SAFETY CAUTION!

When operating conditions of the fan are to be changed (speed, pressure, temperature, etc.), consult Greenheck to

determine if the unit can operate safely at the new conditions.

Fan Performance Modifications

Due to job specification revisions, it may be necessary to adjust or change the sheave or pulley to obtain the desired airflow at the time of installation. Start-up technician must check blower amperage to ensure that the amperage listed on the motor nameplate is not exceeded. Amperage to be tested with access doors closed and ductwork installed.

Forward

Curved

Fan

Fan Belt Drives

The fan belt drive components, when supplied by Greenheck, have been carefully selected for the unit’s specific operating condition. Caution: utilizing different components than those supplied could result in unsafe operating conditions which may cause personal injury or failure of the following components: 1) Fan Shaft, 2) Fan Wheel,

3) Bearings, 4) Belt, 5) Motor. Tighten all fasteners and set screws securely and realign drive pulleys after adjustment. Check pulleys and belts for proper alignment to avoid unnecessary belt wear, noise, vibration and power loss. Motor and drive shafts must be parallel and pulleys in line (see below).

Belt Drive Installation

1. Remove the protective coating from the end of the fan shaft and assure that it is free of nicks and burrs.

2. Check fan and motor shafts for parallel and angular alignment.

3. Slide sheaves on shafts. Do not drive sheaves on as this may result in bearing damage.

4. Align fan and motor sheaves with a straight-edge or string and tighten.

5. Place belts over sheaves. Do not pry or force belts, as this could result in damage to the cords in the belts.

6. With the fan off, adjust the belt tension by moving the motor base. (See belt tensioning procedures in the Routine Maintenance section of this manual). When in operation, the tight side of the belts should be in a straight line from sheave to sheave with a slight bow on the slack side.

WRONG WRONG

Proper alignment of motor and drive shaft.

WRONG CORRECT

Page 29

UNIT START-UP

Backward Inclined

Direction of Fan Wheel Rotation

Blower access is labeled on unit. Check for proper wheel rotation by momentarily energizing the fan. Rotation is determined by viewing the wheel from the drive side and should match the rotation decal affixed to the fan housing (see Rotation Direction figures). If the wheel is rotating the wrong way, direction can be reversed by interchanging any two of the three electrical leads.

noise, vibration, or overheating of bearings. Refer to the Troubleshooting section of this manual if a problem develops.

Fan RPM

Supply fan and exhaust fan will have an adjustable motor pulley (on 15 HP and below) preset at the factory to the customer specified RPM. Fan speed can be increased or decreased by adjusting the pitch diameter of the motor pulley. Multi-groove variable pitch pulleys must be adjusted an equal number of turns open or closed. Any increase in fan speed represents a substantial increase in load on the motor. Always check the motor amperage reading and compare it to the amperage rating shown on the motor nameplate when changing fan RPM. All access doors must be installed except the control center door. Do not operate

units with access doors open or without proper ductwork in place as the fan motors will overload.

Check for unusual

Energy Recovery Unit with Packaged DX

Airflow

Forward Curved

Vibration

Excessive vibration may be experienced during initial start-up. Left unchecked, excessive vibration can cause a multitude of problems, including structural and/or component failure. The most common sources of vibration are listed below.

1. Wheel Unbalance

2. Drive Pulley Misalignment

3. Incorrect Belt Tension

4. Bearing Misalignment

5. Mechanical Looseness

6. Faulty Belts

7. Drive Component Unbalance

8. Poor Inlet/Outlet Conditions

9. Foundation Stiffness

Many of these conditions can be discovered by careful observation. Refer to the Troubleshooting section of this manual for corrective actions. If observation cannot locate the source of vibration, a qualified technician using vibration analysis equipment should be consulted. If the problem is wheel unbalance, in-place balancing can be done.

Generally, fan vibration and noise is transmitted to other parts of the building by the ductwork. To eliminate this undesirable effect, the use of heavy canvas connectors is recommended.

Coils

Leak test thermal system to insure tight connections. Check for properly trapped condensate drain.

Page 30

Energy Recovery Unit with Packaged DX

UNIT START-UP

Inside layout of ERCH

Energy Recovery Wheel

The ERCH models contain a total energy recovery wheel. The wheels are inspected for proper mechanical operation at the factory. However, during shipping and handling, shifting can occur that may affect wheel operation. The wheel is accessible through the access door marked “Energy Wheel Cassette Access”. For the ERCH-20 and ERCH-45 models, the wheel cassette slides out. Due to the size and weight of the ERCH-55 and ERCH-90 wheels, they remain stationary and all maintenance is performed in place. There is room inside the unit to perform energy recovery wheel servicing.

Turn the energy recovery wheels by hand to verify free operation. The wheel should rotate smoothly and should not wobble.

Drive Belt

Inspect the drive belt. Make sure the belt rides smoothly through the pulley and over the wheel rim.

Air Seals

Check that the air seals located around the outside of the wheel and across the center (both sides of wheel) are secure and in good condition. Air seal clearance is determined by placing a sheet of paper, to act as a feeler gauge, against the wheel face. To access seals, enter unit for ERCH-55 and ERCH-90 or pull out the cassette for ERCH-20 and ERCH-45 following the instructions in Energy Recovery Wheel Maintenance section. To adjust the air seals, loosen all eight seal retaining screws. These screws are located on the bearing support that spans the length of the cassette through the wheel center. Tighten the screws so the air seals tug slightly on the sheet of paper.

Replace cassette into unit, plug in wheel drive, replace access door and apply power. Observe by opening door slightly (remove filters if necessary to view wheel) that the wheel rotates freely at about 50-60 rpm.

Adjustable

Air Seals

Drive Belt

Drive Pulley

Bearing Support

Label showing

cassette serial #

and date code

Page 31

REFRIGERATION SYSTEM

HIGH PRESSURE

SWITCH

410 / MANUAL RESET

R22

600 / MANUAL RESET

R410a

CONDENSING FAN

HEAD PRESSURE

FAN CONTROL

275/210 PSI

R22

425/330 PSI

R410a

CONDENSER COIL

Energy Recovery Unit with Packaged DX

SIGHT GLASS

LIQUID LINE FILTER DRIER

CHARGING PORT

LOW PRESSURE SWITCH 25/80 PSI - R22 50/90 PSI - R410a

COMPRESSOR(S)

SOLENOID VALVE

SCHRAEDER VALVE

MANUAL VALVE

EQUALIZER LINE

CHARGING

PORT

TXV

EVAPORATOR COIL

HGBP

Factory Installed Refrigeration System Components

Thermostatic Expansion Valve (TXV) - each unit is equipped with a thermal expansion valve. The valve controls the flow of liquid refrigerant entering the evaporator coil by maintaining a constant, factory set superheat of 10ºF. The valve is located on the side of the evaporator coil and can be accessed through the exhaust airstream, through the coil panel access door.

Refrigerant Distributor - attached to the TXV is a refrigerant distributor. The refrigerant distributor

evenly distributes the refrigerant to each circuit of the evaporator coil to provide optimum performance.

Evaporator Coil - each unit contains a single circuit evaporator coil. The coil is located in the outdoor

airstream, directly after the energy wheel. In the DX system, the liquid refrigerant is expanded in the TXV, and then flows through the evaporator coil. The refrigerant enters the coil as low temp liquid/gas where it eventually boils into a low temp, low pressure gas prior to going to the compressor. To ensure proper operation, the coil surface must be cleaned so that air movement over the coil provides the necessary heat transfer.

Low Limit Pressure Switch - the unit includes a low limit pressure switch (located in the compressor

compartment). The switch is installed in the suction line and shuts off the DX system when the suction pressure drops to 25 psi for R22 or 50 psi for R410a. The switch has a built in auto-reset, which will close the circuit and allow the system to run when the pressure increases back to 80 psi for R22 or 90 psi for R410a.

THERMAL EXPANSION VALVE (TXV)

HOT GAS BYPASS VALVE (HGPB)

Compressors - each unit includes 1 or 2 high efficiency scroll type compressors depending on needed

capacity. Scroll type compressors are essentially maintenance free since they are a self-contained, selfcooling design. The scroll compresses the refrigerant in the gaseous state to a high temperature, high pressure gas.

Compressor protective devices:

Thermal Overload - each compressor is equipped with an auto reset thermal overload

High Temp Protection - internal devices within the compressor protect it against excessively

high discharge gas temperatures (only on compressors above 6 hp)

Crankcase Heater - Liquid refrigerant is incompressible. Therefore, a crankcase heater

is installed around each compressor in the unit to boil any liquid refrigerant that may be absorbed into the oil during idle periods. System power energizes the heater; it is recommended the heater is allowed to run 24 hours prior to compressors being started.

Page 32

REFRIGERATION SYSTEM

Factory Installed Refrigeration System Components

Condensing Coil - each unit contains a condensing coil mounted on the exterior of the unit. High

temperature, high pressure gas from the compressor enters the coil and is eventually cooled into a high temperature, high pressure liquid. The condensing fans move air over the coil which pulls the heat out of the refrigerant. To ensure proper operation, the coil must be cleaned so that air movement over the coil provides the necessary heat transfer.

Condenser Fans - depending on capacity, the unit is equipped with either 2 or 3 direct-drive

condensing fans. The fans provide the necessary airflow to cool the refrigerant in the condensing coil. Depending on head pressure, one fan may not be running, which is normal operation for this unit and does not highlight a problem. The motors are equipped with sling protection to guard against water penetration, and are thermally protected. The thermal overloads shut down the condensing fans.

High Limit Pressure Switch - to safely shutdown the DX system, in case of an increase in refrigerant

pressure, a high limit pressure switch is included (located in compressor compartment). The switch is located in the compressor compartment. It trips when refrigerant pressure increase to 410 psi for the R22 (600 psi for R410a) in the liquid line, and can only be manually reset when the pressure drops below 290 psi. Typically if the high limit switch trips, a failure in the system has occurred and more investigation is needed to determine the underlying problem.

Head Pressure Cycle Switch - to maintain proper refrigerant pressures, a Fan-Cycle switch that

operates on head pressure is installed in the liquid line. When liquid line refrigerant pressure increases to 275 psi for R22 (425 psi for R410a), the switch closes and turns on an additional condensing fan to aid in cooling the refrigerant. After turning on, the fan will run until liquid line pressure drops down to 210 psi for R22 (330 psi for R410a) where it cycles off. The switch is located in the compressor compartment.

Energy Recovery Unit with Packaged DX

Liquid Line Filter Drier - the liquid line filter drier prevents moisture and foreign matter from entering

the thermal expansion valve. It is mounted in the compressor compartment.

Moisture Indicating Sight Glass - moisture in a DX system can cause great harm and break down the

refrigerant. Located in the compressor compartment is a moisture indicating sight glass. During normal operating conditions, the sight glass should typically be liquid. Some gas is acceptable, but excessive bubbles may indicate improper charge or a leak in the system. A green dot means moisture is below a safe operation level in the refrigerant, while a yellow dot indicates moisture has been introduced into the system and needs to be addressed.

Hot Gas Bypass Valve - on units equipped with hot bypass, hot gas from the compressor is injected

into the liquid line of the evaporator coil after the TXV. This process starts to occur when suction gas temperatures drop below 28ºF, which is 32º–34ºF coil surface temperature. Hot gas helps prevent the evaporator coil from freezing up and the compressor from cycling. The valve is factory set, but can be adjusted to exact specifications once installed in the field.

Valve Adjustment - to adjust the valve, connect a pressure gauge to the suction line and

block the entering air to the evaporator coil. The Valve should begin to open when the suction pressure drops to approximately 58 PSIG for R22 and 115 PSIG for R410a (the valve will feel warm to the touch). Adjustments are made by first removing the cap on the valve and then turning the adjusting stem clockwise to increase the setting pressure and counterclockwise to decrease the setting pressure. Allow several minutes between adjustments for system to stabilize. When adjustment is complete, replace the cap on the valve.

Access Ports - For easy measurement and charging access, several ports are provided throughout the

system. These can be used to measure system pressures, and also charge or evacuate the system. Most ports are located in the compressor compartment for easy access.

Page 33

ROUTINE MAINTENANCE

Energy Recovery Unit with Packaged DX

SAFETY DANGER!

Electric shock hazard. Can cause injury or death. Before

attempting to perform any service or maintenance,

turn the electrical power to unit to OFF at disconnect

switch(es). Unit may have multiple power supplies.

This unit requires minimal maintenance to operate properly. To ensure proper operation and longevity, the following items should be completed. The items in this list assume a relatively clean air environment, and may require attention more frequently in a dirty or dusty area. If this unit contains an Indirect Gas Heater, refer to the Installation, Operation and Maintenance Manual provided with the unit for maintenance purposes. A Certified Technician should complete all refrigerant systems checks.

Use caution when removing access panels or other unit

components, especially while standing on a ladder or

other potentially unsteady base. Access panels and unit

components can be heavy and serious injury may occur.

SAFETY CAUTION!

Monthly

External Filter Check for cleanliness – clean if required

Internal Filter Check for cleanliness – replace if required

Condensate Drain Inspect and clean – refill with water

Semi-Annually

Fan Belts Check for wear, tension, alignment

Energy Recovery Wheel Check for cleanliness – clean if required Check for belt wear Check pulley, bearings, and motor

Annually

It is recommended that the annual inspection and maintenance occur at the start of the cooling season. After completing the checklist, follow the unit start-up checklist provided in the manual to ensure the refrigeration system operates in the intended matter.

Lubrication Apply lubrication where required

Dampers Check for unobstructed operation

Motors Check for cleanliness

Fan Belts Check for wear, tension, alignment

Motors Check for cleanliness

Blower Wheel & Fasteners Check for cleanliness Check all fasteners for tightness Check for fatigue, corrosion, wear

Bearings Check for cleanliness Check set screws for tightness

Energy Recovery Wheel Check for cleanliness – clean if required Check belt for wear Check pulley, bearings, and motor

Door Seal Check if intact and pliable

Evaporator Coil Maintenance Check for cleanliness – clean if required

Condenser Coil Maintenance Check for cleanliness – clean if required

Condensate Drain Inspect and clean – refill with water

Condensing Fan Blades and Motor Check for cleanliness Check all fasteners for tightness Check for fatigue, corrosion, and wear

Wiring Connections Check all connections for tightness

Page 34

Energy Recovery Unit with Packaged DX

ROUTINE MAINTENANCE

Lubrication

Check all moving components for proper lubrication. Apply lubrication where required. Any components showing excessive wear should be replaced to maintain the integrity of the unit and ensure proper operation.

Dampers

Check all dampers to ensure they open and close properly and without binding. Backdraft dampers can be checked by hand to determine if blades open and close freely. Apply power to motorized dampers to ensure the actuator opens and closes the damper as designed.

Fan Belts

Belts must be checked on a regular basis for wear, tension, alignment, and dirt accumulation. Premature or frequent belt failures can be caused by improper belt tension (either too loose or too tight) or misaligned sheaves. Abnormally high belt tension or drive misalignment will cause excessive bearing loads and may result in failure of the fan and/or motor bearings. Conversely, loose belts will cause squealing on start-up, excessive belt flutter, slippage, and overheated sheaves. Both loose and tight belts can cause fan vibration.

When replacing belts on multiple groove drives, all belts should be changed to provide uniform drive loading. Do not pry belts on or off the sheave. Loosen belt tension until belts can be removed by simply lifting the belts off the sheaves. After replacing belts, insure that slack in each belt is on the same side of the drive. Belt dressing should never be used.

Do not install new belts on worn sheaves. If the sheaves have grooves worn in them, they must be replaced before new belts are installed.

Deflection =

Belt Span

Proper fan belt settings

Belt Span

The proper belt setting is the lowest tension at which the belts will not slip under peak load operation. For initial tensioning, set the belt deflection at 1/64-inch for each inch of belt span (measured half-way between sheave centers). For example, if the belt span is 64 inches, the belt deflection should be 1 inch (using moderate thumb pressure at mid-point of the drive). Check belt tension two times during the first 24 hours of operation and periodically thereafter.

Fan Motors

Motor maintenance is generally limited to cleaning and lubrication. Cleaning should be limited to exterior surfaces only. Removing dust and grease buildup on the motor housing assists proper motor cooling. Never wash-down motor with high pressure spray. Greasing of motors is only intended when fittings are provided. Many fractional motors are permanently lubricated for life and require no further lubrication.

Fan Wheel & Fasteners

Wheels require very little attention when moving clean air. Occasionally oil and dust may accumulate on the wheel causing imbalance. When this occurs the wheel and housing should be cleaned to assure smooth and safe operation. Inspect fan impeller and housing for fatigue, corrosion or wear.

Routinely check all fasteners, set screws and locking collars on the fan, bearings, drive, motor base and accessories for tightness. A proper maintenance program will help preserve the performance and reliability designed into the fan.

Page 35

ROUTINE MAINTENANCE

Energy Recovery Unit with Packaged DX

Internal Filter Maintenance

The ERCH units will typically be provided with 2-inch, pleated filters in the outdoor air and exhaust airstream. These filters should be checked per a routine maintenance schedule and replaced as necessary to ensure proper airflow through the unit. See table at right for pleated filter size and quantity for each

Model

ERCH-20 20 in. x 20 in. 2 2

ERCH-45 20 in. x 25 in. 3 3

ERCH-55 16 in. x 20 in. 6 6

ERCH-90 20 in. x 20 in. 8 8

Filter Size and Quantities

Internal

Filter Size

Quantity

Supply

Quantity

Exhaust

unit. Replacement filters shall be of same performance and quality as factory installed filters. Filter type must be pleated design with integral metal grid. Two acceptable filter replacements are Aerostat Series 400 or Farr 30/30®.

Outdoor Air Filters: Access to the outdoor air filters is through the door labeled as “Filter Access” on the outdoor air side of the unit.

Exhaust Air Filters: Access to the exhaust air filters is through the door labeled as “Filter Access” on the exhaust air side of the unit.

Refer to Access Door Descriptions section for additional information on filter locations.

External Filter Maintenance

Aluminum mesh, 2-inch deep filters are located in the supply weatherhood (if the weatherhood option was purchased). Filters should be checked and cleaned on a regular basis for best efficiency. The frequency of cleaning depends upon the cleanliness of the incoming air. These filters should be cleaned prior to start-up.

To access these filters, remove bottom bolt in the access door on the side of the weatherhood. Slide the access door up and then pull bottom out to remove door. Then, slide the filters out (see figure at right).

Clean filters by rinsing with a mild detergent in warm water.

Outdoor air intake hood

mesh filter access

Page 36

Energy Recovery Unit with Packaged DX

ROUTINE MAINTENANCE

Coil Maintenance

**WARNING**

REFER TO SAFETY WARNING ON COVER

DO NOT OPERATE ENERGY RECOVERY VENTILATOR WITHOUT THE FILTERS AND BIRDSCREENS INSTALLED.

THEY PREVENT THE ENTRY OF FOREIGN OBJECTS SUCH AS LEAVES, BIRDS, ETC.

DO NOT REMOVE ACCESS PANELS OR OTHER UNIT COMPONENTS WHILE STANDING ON A LADDER OR OTHER

UNSTEADY BASE. ACCESS PANELS AND UNIT COMPONENTS ARE HEAVY AND SERIOUS INJURY MAY OCCUR.

Filters

Filters upstream of the coil should be checked regularly. If the filters are dirty, they should be cleaned or replaced. It is important that the coils stay clean to maintain desired airflow. See Filter Maintenance section for additional information.

Coil Maintenance

1. Coils must be cleaned to obtain maximum performance. Check once a year under normal operating conditions and if dirty, brush or vacuum clean. Soiled fins reduce the capacity of the coil, demand more energy from the fan, and create an environment for odor and bacteria to grow and spread through the conditioned zone. High pressure water (700 psi or less) may be used to clean coils with fin thickness over

0.0095 inches thick. TEST THE SPRAY PRESSURE over a small corner of the coil to determine if the fins will withstand the spray pressure.

For coils with fragile fins or high fin density, foaming chemical sprays and washes are available. Many coil

cleaners contain harsh chemicals, so they must be used with caution by qualified personnel only. Care must be taken not to damage the coils, including the fins, while cleaning.

CAUTION: Fin edges are sharp.

**WARNING**

BIOLOGICAL HAZARD. MAY CAUSE DISEASE. CLEANING SHOULD BE PERFORMED BY QUALIFIED PERSONNEL.

2. Drain pans in any air conditioning unit will have some moisture in them, therefore, algae and other organisms will grow due to airborne spores and bacteria. Periodic cleaning is necessary to prevent this buildup from plugging the drain and causing the drain pan to overflow. Inspect twice a year to avoid the possibility of overflow. Also, drain pans should be kept clean to prevent the spread of disease. Cleaning should be performed by qualified personnel.

Page 37

ROUTINE MAINTENANCE

Energy Recovery Wheel Maintenance

Annual inspection of the energy recovery wheel is recommended. Units ventilating smoking lounges and other non-clean air spaces should have energy recovery wheel inspections more often based upon need. Inspections for smoke ventilation applications are recommended bimonthly to quarterly until a regular schedule can be established.

ACCESSING ENERGY RECOVERY WHEEL

The ERCH units have one energy recovery wheel. Open the outdoor air filter door to access the wheel. For the ERCH-20 and ERCH-45 models, the wheel cassette slides out. Due to the size and weight of the ERCH-55 and ERCH-90 wheels, they remain stationary and all maintenance is performed in place. There is room inside the unit to perform energy recovery wheel servicing. Filters must be removed to access stationary wheels.

Energy Recovery Unit with Packaged DX

**WARNING: Disconnect power to the unit before performing

any type of service.

REMOVING THE ENERGY RECOVERY WHEEL SEGMENTS

Models ERCH-20, 45, 55 & 90

Steel retainers are located on the inside of the wheel rim (see diagram at right). Push the retainer toward center of wheel, then lift up and away to release segments (see below).

Catch Segment Retainer

Lift away from segment

Push toward center

Access to wheel through

outdoor air filter door

Bracket Segment Retainer

Inside of wheel rim

Spoke

Center of Wheel

Wheel segment removed

IMPORTANT! PLACE RETAINERS BACK IN THE ORIGINAL

POSITION BEFORE ROTATING THE ENERGY RECOVERY WHEEL. OTHERWISE DAMAGE TO RETAINER WILL OCCUR.

Page 38

Energy Recovery Unit with Packaged DX

ROUTINE MAINTENANCE

CLEANING THE ENERGY RECOVERY WHEEL

If the wheel appears excessively dirty, it should be cleaned to ensure maximum operating efficiency. Only excessive buildup of foreign material needs to be removed. DISCOLORATION AND STAINING OF ENERGY

RECOVERY WHEEL DOES NOT AFFECT ITS PERFORMANCE.

Thoroughly spray wheel matrix with household cleaner such as Fantastic® or equivalent. Gently rinse with warm water and using a soft brush remove any heavier accumulation. A detergent/water solution can also be used. Avoid aggressive organic solvents, such as acetone. The energy recovery wheel segments can be soaked in the above solution overnight for stubborn dirt or accumulation.

After cleaning is complete, shake the excess water from the wheel or segments. Dry wheel or segments before placing them back into the cassette. Place wheel or segments back into cassette by reversing removal procedures.

** DO NOT CLEAN ENERGY RECOVERY WHEEL SEGMENTS WITH WATER IN EXCESS OF 140ºF. ** DO NOT DRY ENERGY RECOVERY WHEEL SEGMENTS IN AIR IN EXCESS OF 140ºF. ** THE USE OF A PRESSURE WASHER TO CLEAN SEGMENTS IS NOT RECOMMENDED. DAMAGE COULD

RESULT.

Energy Recovery Wheel Belt

Inspect belts each time filters are replaced. Belts that look chewed up or are leaving belt dust near the motor pulley may indicate a problem with the wheel. Be sure to inspect wheel for smooth and unrestricted rotation. If a belt requires replacement, contact the local Greenheck representative. Instructions for replacement will ship with the new belt.

Energy Recovery Wheel Bearings

In the unlikely event that a wheel bearing fails, access is available through the outdoor air filter door and through a removable plate in the divider in the unit (accessed through the exhaust air filter door). Contact the local Greenheck representative for detailed instructions on how to replace the bearing.

Wheel Belt & Pulley

Wheel Bearing

Page 39

PARTS LIST

Energy Recovery Unit with Packaged DX

Model ERCH

(shown with standard integral condensing section and optional electric heater)

1. Supply blower

- Forward curved fan

- Adjustable motor mount for belt tensioning

- Adjustable sheaves for speed control

2. Vibrations isolators (quantity 4 per blower)

- Neoprene

3. Energy recovery wheel cassette

4. Removable energy recovery wheel segments

5. Optional supply weatherhood with 2 in. aluminum mesh filter

6. Optional exhaust weatherhood with bird screen

7. Optional supply and exhaust air filter racks for 2 in. pleated, 30% efficient filters

8. Electrical control box (standard features)

- Single point power

- Disconnect interlocked with access door

- Motor starters for the supply blower, exhaust blower and energy wheel motors.

- 24 Vac, control circuit with terminal strip

9. Coil section houses supply air tempering options

- Packaged DX for cooling

- Electric or hot water heat

- Indirect gas heat

10. Exhaust blower

11. Compressor(s)

12. Condensing fans

13. Condensing coil

Page 40

Energy Recovery Unit with Packaged DX

SEQUENCE OF OPERATION

Basic Unit

The ERCH units are pre-wired such that when a call for outside air is made (via field supplied 24 Vac control signal wired to unit control center), the supply fan, exhaust fan and energy wheel are energized and optional motorized dampers open. The ERCH units can be supplied with or without heating coils. Controls can be supplied by Greenheck or by the controls contractor. If supplied by the controls contractor, they would provide, mount, and wire any temperature controllers and temperature or relative humidity sensors required for the unit to discharge air at the desired conditions. However, temperature, pressure, and current sensors can be provided by Greenheck for purposes of monitoring via the Building Management System (see Optional Accessories section).

Summer Operation:

Outdoor air is preconditioned (temperature and moisture levels are decreased) by the transfer of energy from the cooler, drier exhaust air via the energy recovery wheel. Units supplied with cooling coils can further cool the air coming off the wheel and strip out moisture to levels at or below room design. A heating coil downstream of the cooling coil can reheat the air to a more comfortable discharge temperature to the space.

Standard DX Sequence of Operation:

Unit without economizer

Ambient temperatures above 55ºF

 • Firstcallforcool,theunitwillturnonthefirstcompressor.  • Onthesecondcallforcool,theunitwillturnonthesecondcompressorifavailable.

(10 or larger tonnage system).

Unit without economizer

Ambient temperatures below 55ºF

 • DXsystemlockedoutandwillnotoperate.

Unit with economizer

With economizer conditions available and ambient temperature above 55ºF

 • Firstcallforcool-theunitwillcheckifitcanuseeconomizerair.Ifitcan,thewheelwillshutoffor

modulate and the cooling coil will be de-energized.

 • Secondcallforcool-theunitwillturnonacompressortoprovidethespacewithfurthercooling.

With economizer conditions available and ambient temperature below 55ºF

 • Firstcallforcool-theunitwillengageeconomizerallowingfreecoolingdowntominimumsetpoint, 

factory set at 50ºF.

 • Secondcallforcool-theDXsystemislockedout,notallowingcompressorstorunbelow55ºF.First 

stage of cooling will still operate unless ambient temperature drops below economizer set point.

Without economizer conditions available and ambient temperature above 55ºF

 • Firstcallforcool-theunitwillturnoncompressorone.  • Secondcallforcool-theunitwillturnonthesecondcompressorifavailable.

(10 or larger tonnage system).

Economizer Operation: See Economizer Application/Operation section.

Winter Operation:

Outdoor air is preconditioned (temperature and moisture levels are increased) by the transfer of energy from the warmer, more humid exhaust air via the energy recovery wheel. Units supplied with heating coils can further heat the air coming off the wheel to levels at or above room design.

Frost Control Operation: See Frost Control Application/Operation section.

Page 41

Energy Recovery Unit with Packaged DX

SEQUENCE OF OPERATION

Other Accessories:

Rotation Sensor See Optional Accessories section

Dirty Filter Sensor See Optional Accessories section

CO2 Sensor See Optional Accessories section

Night Setback On a call for night setback (unoccupied mode), the outdoor air damper will

close and the energy wheel and exhaust fan will be de-energized. The night setback dampers will open and the supply fan will remain on, providing 100% recirculation. Units supplied with heating and cooling coils will temper air as required by the controls to maintain desired conditions in the space.

DX Safety and General Control Sequence

To prevent damage to the system, there is a safety loop incorporated into the controls. This loop includes a check to make sure the supply fan starter is pulled in, ambient temperature is above 55ºF, and the low- and high-pressure switches are not tripped out. After this loop is verified, a relay then pulls in to start the anti-cycle timer. (Typical setting is 3 minutes). Once the timer has counted down, only then can the compressor contact pull in. Once the compressor contact pulls in, the first stage of condensing fans turns on. If pressure in the condensing coil increases to a point at which more heat needs to be removed from the system, the fan cycle switch will close and the second stage of condensing fans turns on.

Page 42

Energy Recovery Unit with Packaged DX

Troubleshooting – Airflow

Test and Balance Report

The Test and Balance Report (TAB) is utilized to determine whether the appropriate amount of outdoor air and exhaust air is being supplied and removed from a building, respectively. There are no set rules on what information must be included in a TAB report. As such, if a TAB report indicates that the airflow on a unit is low, prior to contacting the factory, please determine the following information:

Unit #1 Unit #2 Unit #3 Unit #4

Model Number

Serial Number

Name Plate Information

Voltage

Hertz

Phase

Outdoor Air Fan Amps

Exhaust Fan Amps

Outdoor Air Fan Horsepower

Exhaust Fan Horsepower

Design Airflow

Outdoor Air

Exhaust

Measured Airflow

Outdoor Air

Exhaust

Measured Data

Blower Rotation

Outdoor Air Fan RPM

Exhaust Fan RPM

Outdoor Air Fan Amp Draw

Exhaust Fan Amp Draw

Pressure Drop Across Energy Recovery Wheel

Outdoor Air Side

Exhaust Side

Airflow problems can often be tied back to improper ductwork installation. Be sure to install ductwork in accordance with SMACNA and AMCA guidelines.

Page 43

Energy Recovery Unit with Packaged DX

Troubleshooting – General Unit

Symptom Possible Cause Corrective Action

Blown fuse or open circuit breaker.

Defective motor or capacitor. Replace.

Replace fuse or reset circuit breaker and check amps.

Blower fails to

operate

Motor starters

“chatter” or

do not pull in

Motor over amps

Motor starter overloaded. Reset starter and check amps.

Electrical.

Drive.

Control power (24 Vac) wiring run is too long (resistance should not exceed 0.75 ohms).

Incoming supply power is less than anticipated. Voltage supplied to starter coil must be within +10% / -15% of nominal voltage stated on the coil.

CFM too high. Check cfm and adjust drives if needed.

Static pressures are higher or lower than design.

Blower rotation is incorrect. Check rotation and reverse if necessary.

Motor voltage incorrect.

Motor horsepower too low.

Shorted windings in motor. Replace motor.

Check for On/Off switches. Check for correct supply voltage.

Check for broken or loose belts. Tighten loose pulleys.

Shorten wiring run to mechanical room or install a relay which will turn unit on/off (C/F for relay information). Increase wire gauge size so that resistance is .075 ohms or less.

Need to increase supply power or use a special control transformer which is sized for the actual supply power.

If higher, ductwork should be improved. If lower, fan rpm should be lower.

Check motor nameplate versus supplied voltage.

See specifications and catalog for fan curves to determine if horsepower is sufficient.

Low airflow (cfm)

High airflow (cfm)

Unit damper not fully open. Adjust damper linkage or replace damper motor.

System static pressure too high.

Blower speed too low.

Fan wheels are operating backwards.

Dirty filter or energy wheel.

Leaks in ductwork. Repair.

Elbows or other obstructions may be obstructing fan outlet.

Belt slippage. Adjust belt tension.

Blower fan speed too high.

Filter(s) not in place. Install filters.

Insufficient static pressure (Ps) (airflow resistance).

Improve ductwork to eliminate losses using good duct practices.

Check for correct drives and rpm with catalog data.

For 3-phase, see Direction of Fan Wheel Rotation under Unit Start-Up section.

Follow cleaning procedures in Routine Maintenance section.

Correct or improve ductwork.

Check for correct fan rpm. Decrease fan speed if necessary.

Induce Ps into system ductwork. Make sure grilles and access doors are installed. Decrease fan speed if necessary.

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Page 44

Energy Recovery Unit with Packaged DX

Troubleshooting – General Unit

Symptom Possible Cause Corrective Action

One or both

blowers turn off

intermittently and

back on after

about 2 minutes

Exhaust Only frost control sensors are tripping.

Adjust frost temperature sensor set point as needed.

Energy wheel does

NOT turn

Energy wheel runs

intermittently

Air seals are too tight.

“Economizer” sensors are operating.

No power to wheel motor.

Wheel drive belt.

VFD overload. (OL1 on readout)

Wheel motor overloads are tripping, due to rubbing between wheel and air seals.

Fan wheel rubbing on inlet.

Bearings.

Wheel out of balance. Replace or rebalance.

Loose wheel on shaft. Tighten wheel setscrew.

Loose motor or blower sheave. Tighten sheave setscrew.

See Energy Recovery Wheel under Unit Start-Up section.

Adjust temperature or enthalpy set points as needed.

Make sure wheel drive is plugged in. Verify power is available.

Check for loose or broken belts. Replace belts (consult factory).

Refer to VFD section. Compare motor amp rating to setting in VFD. Adjust accordingly.

Recheck air seals, make sure they are not too tight. See Energy Recovery Wheel under Unit Start-Up Section.

Adjust wheel and/or inlet cone. Tighten wheel hub or bearing collars on shaft.

Replace defective bearings (s). Lubricate bearings. Tighten collars and fasteners.

Belts too loose. Adjust belt tension after 24 hours of operation.

Excessive noise

or vibration

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Belts too tight.

Worn belt. Replace.

Motor base or blower loose. Tighten mounting bolts.

Buildup of material on wheel. Clean wheel and housing.

Bearing and drive misaligned. Realign.

Noise being transmitted by duct.

Loosen to maintain a 3/8 inch deflection per foot of span between sheaves.

Make sure ductwork is supported properly. Make sure ductwork metal thickness is sized for proper stiffness. Check duct size at discharge to ensure that air velocities are not too high.

Page 45

Energy Recovery Unit with Packaged DX

Troubleshooting – General Refrigeration Circuit

IMPORTANT TROUBLESHOOTING

NOTE!

Before any components are changed on the

refrigeration system, the cause of the failure must be

identified. Further problems will exist unless the true

cause or problem is identified and corrected.

NOTE: Unit is equipped with a phase loss/phase reversal control. If system does not start, check phase of electrical supply.

Do not release refrigerant to the atmosphere! If

required service procedures include the adding or

removing of refrigerant, the service technician must

comply with all federal, state and local laws. The

procedures discussed in this manual should only be

performed by a qualified HVAC Technician.

IMPORTANT!

Symptom Possible Cause Corrective Action

Open disconnect switch or circuit breaker. Close switch and / or breaker.

Check voltage to contactor coil, transformer, slave relay, system. Replace parts as necessary.

Check for reason and repair. Replace fuse after correcting problem.

Check line voltage. If more than 10% from compressor marking, correcting is necessary.

Motor thermal protector automatically resets. Allow time (2 hrs.) for compressor to cool down so protector will reset. Restart and check for reason overheat occurred.

Check motor for open circuit, short circuit, grounded windings or burn out. Compressor may be seized; check refrigerant. If necessary, replace compressor.

Compressor

will not run

does not

try to start

Compressor contactor not closing.

Blown fuse or tripped breaker.

Low line voltage.

Compressor motor protector open.

Compressor defective.

If manual reset (high pressure), reset switch. (Switch opens at 400 psi and will not reset

High or low pressure switch open or defective.

Open room thermostat or control (no cooling required).

Loose wiring.

Low refrigerant charge. Check refrigerant pressures.

Compressor starts

but cuts out on low

pressure

Low pressure

switch activates

at 25 psig for R22,

50 psig for R410a

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Airflow restricted.

Restriction in refrigerant line.

Defective low pressure switch. Replace.

above 250 psi for R22 or 600/420 respectively for R410a). If auto reset (low pressure) does not reset and everything else is OK, replace switch.

Check room temperature. If temperature is proper, wait for thermostat to close.

Check all wire terminals and tighten as necessary.

Check for dirty evaporator coil, dirty filters, dampers closed, iced evaporator coil, improper belt, check motor amps, check duct design.

Check refrigerant pressure, check and adjust thermal expansion valve. If not functioning properly, check for pressure drop across the filter drier.

Page 46

Energy Recovery Unit with Packaged DX

Troubleshooting - General Refrigeration Circuit

Symptom Possible Cause Corrective Action

Refrigerant overcharge. Check pressures, charge by subcooling.

Compressor starts

but cuts out on high

pressure switch

High pressure

activates at

410 psig for R22,

600 psig for R410a

Compressor cuts out

on thermal overload

Condenser fan motor defective. Check fan motor.

Condenser coil inlet obstructed or dirty. Check coil and inlet clearances.

Air or non-condensables in system.

Defective high pressure switch. Replace.

Restriction in discharge or liquid line.

Condensing fan relay not pulling in. Replace.

Low voltage. Check voltage.

Sustained high discharge pressure.

High suction and discharge pressures.

Defective compressor overload.

Improper refrigerant charge. Check subcooling.

Check high side equalized pressure reading with equivalent outdoor temperature.

Check refrigerant line pressures, check thermal expansion valves.

Check running amperage and conditions described under ‘Low suction pressure’ symptoms.

Check thermal expansion valve setting, check for air in system.

If compressor is hot, allow compressor to cool for two hours. Recheck for open circuit.

Compressor hums,

but will not start

Improperly wired. Review wiring schematics.

Loose wiring. Check all connections and wires.

Defective start relay. Replace relay.

Motor windings damaged. Verify amp draw.

Improperly wired. Review wiring schematics.

Low line voltage. Check voltage.

Loose wiring. Check all connections.

Defective start or run capacitor.

Defective relay start. Replace relay.

Motor winding damaged. Verify amp draws.

Internal compressor mechanical damage. Replace.

Check run capacitor for compressor and fan motor.

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Page 47

Energy Recovery Unit with Packaged DX

Troubleshooting - General Refrigeration Circuit

Symptom Possible Cause Corrective Action

Refrigerant overcharge. Check pressures and subcooling.

Compressor noisy

or vibrating

High suction

pressure

Liquid floodback.

Tubing rattle.

Scroll compressor rotating in reverse (3 phase). Rewire for opposite rotation.

Worn or damaged compressor. Replace the compressor.

Improper mounting on unit base. Check that compressor is properly isolated.

Excessive load on evaporator coil.

Compressor is unloaded.

Expansion valve not secured to suction line.

Check thermal expansion valve setting. Check for refrigerant overcharge.

Dampen tubing vibration by taping or clamping. Carefully bend tubing away from contact where possible.

Check for high entering wet bulb temperature. Check for excessive air.

Check head pressure, check thermal expansion valve if not functioning properly, check pressure drop across filter drier.

Check the thermal expansion valve, ensure bulb is insulated.

Check superheat. If superheat is high, then valve is out of control and pegged wide open.

•Checkbulbforcontact. •Adjustvalveforsuperheat. •Replacevalvepowerheadorvalve.

High discharge

pressure

Thermostatic expansion valve pressure limit feature incorrect or inoperative. Overfeeding.

Room load too large. Reduce the load or add more equipment.

Overcharged. Check pressures and subcooling.

Thermal expansion valve setting.

Air inlet to condenser dirty or obstructed.

Condenser fan motor defective. Check condenser fan motor and capacitor.

Too much refrigerant. Remove excess refrigerant.

Non-condensable in system. Remove non-condensable from system.

Dirty condenser coil. Clean condenser coil.

Condenser fan not running or running backwards.

Discharge service valve partially closed. Open valve.

High load conditions. Add more equipment or reduce load.

Check bulb location and clamping. Adjust superheat. Replace expansion valve power head.

Check thermal expansion setting and calibrate superheat.

Check for proper clearances and possible air recirculating.

Check electrical circuit and fuse. Check fan cycling controls.

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Page 48

Energy Recovery Unit with Packaged DX

Troubleshooting - General Refrigeration Circuit

Symptom Possible Cause Corrective Action

Refrigerant undercharge. Check pressures and subcooling.

Low suction

pressure

Low discharge

pressure

Blower running backward.

Loose blower, pulley or belts. Check drive pulley alignment, belt tension.

Low entering air temperature (low load condition).

Refrigerant leak.

Evaporator dirty or iced up or airflow restricted.

Plugged liquid line filter-drier. Replace filter-drier.

Improper suction pressure regulator setting. Check setting and correct as required.

Expansion valve defective, superheat too high, or valve too small.

Moisture in system. Reclaim refrigerant, check for leaks, recharge.

Insufficient refrigerant charge.

Defective or improperly adjusted expansion valve.

Low suction pressure. See “Low suction pressure”.

Interchange any two wires from 3 phase disconnect.

Check entering air wet bulb conditions.

Check system for leaks. Repair leaks and add refrigerant.

Check defrost system. Clean the coil. Check fan operation. Check airflow.

Adjust valve for proper superheat or replace the expansion valve if too small or defective.

Check subcooling, check for leak. Repair leak and add refrigerant.

Check superheating and adjust thermal expansion valve.

Faulty condenser temperature controls.

Thermostat location or malfunction.

Improper refrigerant charge. Check subcooling, verify superheat.

Defective high or low pressure control. Check high or low pressure switch.

Liquid floodback. Possible tight bearings, see above.

Compressor short cycles

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Defective expansion valve. Check thermal expansion valve and superheat.

Poor air distribution. Check ductwork for recirculating.

High discharge pressure. See “High discharge pressure”.

Leaking discharge valves in compressor. See “High suction pressure”.

Low airflow at evaporator(s).

Incorrect unit selection (oversized). Contact factory.

Check condenser controls and reset to obtain desired condensing temperature.

Check thermostat, check heat anticipator setting.

Check blower operation and airstream restrictions.

Page 49

Energy Recovery Unit with Packaged DX

Troubleshooting - General Refrigeration Circuit

Symptom Possible Cause Corrective Action

Low or no

oil pressure

Compressor

loses oil

Low oil level (trapped oil in evaporator or suction line).

Excessive liquid refrigerant in the crankcase.

Worn oil pump. Replace the oil pump.

Worn compressor bearings. Replace the compressor.

Loose fitting on oil line or pump housing gasket leaking. (R22 only)

Compressor short cycling. Check low pressure control setting.

Refrigerant leak.

Short cycling. Check low pressure control settings.

Refrigerant flood back.

Improper piping or traps. Verify proper piping slopes.

Refrigeration undercharged. Check subcooling.

Thoroughly defrost evaporator. After defrost, observe level, add oil. Check for leaks. Check lines for proper slope and traps.

Adjust expansion valve for higher superheat. Check crankcase heater.

Check and tighten system. Check bottom plate or compressor.

Check system for leaks. Repair leaks and add refrigerant.

Check thermal expansion valve setting. Check for refrigerant overcharge.

Dirty filter or evaporator coil. Check filter, coil and airflow.

Dirty or clogged condenser coil. Check coil and airflow.

Running cycle is

too long or unit

operates

continuously

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Air or other non-condensables in system.

Defective compressor. See “High suction pressure”.

Restriction in suction and liquid line. Check for restrictions in refrigerant circuit.

Control contacts stuck. Check wiring.

Excessive load. Add more equipment or reduce room load.

Too low of a system thermostat setting or defective thermostat.

Check equalized high side pressure with equivalent outdoor temperature.

Adjust or replace thermostat.

Page 50

Energy Recovery Unit with Packaged DX

Troubleshooting - General Refrigeration Circuit

Symptom Possible Cause Corrective Action

Liquid line

is too hot

Liquid line is

frosted or wet

Suction line

is frosting

Frost on evap coil

Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or service information.

Refrigerant undercharge. Adjust the charge by subcooling.

High discharge pressure. See “High discharge pressure”.

Restriction in liquid line. Clear restriction upstream of point of frosting.

Insufficient evaporator airflow.

Restriction in suction or liquid line. Restriction upstream of point of frosting.

Malfunctioning or defective expansion valve. Check bulb of thermal expansion valve.

Hot gas bypass valve not functioning properly. Check valve. If defective, replace.

Manual hot gas bypass valve closed. Open valve.

Check airflow, check filters, check drive for loose parts or belts.

Page 51

Notes:

Energy Recovery Unit with Packaged DX

Page 52

Warranty

Greenheck warrants this equipment to be free from defects in material and workmanship for a period of one year from the shipment date. The energy recovery wheel is warranted to be free from defects in material and workmanship for a period of five years from the shipment date. Any units or parts which prove defective during the warranty period will be replaced at our option when returned to our factory, transportation prepaid.

Motors are warranted by the motor manufacturer for a period of one year. Should motors furnished by Greenheck prove defective during this period, they should be returned to the nearest authorized motor service station. Greenheck will not be responsible for any removal or installation costs.

As a result of our commitment to continuous improvement, Greenheck reserves the right to change specifications without notice.

#468151 IOM ERCH w/Packaged DX

Rev. 3, April 2012

Greenheck ERCH-20 Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual