Accurex XRV Operator’s Manual

Document 475597

Model XRV

Packaged Rooftop Ventilator

Installation, Operation and Maintenance Manual

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

General Safety Information

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

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

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

3. Unit must be securely and adequately grounded.

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

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

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

WARNING

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

DANGER

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

• If this unit is equipped with optional gas accessories, turn off gas supply whenever power is disconnected.

CAUTION

This unit is equipped with a compressed refrigerant system. If a leak in the system should occur, immediately evacuate the area. An EPA Certified Technician must be engaged to make repairs or corrections. Refrigerant leaks may also cause bodily harm.

CAUTION

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

Packaged Rooftop Ventilator 1

Table of Contents

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

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

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

Subassemblies ...............................5

Installation ................................. 6-9

Recommended Electrical and

Gas Supply Entry Locations ....................10

Piping Installation ............................11

Electrical Information. . . . . . . . . . . . . . . . . . . . . . . . . . 12

Control Center Components ....................13

Component Operation. . . . . . . . . . . . . . . . . . . . . . . . . 14

Optional Component Operation .............. 14-16

Factory-Installed Refrigeration System

Components ........................... 17-19

Start-Up – Unit ........................... 20-24

Start-Up – Components .................... 25-26

Troubleshooting ........................... 27-32

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

Maintenance Procedures ......................34

Reference

Venting Connection Locations ................35

Rated Airflow ..............................36

Maintenance Log .......................... 37-39

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

Packaged Rooftop Ventilator2

Receiving

This product may have been subject to road salt during transit. If so, immediately wash off all visible white reside from all exterior surfaces. Upon receiving the product, check to ensure all line items are accounted for by referencing the delivery receipt or packing list. Inspect each crate or carton for shipping damage before accepting delivery. Alert the carrier if any damage is detected, do not refuse shipment. The customer shall make notation of damage (or shortage of items) on the delivery receipt and all copies of the bill of lading which should be countersigned by the delivering carrier. If damaged, immediately contact your manufacturer’s representative. Any physical damage to the unit after acceptance is not the responsibility of the manufacturer.

Handling

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

Unpacking

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

Storage

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

The ideal environment for the storage of units and accessories is indoors, above grade, in a low humidity atmosphere which is sealed to prevent the entry of blowing dust, rain, or snow. Units designed for outdoor applications may be stored outdoors. All accessories must be stored indoors in a clean, dry atmosphere.

Indoor

Maintain temperatures evenly to prevent condensation. Remove any accumulations of dirt, water, ice, or snow and wipe dry before moving to indoor storage. To avoid condensation, allow cold parts to reach room temperature. Leave coverings loose to permit air circulation and to allow for periodic inspection.

The unit should be stored at least 3½ in. (89 mm) off the ﬂoor. Clearance should be provided to permit air circulation and space for inspection.

Outdoor

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

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

Inspection and Maintenance

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

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

Machined parts coated with rust preventive should be restored to good condition promptly if signs of rust occur. Immediately remove the original rust preventive coating with petroleum solvent and clean with lint-free cloths. Polish any remaining rust from surface with crocus cloth or ﬁne emery paper and oil. Do not destroy the continuity of the surfaces. Wipe thoroughly clean with Tectyl® 506 (Ashland Inc.) or the equivalent. For hard to reach internal surfaces or for occasional use, consider using Tectyl® 511M Rust Preventive, WD-40® or the equivalent.

Removing from Storage

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

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

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

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

Packaged Rooftop Ventilator 3

Product Overview

A horizontally conﬁgured High Percentage Outdoor Air unit designed for installation either indoors or outdoors. Each unit has multiple options for cooling and/or heating. The unit is designed to replace air that is exhausted from the building and also heat and cool, as needed. The air volume produced by the unit is constant, but can be optionally modulated to provide a variable air volume (VAV) and recirculation is also offered as an option.

Cooling

Units have the following cooling options available:

• Packaged DX

• Split DX

• Chilled water coil

• Air-source heat pump (ASHP)

Units with packaged DX are shipped fully charged with refrigerant and are ready for operation upon arrival.

Heating

There are three different optional heat sources that can be ordered for this unit:

• Indirect gas-ﬁred furnace with one or two sets of heat exchangers

• Electric heat with inﬁnitely variable SCR control

• Hot water coil

• Air-source heat pump (ASHP)

Airﬂow Arrangement

The unit is capable of Constant Air Volume (CAV), Variable Air Volume (VAV), 100% Outdoor Air and have recirculating air options.

Safety Listing

Models are listed per ANSI/UL 1995, Heating and Cooling Equipment and are ETL Certiﬁed.

Models and Capacities

The packaged rooftop ventilator is built on three different platform sizes.

Model Cooling Capacity

XRV-25 5 to 15 tons

XRV-45 15 to 30 tons

XRV-70 25 to 45 tons

Packaged Rooftop Ventilator4

Subassemblies

Blower

Either one or two plenum-type fans. All units are equipped with a plenum fan for Supply Air and a second may be selected for Exhaust (Relief) Air.

Coils - Evaporator coil (optional)

Condenser coil (optional, packaged DX only) Indoor coil (optional, air-source heat pump only) Outdoor coil (optional, air-source heat pump only) Water coil (optional) Reheat coil (optional)

Compressors

Each unit having packaged DX will have either one or two refrigerant compressors. Optionally, one of the compressors may be a digital scroll type compressor. Air-source heat pump units will have one inverter scroll compressor and may contain a second staged compressor.

Dampers

Motorized outdoor air damper, motorized recirculating damper. Optional return air damper. Optional gravitytype exhaust damper.

Optional Barometric Relief Damper

Used during economizer mode of the unit when building pressure increases, relief damper will open due to over pressurization.

Electric Heater

An SCR controlled electric heater (not shown) is available on the units. It has its own control panel and may require a separate power supply. See unit-speciﬁc wiring diagram.supply and has its own control panel. See unit-speciﬁc wiring diagram.

Low Sound Condenser Fans

(optional)

Coils

(optional)

Supply Filters - All housings are available with a ﬁlter

bank depth of either 2 or 4-inch.

Indirect Gas-Fired Furnace - Furnace model PVG is

available on XRV-25 and XRV-45. Model XRV-70 uses furnace model PVF 200-600 or model HMA 700-800.

Packaged DX System - Any unit may be ordered with a

packaged DX system. Housing size XRV-25 will include either one or two compressors; XRV-45 will include two compressors; housing size XRV-70 will include four compressors; a condenser coil(s) and evaporator coil(s) and all required components. Units that have packaged DX are charged with R410A refrigerant. Do not use tools or parts designed for other refrigerants on these units.

Air-Source Heat Pump - Units having an air-source heat

pump will include either one or two compressors, an indoor and outdoor coil, and all required components. Air-source heat pump units are charged with R410A refrigerant. Do not use tools or parts designed for other refrigerants on these units. Option not available on the RV-110 and RVE-180.

Split DX

The unit may be ordered with a split DX system for connection to a building cooling system.

Vestibule

Some units may be ordered with a factory-assembled vestibule that is to be ﬁeld-attached to the side of the unit. See lifting instructions.

Outdoor Air Filters

Weatherhood Filters

(metal mesh)

Condenser Coils

(optional)

Packaged DX Compressors

(optional)

Furnace Vest Plate

and

Furnace Control Center

(optional)

Main Control

Center

Plenum-Type

Supply Air Blower

Indirect Gas-Fired Furnace

(optional)

Outdoor Air

Damper

Recirculating

Damper

Plenum-Type

Exhaust Air Blower

Packaged Rooftop Ventilator 5

Installation

Typical Unit Weights and Dimensions

Component Access

1 Optional Inverter Compressor

2 Optional Compressor/Electrical

3 Optional Gas Furnace/Optional Electric Heater

4 Electrical

5 Supply Blower

6 Coil

7 Filters

(A)

Condensing

Section

(B)

Unit Size

XRV-25 5-15 59.3 52.5 98.6 22.1 30.1 2,700

XRV-45 15-30 72.5 68.2 109 27.7 30.1 4,500

XRV-70 20-45 90 68 156 22/27^ 30 6,400

All dimensions are shown in inches. Weight is shown in pounds and includes largest supply and exhaust fans, PDX with reheat, largest indirect-gas ﬁred furnace, and all dampers. Actual weights will vary based on the unit conﬁguration. * Only available with powered exhaust ** Only available without barometric relief

Only available with barometric relief ^ Above 12,000 cfm

Nominal tonnage

(tons)

Height

(H)

Width

(W)

Length

(L)

Intake

Nominal

weight

(lbs)

Outdoor

Intake

End

Supply

Discharge

Bottom

Side

Return

Intake

Bottom,

End**

Side*

Exhaust

Discharge

End

Side*

Service Clearances

CC End

ACS

Clearance

OA End

Unit Size ACS CC End OA End

XRV-25 40 42 42 24 18 30

XRV-45 36 58 42 24 18 30

ACS = Access CC = Control Center NA = Non-Access OA = Outdoor Air Weatherhood

Packaged Rooftop Ventilator6

XRV-70 36 52 58 24 18 30

All dimensions are shown in inches. *NA from Unit = no condensing section or piping vestibule **NA from CS = condensing section ***NA from Vest = piping vestibule

*NA

from

Unit

**NA from

***NA

from

Vest

Installation

Additional Clearances for Packaged DX Units

Packaged DX units require additional clearance because they must have unrestricted air movement around the condenser coil and condenser fans. Hot air is being discharged from the condenser fans during operation. Enough clearance must be provided to avoid recirculation or coil starvation. When equipped with condenser coils, the unit should never be placed under an overhang or inside a building. A minimum of 48inches above the condenser fans is acceptable, but unobstructed is strongly recommended.

Minimum 48 inches clearance

Condenser Fans

Minimum 18 inches

clearance

Condenser Coil

End view of rooftop unit with Packaged DX

Handling Concerns for Packaged DX or Air-Source Heat Pump

Units with PDX or ASHP have a system that is pressurized with refrigerant. If damage occurs, the refrigerant 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.

Before Lifting

Before lifting, be sure that all shipping materials have been removed from the unit.

Vestibule

Determine whether or not the unit has a vestibule that must be ﬁeld-attached to the side of the unit. Vestibules are shipped assembled but detached from the unit. They have lifting lugs on them so they can also be lifted by crane, but the installed location of the unit may make it preferable to install the vestibule on the unit prior to lifting.

Field Power Access

Determine where high voltage and low voltage wiring is to be brought into the cabinet. If wiring is to be brought into the cabinet through the ﬂoor, see Alternate Supply Entry Locations in this manual. If unit is to be installed on a roof, cut access openings in the roof deck as needed.

Additional Clearances for Air Source Heat Pump

IMPORTANT

Air-source heat pumps are equipped with a defrost cycle to remove ice from the outdoor coil. During defrost cycles, melted water may drip from the bottom of the refrigeration section under the outdoor coil. In cold climates, proper drainage/heat tape must be installed under the outdoor coil to prevent the buildup of ice on the roof.

Air-source heat pump units require additional clearance because they must have unrestricted air movement around the outdoor coil and outdoor fans. Enough clearance must be provided to avoid recirculation or coil starvation. Air-source heat pump units should never be placed under an overhang or inside a building. A minimum of 48-inches above the outdoor fans is acceptable, but unobstructed is strongly recommended.

Packaged Rooftop Ventilator 7

Installation

Lifting

1. Ensure that all shipping materials have been removed from unit.

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

3. Unit must be lifted by all lifting lugs provided at top of unit.

4. Spreader bars must span the unit to prevent damage to the cabinet by the lift cables.

5. Never rest the spreader bar on the unit.

WARNING

Spreader bars are required to prevent damage to the cabinet, failure to do so can result in damage that is the installer’s responsibility.

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

7. Never lift unit by weatherhood.

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 top of the curb prior to lifting the unit and setting on the curb.

11. Do not use fork lifts for handling unit.

Roof Curb Mounting

Roof curb details, including duct locations and dimensions, are to be found in the roof curb assembly instructions.

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 adapters) and require ﬁeld assembly (by others). Assembly instructions are included with the curb kit.

2. Install curb. Locate curb over roof opening and fasten in place. 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 the curb as required to level. Install gasketing on top surface of curb (provided by others).

3. Install ductwork. Installation of all ducts should be done in accordance with SMACNA and AMCA guidelines. Duct adapters are 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 level.

5. Fasten the unit, Fasten the unit to the curb/ equipment support(s) using appropriate methods. The installer is responsible for determining appropriate support and fastening methods to ensure compliance with all applicable codes.

6. Install vestibule. If unit was ordered with a vestibule and it has not yet been attached to the unit, caulk and attach the vestibule at this time.

Packaged Rooftop Ventilator8

Typical Unit with Condensing Section and

Factory-Supplied Curb Kit

Installation

Optional Piping Vestibule

If the unit was ordered with the vestibule, the NA (NonAccess side) clearance dimension must be measured from the vestibule.

Typical Unit with Piping Vestibule and

Factory-Supplied Curb Kit

Rail Mounting and Layout

• The units may be installed on rails provided and installed by others. Ensure that rails are designed to handle the weight of the unit and provide proper load distribution on building supports.

• Make sure that rail positioning does not interfere with the openings on the unit.

• 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.

Ductwork Conﬁgurations

NOTE

Downblast Discharge Ductwork - whenever

downblast discharge is used, the ductwork directly beneath the unit must be connected with either a “T” or an “L” configuration and the area directly beneath the heat source must not have any openings such as louvers or grates.

Typical Unit Installed on Rails Supplied by Others

No louvers or grates

Packaged Rooftop Ventilator 9

Recommended Electrical and Gas Supply Entry Locations

Manufacturer recommends that electrical service and gas supply be brought into the cabinet through the end wall, as shown below. There are three penetrations into the cabinet that are required; one for high voltage supply wiring, one for low voltage control wiring and one for either gas supply or high voltage supply wiring for an electric heater.

Optional Unit Disconnect

Indirect Gas Supply Location

Field Wiring

Recommended Gas and Electric Supply Entry Locations

Alternate Supply Entry Locations

Each installation is unique and as a result, alternate entry locations may be ﬁeld-located. Before using any alternate entry location, verify the suitability of the location and ensure the use of an alternate location does not interfere with unit wiring, components or functionality.

WARNING

Never drill holes in the roof of the unit! There is high voltage wiring located between the inner and outer roof panels. Damage to the wiring could cause severe bodily harm or death.

Optional Gas Piping

Units with indirect gas-ﬁred furnaces require ﬁeldsupplied and installed gas supply piping.

Housing

Size

Total Heating

Capacity

(Input in MBH)

Gas

Connection

Size

Max Gas Pressure

100

150

XRV-25

200

¾” NPT 14 in. wg.

250

300

XRV-45

¾” NPT 14 in. wg.400

500

200

250

300

350

XRV-70

400

¾” NPT 14 in. wg.

500

600

700

800

Gas Connections

If this unit is equipped with an indirect gas-ﬁred furnace, connection to an appropriate gas supply line will be required. For complete information on installation procedures for the optional gas furnace, refer the PVF/PVG Indirect Gas-Fired Heat Module Installation, Operation, and Maintenance Manual.

Ground

Joint

Gas Cock

From Gas Supply

Bleeder Valve or 1/8 in Plugged Tap

Typical Gas Supply Piping Connection

Packaged Rooftop Ventilator10

Union

8 in. Trap

Gas to

Controls

Piping Installation

Optional Coil Piping

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.

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. 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. 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. Water coils are not normally recommended for use with entering air temperatures below 40°F. 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. If glycol or brine solutions are not used, coils must be drained when freezing conditions are expected. If required,

vent and drain connections must be fieldpiped, external to the unit.

4. 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.

5. For chilled water coils, the condensate drain pipe should be sized adequately to ensure the condensate drains properly. Refer to Drain Trap section.

Direct Expansion (DX) Coils (Split DX)

1. Piping should be in accordance with accepted industry standards. Pipework should be supported independently of the coils. Undue stress should not be applied at the connection to coil headers.

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

3. When connecting suction and liquid connections make sure the coil is free from all foreign material. Make sure all joints are tight and free of leakage. Be sure to replace factory-installed grommets around coil connections if removed for piping.

4. Manufacturer does not supply compressor, condensing units, or thermal expansion valve (TXV) with standard models. For further instruction on DX coil installation and operation contact your compressor and/or condenser manufacturer.

Condensate Drain Trap

This unit is equipped with a stainless steel condensate pan with a stainless steel connection. It is important that the drain connection be ﬁtted with a P trap to ensure proper drainage of condensate while maintaining internal static pressures and to prevent migration of sewer gas back into the unit.

A P trap assembly (kit) is supplied with each unit and is to be assembled and installed as local conditions require and according to the assembly instructions provided with the P trap. If local and area codes permit, the condensate may be drained back onto the roof, but a drip pad should be provided beneath the outlet. If local and area codes require a permanent drain line, it should be fabricated and installed in accordance with Best Practices and all codes.

In some climates, it will be necessary to provide freeze protection for the P trap and drain line. The P trap should be kept ﬁlled with water or glycol solution at all times and it should be protected from freezing to protect the P trap from damage. If severe weather conditions occur, it may be necessary to fabricate a Ptrap and drain line of metal and install a heat tape to prevent freezing.

Condensate Overﬂow Switch

This unit is equipped with an optional factory-mounted condensate overﬂow switch. In the event that a high level of condensate is detected, a dry contact will be powered (24 VAC). This dry contact can be used for ﬁeld monitoring of condensate levels. All monitoring and control shall be provided by others.

Packaged Rooftop Ventilator 11

Electrical Information

WARNING

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

WARNING

To prevent injury or death due to electrocution or contact with moving parts, lock disconnect switch open. For units with a gas furnace, if you turn off the power supply, turn off the gas.

IMPORTANT

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

IMPORTANT

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

IMPORTANT

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

CAUTION

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

DANGER

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

CAUTION

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

Determine the Size of the Main Power Lines

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

Determine the Size of Electric Heater Wiring

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

Provide the Opening(s) for the Electrical Connections

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

Connect the Power Supplies

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

Wire the Optional Convenience Outlet

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

Connect Field-Wired Low Voltage Components

Most factory-supplied electrical components are prewired. To determine what electrical accessories require additional ﬁeld-wiring, refer to the unit-speciﬁc wiring diagram located on the inside of the control center access door.

The low voltage control circuit is 24 VAC and control wiring should not exceed 0.75 ohms.

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

If wire resistance exceeds 0.75 ohms, an industrialstyle, 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. 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.

Field-Provided Disconnect

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

Packaged Rooftop Ventilator12

Control Center Components

Main Control Center Components

Image represents a typical XRV installation. Components and locations will vary on housing size and conﬁguration.

High Voltage Side

1. Power distribution block; high voltage supply is terminated here

2. Fuse holders

3. Phase monitor

4. Compressor motor contactors

5. Condensing fan motor contactors

6. Wheel motor contactor

7. Transformer

8. Unit Disconnect

Low Voltage Side

9. Microprocessor controller

10. Monitoring points

11. Low voltage terminal strip

12. Relays

13. Dirty ﬁlter switch

14. Outdoor airﬂow monitor

15. Exhaust airﬂow monitor

16. Digital scroll controller

LOW VOLTAGE SIDE

Accessible via compressor door

HIGH VOLTAGE SIDE

Accessible via control center door

5 6

4 5

Optional Indirect Gas-Fired Furnace

Note: In some models, two furnaces are installed to provide greater output. When two furnaces are installed, they are in parallel and both will operate at the same time and the same output. Both furnaces will have identical controls.

1. Single-stage valve

2. Modulating valve

3. PCOE expansion board

4. Ignition controller

5. Transformer

6. Combustion blower

7. Burner manifold

8. Collector box

Dual furnaces shown. Available on housing 80 and 120 with furnace capacities 500 MBH or higher.

For further information on the optional furnace and its control center, see the Indirect Gas-Fired Heat lOM shipped with the unit.

Packaged Rooftop Ventilator 13

Component Operation

Optional Component Operation

Phase Monitor

The unit control circuitry includes a phase monitor that constantly checks for phase reversal, phase imbalance, loss of phase or a power brownout. When it detects a fault, it cuts off the 24 VAC that goes to the low voltage terminal strip, thereby shutting off all motors.

Variable Frequency Drive (VFD)

If a VFD was provided and installed at the factory, it has been pre-set to control the speed of the blower motor for optimum performance. The motor speed needs to be veriﬁed during test and balance of the unit.

If the system was conﬁgured for Constant Air Volume (CAV), the VFD will operate in an ON/OFF fashion and the speed of the motor will not change. If the system was conﬁgured for Variable Air Volume (VAV), the microprocessor will constantly monitor operating conditions and provide a signal to the VFD, changing the VFD output as needed.

The VFD may alternatively be connected to an external signal such as provided by a BMS and be operated by a 2-10 VDC or a 4-20 mA input.

Supply Fan VFD Sequence

Optional Room CO2 Sensor: The microprocessor will modulate the supply fan based on a comparison of the CO2 set point to the actual CO2 levels reported from the sensor. Mechanical high static protection cutoffs must be installed by others to protect the system and equipment from over-pressurization.

Optional Duct Static Pressure Sensor: The microprocessor will modulate the supply fan based on a comparison of the duct static pressure set point to the actual duct static pressure level reported from the sensor. Mechanical high static protection cutoffs must be installed by others to protect the system and equipment from over-pressurization. The manufacturer does not assume responsibility for this.

Optional Building Static Pressure Sensor: The supply fan is modulated based upon the signal from a building static pressure sensor. The microprocessor will modulate the supply fan based on a comparison of the building static pressure set point to the actual building static pressure level reported from the sensor.

Optional Single Zone VAV: The microprocessor will use a space mounted temp sensor to vary heating and cooling capacity and the airﬂow delivered by the fan to maintain room-air temp at a desired set point.

Optional 0-10 VDC by others to VFD: Supply fan is modulated by a 0-10 VDC, ﬁeld-provided by others.

Exhaust Fan VFD Sequence

Optional Building Static Pressure Sensor: The exhaust fan is modulated based upon the signal from a building static pressure sensor. The microprocessor will modulate the exhaust fan based upon a comparison of the building static pressure level reported from the sensor.

Optional Outdoor Air Damper Tracking: The microprocessor will proportionally modulate the exhaust fan based upon the outdoor air damper position.

Optional Supply Tracking: The microprocessor will proportionally modulate the exhaust fan based upon the supply fan.

Optional 0-10 VDC by Others to VFD: The supply fan is modulated by a 0-10 VDC provided by others in the ﬁeld.

Outdoor Air and Recirculated (Recirc) Air Damper Sequence

Optional Room CO2 Sensor: The microprocessor will proportionally modulate the OA/RA dampers based upon a comparison of the CO2 set point to the actual CO2 level reported from the sensor. As the CO2 level rises, the controller will proportionally modulate the outdoor air damper open, between the minimum and maximum OA position.

Optional Building Pressure: The OA/RA dampers will modulate based upon the signal from a building static pressure sensor. The controller will modulate the dampers, between the minimum and maximum OA positions, based upon a comparison of the building static pressure set point to the actual building static pressure level reported from the sensor.

Exhaust Fan Only Power

The exhaust fan will have a dedicated power circuit where in the case of a power outage, the exhaust fan will still run. A phase monitor will detect an outage or power loss and open the contact, disconnecting all power to the unit and controller. An external signal will need to be sent to a relay to power the exhaust fan, enabling the fan to run at a maximum speed. This sequence is NOT to be used for high temperature exhaust applications.

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.

Packaged Rooftop Ventilator14

Optional Component Operation

Electronically Commutated (EC) Condenser Fans with Standard Scroll or Digital Scroll Compressors

The EC condenser fan will modulate up and down to maintain the highest liquid line pressure. The factory set points are: Set (left

dial): 23 barg; Diff (right dial): 5 barg.

Fan operation with these set points are as follows. The fan will be at max speed (~1140 rpm) when the highest liquid line saturation temperature is 118°F (410psig, 28 barg). The fan remains at max speed if the pressure is higher than 410psig (28 barg). The fan will be at min speed (~180rpm) when the highest liquid line saturation temperature is 105°F (340 psig, 23 barg). Below this pressure, the fan will be off. The fan modulates linearly between the min and max speeds. If unit is selected with inverter compressor or air-source heat pump, reference the supplemental

Reference Guide for Microprocessor Controller.

Set (left dial): 23 barg; Diff (right dial): 5 barg

Airﬂow Monitor

A factory-wired, mounted, and powered airﬂow monitoring system is provided in the outdoor and/or exhaust air streams. The airﬂow control system offers the following functionality:

• Display of outdoor and/or exhaust airﬂow rate in

actual cubic feet per minute (CFM) or actual liters per second (LPS) on a 16 character LCD display.

• Two conﬁgurable analog outputs for transmitting

outdoor and/or exhaust airﬂow rate, outdoor air temperature, or a proportional-integral-derivative (PID) control signal based on an outdoor airﬂow set point.

• A conﬁgurable digital output that operates based on

an airﬂow set point or range.

Operation

Outdoor and/or exhaust airﬂow monitoring is accomplished using two thermal dispersion sensors that accurately measure airﬂow velocity down to zero feet per minute (fpm). The airﬂow controller takes the average measurement for two sensor conﬁgurations, and determines the outdoor airﬂow rate based on the effective intake area. Field calibration of the outdoor airﬂow monitoring device determines the effective intake area of the unit.

For additional information on how to navigate through the airﬂow controller menus, refer to technical manuals from GreenTrol® Automation Inc. at www.greentrol.com.

IMPORTANT

For the airflow monitoring device to perform as intended, field calibration is required. Calibration of the airflow monitoring device requires an independent measurement of airflow and should be performed when the system undergoes test and balance.

Air-Source Heat Pump

IMPORTANT

Melted water from snow accumulation on the unit roof can be sucked into outdoor fans, resulting in ice formation on fan blades under certain conditions. Remove snow accumulation from the unit roof and outdoor coil section after snow storms.

Operating Conditions and Limitations

To operate in Cooling mode, the following conditions must be true:

1. Supply air temperature above minimum low supply temperature limit (35°F)

2. Outside air temperature above the cooling ambient lockout (55°F, adj.)

To operate in Heating mode, the following conditions must be true:

1. Supply air temperature below maximum high supply temperature limit (120°F)

2. Supply air temperature above 35°F

3. Outside air temperature above the low ambient lockout (10°F, adj.)

For more information on air-source heat pump operation, reference the supplemental Reference Guide

for Microprocessor Controller.

Packaged Rooftop Ventilator 15

Optional Component Operation

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.

Microprocessor Control

The microprocessor controller is speciﬁcally designed and programmed to optimize the performance of the unit with supplemental heating and cooling. This option ensures that the outdoor air is conditioned to the desired discharge conditions. The controller and accompanying sensors are factory-mounted, wired and programmed. Default settings are pre-programmed, but are easily ﬁeld-adjustable.

The microprocessor controller can be interfaced with a Building Management System through LonWorks®, BACnet®, or ModBus.

Please refer to the Installation, Operation and Maintenance manual for detailed information.

Hot Gas Bypass Valve (standard scroll)

On units equipped with hot gas bypass, hot gas from the compressor is injected into the liquid line of the evaporator coil after the thermostatic expansion valve. This process starts to occur when suction gas temperatures drop below 28°F, which is 32°-34°F coil surface temperature. Hot gas helps the evaporator coil from freezing up and the compressor from cycling. The valve needs to be adjusted to exact speciﬁcations once unit is installed in the ﬁeld.

Hot Gas Reheat Valve

Units equipped with a reheat coil use a three-way valve with actuator to control the supply air discharge temperature of the unit during dehumidiﬁcation mode. The unit controller provides a 0-10VDC signal to control the amount of reheat to meet the supply temperature set point.

Controls by Others

The reheat coil needs to be purged to ensure adequate oil return. It is recommended that every six hours of reheat compressor run time should initiate a six minute purge cycle. During the purge cycle, the reheat valve should be modulated to 100% open to the reheat coil.

Unoccupied Recirculation Damper

The unoccupied recirculation option provides a recirculation damper from the return air intake to the supply airstream. If equipped with a room temperature and/or relative humidity sensor, the unit can cycle on to maintain unoccupied room set points if there is a call for unoccupied heating, cooling, or dehumidiﬁcation. During the unoccupied mode, the supply and exhaust (if equipped) fans will be off unless there is a call for cooling, heating, or dehumidiﬁcation in the space.

Vapor Tight Lights

Packaged Rooftop Ventilator16

Factory-Installed Refrigeration System Components

Packaged DX Cooling with Three Way Hot Gas Reheat and Hot Gas Bypass

1. Compressor

2. High Limit Pressure Switch

The switch opens when refrigerant pressure increases above the set point in the discharge line. A manual reset is then required.

3. Hot Gas Reheat Valve (optional)

Units equipped with a reheat coil use a threeway valve with actuator to control the supply air discharge temperature of the unit during dehumidiﬁcation mode. The unit controller provides a 0-10 VDC signal to control the amount of reheat to meet the supply temperature set point

4. Hot Gas Reheat Coil (Optional)

5. Hot Gas Reheat Check Valve (Optional)

6. Condenser Fans

7. Condensing Coil

8. Liquid Receiver (Optional)

9. Liquid Line Filter Drier

10. Sight Glass

11. Fan Cycle Switch(es)

The switch(es) open or close based on liquid refrigerant pressure to control the condensing fans to maintain liquid pressure.

12. Thermostatic Expansion Valve (TXV)

Each unit is equipped with a TXV on each refrigerant circuit. The valve controls the ﬂow of liquid refrigerant entering the evaporator coil by maintaining a constant, factory-set superheat of 10°F. The valve is adjustable and is located on the side of the evaporator coil and can be accessed through the coil access panel.

13. Evaporative Coil

14. Low Limit Pressure Switch

The switch is installed on the suction line and disables the DX system when the suction pressure drops below the set point. The switch will auto reset when the pressure rises above the auto-reset set point.

15. Service Access Ports

16. Hot Gas Bypass Manual Shut Off Valve (Optional)

Used to disable hot gas bypass for service and troubleshooting procedures.

17. Hot Gas Bypass Valve (Optional)

On units equipped with hot gas bypass, hot gas from the compressor is injected into the liquid line of the evaporator coil after the TXV.

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 115 PSIG for R-410A (the valve will feel warm to the touch). Adjustments are made by ﬁrst removing the cap on the bottom of the valve and then turning the adjusting stem clockwise to increase the setting pressure (counterclockwise to decrease). Allow several minutes between adjustments for the system to stabilize. When adjustment is complete, replace the cap on the valve.

18. Pressure Gauge & Transducer (Optional EC

condenser fans only)

See Optional Electronically Commutated (EC)

Condenser Fans under the component operation.

Packaged Rooftop Ventilator 17

Factory-Installed Refrigeration System Components

Air-Source Heat Pump with Three Way Hot Gas Reheat

Outdoor Airﬂow

EXV

HCV

HRV

HPS

LPS

ACC

Compressor

4WV

Outdoor Coil

Supply Airﬂow

Hot Gas Reheat Coil

FDS

Indoor Coil

Outdoor Airﬂow

4WV

Outdoor Coil

TXV

Supply Airﬂow

Indoor Coil

FDS

ACC

LPS

HPS

Compressor

Packaged Rooftop Ventilator18

Factory-Installed Refrigeration System Components

1. Compressor

2. High Limit Pressure Switch

The switch opens when refrigerant pressure increases above the set point in the discharge line. A manual reset is then required.

3. Hot Gas Reheat Valve (optional)

4. Hot Gas Reheat Coil (Optional)

5. Hot Gas Reheat Check Valve (Optional)

6. Outdoor Fans

7. Outdoor Coil

8. Refrigeration Accumulator

9. Liquid Line Filter Drier

10. Sight Glass

11. Four Way Reversing Valve

Each compressor circuit is equipped with a reversing valve to reverse the direction of refrigerant ﬂow, switching the unit between heating and cooling mode.

12. Electronic Expansion Valve (EXV) or Thermostatic Expansion Valve (TXV)

An expansion valve is provided on each refrigerant circuit. This valve controls the ﬂow of liquid refrigerant entering the indoor and outdoor coils by maintaining a constant superheat. The TXV is adjustable. Both the EXV and TXV are located on the side of the outdoor coil and can be accessed through the refrigeration system access panel.

13. Indoor Coil

14. Low Limit Pressure Switch

15. Service Access Ports

Typical port locations are shown. Additional valves may be present in the system.

16. Refrigerant Pressure Transducers

Packaged Rooftop Ventilator 19

Start-Up Unit

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.

CAUTION

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.

CAUTION

Do not operate without the filters and birdscreens installed. They prevent the entry of foreign objects such as leaves, birds, etc.

CAUTION

Do not run unit during construction phase. Damage to internal components may result and void warranty.

WARNING

• Unit was factory tested. All blowers, fans, and compressors are set-up to run correctly 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.

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

WARNING

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.

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 No. ___________________________________

Unit Serial No. ____________________________________

Compressor 1 Model No. __________________________

Compressor 2 Model No. __________________________

Compressor 3 Model No. __________________________

Compressor 4 Model No. __________________________

Start-Up Date ____________________________________

Start-Up Personnel Name __________________________

Start-Up Company ________________________________

Phone Number ___________________________________

Packaged Rooftop Ventilator20

Start-Up Unit

Pre-Start-Up Checklist

o Remove any foreign objects that are located in the

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 by hand and ensure no parts

are rubbing.

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.

o Verify that non-motorized dampers open and close

properly.

o Check the tightness of all factory wiring

connections.

o Verify proper drain trap installation. 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. o Inspect all coils within the unit. Fins may get

damaged in transit or during construction. Carefully straighten fins with a fin comb.

Electrical

oDisconnect and lock-out all power switches. o Verify control wire gauge. o All field-mounted sensors and instruments are

installed and wired.

o Unit controls are off. o Electrical service matches unit voltage. o Electrical field wiring is complete. o All electrical connections are tightened. o Compressor and motor breakers or fuses are open

(disabled).

o Main power is wired to the disconnect. o Discharge air sensor is installed per wiring

instructions.

o Space temperature and humidity sensors are

installed per if selected with unit. Compressors o This unit contains an external crankcase heater for

each standard or digital scroll compressor. The

variable speed compressor uses internal stator

heating. Each compressor 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. oCompressor shipping brackets are removed if

provided.

IG Furnace o If there is an indirect gas-fired furnace in this unit,

refer to the manual provided with this unit for PreStart-Up information.

o Gas piping is complete and gas lines are purged. o Gas venting is in place.

Hot Water/Chilled Water Coils

o Chilled water piping system is complete. o Hot water piping system is complete. o Control valves are installed, wired, and operating

properly.

o Water coils are balanced to design GPM. o Water system is free of air.

SPECIAL TOOLS REQUIRED

• Voltage Meter (with wire probes)

• Amperage Meter

• Pressure Gauges – (refrigerant)

• Tachometer

• Thermometer

• Incline manometer or equivalent

Start-Up Procedure

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.

o Make sure Pre-Start-Up checklist is complete.

o Jumper R to G, R to Y1, and R to Y2 (if applicable)

on the control board.

o Turn the disconnect on. After 3 minutes

compressors will come on. Make sure all fans and compressors are rotating the correct direction.

o Allow the unit to run until the refrigerant system

stabilizes. Approximately 1-2 minutes.

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

Packaged Rooftop Ventilator 21

Start-Up Checklist

Line Voltage. Check at unit disconnect.

L1-L2 Volts L2-L3 Volts L1-L3 Volts

Motor Amp Draw

Supply Motor 1 Amps L1 Amps L2 Amps L3 Amps

Supply Motor 2 Amps L1 Amps L2 Amps L3 Amps

Exhaust Motor 1 Amps L1 Amps L2 Amps L3 Amps

Exhaust Motor 2 Amps L1 Amps L2 Amps L3 Amps

Fan RPM Correct fan rotation direction?

Supply Fan RPM Supply Fan Yes / No

Exhaust Fan RPM Exhaust Fan Yes / No

Condensing Fans

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

Condensing Fan 4 L1 Amps L2 Amps L3 Amps

Compressors

Outdoor Air Temperature Deg F Outdoor Air Relative Humidity % RH

Return Air Temperature Deg F Return Air Relative Humidity % RH

Compressor 1 Compressor 2 Compressor 3 Compressor 4

L1 Amps Amps Amps Amps

L2 Amps Amps Amps Amps

L3 Amps Amps Amps Amps

Crankcase Heater Amps Amps Amps Amps

Superheat Should be between 7º and 9ºF

Subcooling Should be between 10º and 12ºF

Discharge Pressure Should be between 300 and 500 PSIG

Suction Line Pressure Should be between 100 and 135 PSIG

Liquid Line Temp. Deg. F Deg. F Deg. F Deg. F

Suction Line Temp. Deg. F Deg. F Deg. F Deg. F

Moisture Indicating Sight Glass

Liquid Visible Yes / No Yes / No Yes / No Yes / No

Color of Center Dot Purple / Pink Purple / Pink Purple / Pink Purple / Pink

Hot Gas Bypass Operational Yes / No NA NA NA

Deg. F Deg. F Deg. F Deg. F

PSIG PSIG PSIG PSIG

Packaged Rooftop Ventilator22

Start-Up Checklist - Packaged Direct Expansion (DX)

Compressor 1 Compressor 2 Compressor 3 Compressor 4

L1 Amps Amps Amps Amps

L2 Amps Amps Amps Amps

L3 Amps Amps Amps Amps

Crankcase Heater Not present on inverter compressor

Superheat Should be between 8º and 12ºF

Subcooling Should be between 8º and 12ºF

Discharge Pressure Should be between 300 and 500 PSIG

Suction Line Pressure Should be between 100 and 135 PSIG

Liquid Line Temp. Deg. F Deg. F Deg. F Deg. F

Suction Line Temp. Deg. F Deg. F Deg. F Deg. F

Moisture Indicating Sight Glass

Liquid Visible Yes / No Yes / No Yes / No Yes / No

Color of Center Dot Purple / Pink Purple / Pink Purple / Pink Purple / Pink

Hot Gas Bypass Operational Yes / No / NA NA NA NA

Amps Amps Amps Amps

Deg. F Deg. F Deg. F Deg. F

PSIG PSIG PSIG PSIG

Packaged Rooftop Ventilator 23

Start-Up Checklist - Air-Source Heat Pump (ASHP)

Compressor 1 Compressor 2

Compressors

L1 Amps Amps

L2 Amps Amps

L3 Amps Amps

Crankcase Heater NA Amps

Cooling

Superheat Should be between 10º and 20ºF (0% reheat) or

should be between 10º and 30ºF (100% reheat)

Subcooling Should be between 10º and 15ºF (0% reheat) or

should be between 2º and 10ºF (100% reheat)

Discharge Pressure Should be between 250 and 500 PSIG

Suction Line Pressure Should be between 96 and 155 PSIG

Liquid Line Temp Deg. F Deg. F

Suction Line Temp Deg. F Deg. F

Moisture Indicating Sight Glass

Liquid Visible Yes / No Yes / No

Color of Center Dot Purple / Pink Purple / Pink

Heating

Superheat Should be between 10º and 20ºF

Subcooling Should be between 10º and 20ºF

Discharge Pressure Should be between 250 and 500 PSIG

Suction Line Pressure Should be between 96 and 155 PSIG

Liquid Line Temp Deg. F Deg. F

Suction Line Temp Deg. F Deg. F

Moisture Indicating Sight Glass

Liquid Visible Yes / No Yes / No

Color of Center Dot Purple / Pink Purple / Pink

Note: Unit may not run at 100% heating mode in ambient temperatures over 70°F (21°C). Modulate compressor as necessary to keep unit running.

Deg. F Deg. F

PSIG PSIG

Deg. F Deg. F

PSIG PSIG

Packaged Rooftop Ventilator24

Start-Up Components

Fan

The fan should be checked for free rotation. If any binding occurs, check for concealed damage and foreign objects in the fan housing.

CAUTION

When operating conditions of the fan are to be changed (speed, pressure, temperature, etc.), consult manufacturer to determine if the unit can operate safely at the new conditions.

Supply Fan (Plenum Type)

The unit contains one plenum supply fan located on the end of the unit opposite the outdoor air intake and may optionally have a relief air blower which is referred to as an exhaust blower in this document. Efﬁcient fan performance can be maintained by having the correct offset.

Offset: Proper offset, or overlap, is adjusted by loosening the wheel hub from the shaft and moving the wheel to the desired position along the shaft. The transition between the inlet cone

and the wheel should be as shown; there is a smooth feel to the proﬁle when moving one component to the other.

Tolerance

(inches)

Fan Size

Wheel

Offset

Inlet

Cone

Offset

(inches)

ER35C 5/32 ± 1/32

ER45C 3/16 ± 1/32

ER50C 13/64 ± 1/32

ER56C 1/4 ± 1/32

Refer to the respective Installation, Operation and Maintenance Manual shipped with this unit for additional start-up and maintenance information regarding the plenum fan.

Fan Wheel Rotation Direction

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.

If the wheel is rotating the wrong way, direction can be reversed by interchanging any two of the three electrical leads. Check for unusual noise, vibration or overheating of the bearings. Refer to the Troubleshooting portion of this manual if a problem develops.

Supply/Exhaust Fan

The optional exhaust fan is a direct-drive plenum type. Fan speed is controlled by a VFD which, in turn, is controlled by the microprocessor controller or by an external signal. Motor speed will be set on the VFD during the unit Test and Balance, but after that, the VFD will not normally be changed. Always check the motor amperage rating shown on the motor nameplate when changing the fan RPM. All access doors must be installed except the control center door.

Vibration

Vibration Causes

Off axis or loose components Drive component unbalance Poor inlet / outlet conditions Foundation stiffness

including structural and/or component failure. The most common sources of vibration are listed.

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.

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

Excessive vibration may be experienced during initial start-up. Left unchecked, excessive vibration can cause a multitude of problems,

Discharge Air Temperature Sensor

Units are supplied with a Discharge Air Temperature Sensor that is to be ﬁeld-installed prior to unit startup. The sensor is to be installed at least three duct diameters downstream of the heat exchanger. The sensor must be connected directly to the microprocessor controller. All other sensors and low voltage devices are to be connected to the low voltage terminal strip in the control center. The discharge air sensor is shipped loose and can be found in the unit’s control center. See the unit-speciﬁc wiring diagram for connection locations.

Typical Discharge Air

Temperature Sensor

Optional Hot Gas Bypass Valve

(standard scroll)

To adjust, 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 115 PSIG for R-410A (the valve will feel warm to the touch). Adjustments are made by ﬁrst removing the cap on the bottom of the valve and then turning the adjusting stem clockwise to increase the setting pressure (counterclockwise to decrease). Allow several minutes between adjustments for the system to stabilize. When adjustment is complete, replace the cap on the valve.

Packaged Rooftop Ventilator 25

Start-Up Components

Airﬂow Monitor

For additional information on how to navigate through the airﬂow controller menus, refer to technical manuals GF-2200A from GreenTrol® Automation Inc. at www.greentrol.com.

Field calibration procedure:

1. Turn off power to the unit using the power disconnect(s).

2. Remove the cover from the GreenTrol airﬂow monitoring controller.

3. Install a jumper wire between terminals R and G on the unit’s terminal board if one isn’t present.

4. When safe, turn the power back on to the unit using the power disconnect(s).

If no microprocessor controller, skip to step 8. Steps 5 thru 7 are for microprocessor only.

5. Look at the unit’s microprocessor controller screen and view the status of the unit. If the displayed status is “System Off” continue with step 6, otherwise go to step 7.

6. Adjust the unit on/off priorities on the unit’s microprocessor controller so that the unit will run for calibration.

a. Push the “Prg” button on the microprocessor

controller.

b. Use the up and down arrows to get to the “On/

Off Unit” menu.

c. Push the enter button to view the current unit

on/off priorities.

d. Push the down arrow to display the Unit ON/

OFF Control screen.

e. Record the settings below so they can be

changed back when calibration is complete.

By digit input: ___________

By BMS: ___________

By Scheduler: ___________

f. Use the enter button to navigate between the

different settings on the page, use the up and down arrows to change the values so that “By digit input” is the only setting with “Yes”.

7. Enter the service override menu to control the damper position.

a. At the Home Screen push the “Prg” button. (If

you’re not at the home screen push the escape button until you get there).

b. Use the up and down arrows to get to the

“Service” menu, then push the enter button.

c. If you’re asked for a password, enter “1000”

for the password and push enter.

d. Use the up and down arrows to get to the

“Overrides” screen, then push enter.

e. Use the arrow buttons to get the supply

override.

8. Measure the supply airﬂow rate of the unit using an approved test and balance method.

9. Without making any changes to the system, calibrate the airﬂow monitoring controller so it reads the airﬂow measured in step 8 by using the Field Calibration Wizard.

a. The ﬁeld calibration lasts for two minutes. Any

signiﬁcant changes in airﬂow will affect the accuracy of the reading.

b. To enter the Field Calibration Wizard, hold the

Down and Enter buttons simultaneously on the airﬂow controller, then release the buttons.

c. Push the enter button to go to Wizard 1.

d. Push the enter button twice and change Wiz1

Enable to YES.

e. When asked for the number of calibration

points (Cal Points), set the value to 1.

f. Push the enter button when the display says

“Set Flow 1”.

g. After completing the steps above, set the

FLOW1 value to the airﬂow measured in step 8, then push the enter button to begin calibration.

10. After the calibration is completed, measure the supply airﬂow rate again and compare with the value on the airﬂow controller’s display

a. If the values are within 5% of each other the

device has been successfully calibrated.

b. If the values are not within 5% of each other

repeat the ﬁeld calibration process.

11. If you had to change the On/Off priorities on the microprocessor unit controller, change them back to the values that were written down in part 6.

12. Turn off power to the unit using the power disconnect(s) and wait one minute for the variable frequency drive(s) to lose backup power.

13. Replace the cover to the GreenTrol airﬂow monitoring station.

14. If you added a jumper between terminals R and G in step 3 remove it at this time. If a jumper was already in place, leave it in place.

15. When safe, turn the power back on to the unit using the power disconnect(s).

a. Recycling of the power resets the manual

override values that were set during the calibration.

Packaged Rooftop Ventilator26

Troubleshooting – Alarms

Several of the electronic controls in the unit monitor the system for faults and will go into alarm, shutting down the unit or a single function within the unit.

Microprocessor Controller

Check the screen on the microprocessor for an alarm condition. If the microprocessor is in an alarm condition, a message will show on the microprocessor controller screen.

The microprocessor is located in the main control center. If the microprocessor is in alarm condition, the Alarm button will blink red. Press the Alarm button to see the speciﬁc condition or to reset the microprocessor. Refer to the microprocessor IOM for detailed information on fault codes and see the unitspeciﬁc wiring diagram.

Phase Monitor

The phase monitor has two LED indicator lights, one red and one green. Green indicates proper operational status, red indicates the unit has detected a fault and is in alarm condition. The alarm LED will blink to show the speciﬁc fault and there is a chart printed on the monitor that shows the code for the blinking light. The phase monitor is self-resetting once the alarm condition is corrected. It is located in the main control center.

Variable Frequency Drive (VFD)

Variable frequency drives have a display screen that will show an alarm condition. If a fault such as a voltage spike occurs, the VFD will go into alarm and will not reset until a hard restart is performed. See the unitspeciﬁc manufacturer’s manual supplied with the unit. VFDs are located in the main control center.

Optional Digital Scroll Compressor Controller

Present only if packaged DX with digital scroll option is selected. The controller has three LED indicator lights. One is green, indicating that it has power, one is an alarm indicator that will ﬂash a code for various alarm conditions and the third indicates whether the compressor is operating in a loaded or unloaded condition. See the manufacturer’s unit-speciﬁc manual for further information.

See the Fault Code chart below. The Fault Code chart is also printed on the back of the controller. Note that if the controller generates either a Code 2 or a Code 4 Lockout, a manual reset must be performed. Manual Reset is accomplished by shutting off main power to the unit and then turning it back on.

Digital Scroll Compressor

Controller Fault Codes

Alert Code

Code 2*

Code 3

Code 4* Locked Rotor Blinks 4 Times Lockout

Code 5

Code 6

Code 7 Future N/A N/A

Code 8

Code 9 Low Voltage Blinks 9 Times Trip Compressor

System Condition

High Discharge Temperature Trip

Compressor Protector Trip

Demand Signal Loss

Discharge Thermistor Fault

Welded Contactor

*Protective faults that require manual reset.

Diagnostic Alert Light

Blinks 2 Times Lockout

Blinks 3 Times Lockout

Blinks 5 Times Lockout

Blinks 6 Times

Blinks 8 Times

Action

Reduce Capacity

Unload Compressor

Packaged Rooftop Ventilator 27

Troubleshooting – Unit

Symptom Possible Cause Corrective Action

Blown fuse or open circuit breaker. Replace fuse or reset circuit breaker and check amps.

Blower fails to operate

Motor starters “chatter” or do not pull in

Motor over amps

Low airﬂow (cfm)

High airﬂow (cfm)

Excessive noise or vibration

Defective motor or capacitor. Replace.

Motor overloaded. Reset VFD and check amps.

Electrical.

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.

Static pressures are higher than design. Check for dirty ﬁlters. Improve ductwork.

Motor voltage incorrect.

Motor horsepower too low.

Shorted windings in motor. Replace motor.

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.

Leaks in ductwork. Repair.

Elbows or other obstructions may be obstructing fan outlet.

Blower fan speed too high.

Filter(s) not in place. Install ﬁlters.

Insufﬁcient static pressure (Ps). (airﬂow resistance)

Fan wheel rubbing on inlet.

Bearings.

Loose wheel on shaft. Tighten wheel hub.

Motor base or blower loose. Tighten mounting bolts.

Noise being transmitted by duct.

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

Shorten wiring run to mechanical room or install a relay to turn unit on/off. Consult factory for relay information. Increase wire gauge size so that resistance is 0.75 ohms or less.

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

Check motor wiring. Check motor nameplate versus supplied voltage.

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

Improve ductwork to eliminate losses using good duct practices.

Check maximum motor RPM and compare with catalog data. Verify that external control wiring is in place if required.

For 3-phase, see Direction of Fan Wheel Rotation Direction in Start-Up, Components section.

Replace ﬁlters or follow cleaning procedures in Routine Maintenance section of this manual.

Correct or improve ductwork.

Check for correct maximum fan RPM. Decrease maximum fan speed if necessary in the VFD.

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

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

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

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.

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

Packaged Rooftop Ventilator28

Troubleshooting – Refrigeration Circuit

TROUBLESHOOTING NOTE

IMPORTANT

Do not release refrigerant to the atmosphere! If 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.

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.

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

The ﬁrst step in troubleshooting a refrigeration circuit is to examine the microprocessor controller and digital scroll compressor controller (if present) and see if there is a fault code. The next step is to check airﬂow conditions (e.g. improper ductwork, atypical wet bulb / dry bulb, etc.). After these steps have been eliminated, proceed with troubleshooting by following this guide.

Symptom Possible Cause Corrective Action

Open disconnect switch or circuit breaker.

Compressor contactor not closing.

Blown fuse or tripped 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.

Compressor will not run or does not start

Compressor starts but cuts out on low pressure

Low pressure switch cuts out at 50 PSIG (PDX) or 25 PSIG (ASHP)

Low line voltage.

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

Motor thermal protector automatically resets. Allow time

Compressor motor protector open.

(2 hours) for compressor to cool down so protector will reset. Restart and check for reason overheat occurred.

Check motor for open circuit, short circuit, grounded

Compressor defective.

windings, or burn out. Compressor may be seized; check refrigerant. If necessary, replace compressor.

High pressure switch open or defective.

Low pressure switch open or defective.

Open room thermostat or control. (No cooling required).

If manual reset (high pressure), reset switch. (Switch opens at 610 psi and will not reset above 420 psi for R-410A). Replace if defective.

See switch label for setpoint.

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

Loose wiring. Check all wire terminals and tighten as necessary.

Low or loss of refrigerant charge.

Check refrigerant pressures and temperatures (subcooling.)

Check for dirty evaporator coil, dirty ﬁlters, dampers

Airﬂow restricted.

closed, iced evaporator coil, improper belt, check motor amps, check duct design.

Check refrigerant pressures, look for frosted tubing and

Restriction in refrigerant line.

components indicating a restriction. Check pressure drop across the ﬁlter drier.

Defective low pressure switch. Replace.

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

Packaged Rooftop Ventilator 29

Troubleshooting – Refrigeration Circuit

Symptom Possible Cause Corrective Action

Compressor starts but cuts out on high pressure switch

High pressure switch cuts out at 610 PSIG

Compressor cuts out on thermal overload

Refrigerant overcharge. Check pressures, charge by subcooling.

Condenser fan motor defective. Check fan motor.

Condenser coil inlet obstructed or dirty. Check coil and clearances. Clean coil if necessary.

Air or non-condensables in system.

Check high side equalized pressures, check expansion valves.

Defective high pressure switch. Replace.

Restriction in discharge or liquid line.

Check refrigerant line pressures, check expansion valves, replace any defective component.

Condensing fan relay not pulling in. Replace.

Low voltage. Check voltage.

Sustained high discharge pressure.

High suction and discharge pressures.

Defective compressor overload.

Check running amperage and conditions described under “low suction pressure” symptoms.

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

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

Improper refrigerant charge. Check subcooling.

Improperly wired. Review wiring schematics.

Compressor hums, but will not start

Compressor noisy or vibrating

Loose wiring. Check all connections.

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 relay. Replace relay.

Motor winding damaged. Verify amp draws. Replace compressor if necessary.

Internal compressor mechanical damage.

Replace.

Refrigerant overcharge. Check pressures and subcooling.

Liquid ﬂoodback.

Tubing rattle.

Scroll compressor rotating in reverse. (3-phase)

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 high and low side pressures during operation to conﬁrm. Rewire for opposite rotation.

Damaged compressor. Replace the compressor.

Improper mounting on unit base.

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

Packaged Rooftop Ventilator30

Check that compressor is properly isolated and mounting bolts are tight.

Troubleshooting – Refrigeration Circuit

Symptom Possible Cause Corrective Action

Low discharge pressure

Compressor short cycles

Compressor loses oil

Not enough capacity or lack of performance

Liquid line is frosted or wet

Suction line is frosting

Frost on evaporating coil (Note: Normal on ASHP units in heating mode).

Insufﬁcient refrigerant charge.

Defective or improperly adjusted expansion valve.

Low suction pressure. See “low suction pressure”.

Faulty condenser temperature controls. (Condensing fan cycle switch).

Thermostat location or controls malfunction.

Improper refrigerant charge. Check subcooling, verify superheat.

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

Poor air distribution. Check ductwork for recirculating.

Low airﬂow at evaporator coil. Check blower operation and airstream restrictions.

Incorrect unit selection (oversized). Contact factory.

Refrigerant leak. Check system for leaks. Repair leaks and add refrigerant.

Short cycling. Check low pressure control settings.

Refrigerant ﬂood back.

Reheat ﬂush cycle inadequate. Contact factory.

Refrigeration undercharged. Check subcooling. Adjust charge, if necessary.

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

Dirty or clogged condensing coil. Check coil and airﬂow.

Air or other non-condensables in system.

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.

Restriction in liquid line.

Insufﬁcient evaporating coil airﬂow.

Malfunctioning or defective expansion valve.

Hot gas bypass valve not functioning properly (if equipped).

Manual hot gas bypass valve closed (if equipped).

Low load or airﬂow. Increase airﬂow, check ﬁlters.

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

Check superheating and adjust thermal expansion valve.

Check condenser controls and reset to obtain desired condensing temperature.

Check thermostat, check heat anticipator setting.

Check thermal expansion valve setting. Check for refrigerant overcharge. Check crankcase heater operation.

Check equalized high side pressure with equivalent outdoor temperature.

Clear restriction upstream of point of frosting. (Note: liquid line frosting in normal on ASHP units).

Check airﬂow, check ﬁlters, check VFD control signal for proper operation.

Check bulb of thermal expansion valve.

Check valve. If defective, replace.

Open valve.

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

Packaged Rooftop Ventilator 31

Troubleshooting – Refrigeration Circuit

Symptom Possible Cause Corrective Action

Low discharge pressure

Compressor short cycles

Compressor loses oil

Not enough capacity or lack of performance

Liquid line is frosted or wet

Suction line is frosting

Frost on evaporating coil (Note: Normal on ASHP units in heating mode).

Insufﬁcient refrigerant charge.

Defective or improperly adjusted expansion valve.

Low suction pressure. See “low suction pressure”.

Faulty condenser temperature controls. (Condensing fan cycle switch).

Thermostat location or controls malfunction.

Improper refrigerant charge. Check subcooling, verify superheat.

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

Poor air distribution. Check ductwork for recirculating.

Low airﬂow at evaporator coil. Check blower operation and airstream restrictions.

Incorrect unit selection (oversized). Contact factory.

Refrigerant leak. Check system for leaks. Repair leaks and add refrigerant.

Short cycling. Check low pressure control settings.

Refrigerant ﬂood back.

Reheat ﬂush cycle inadequate. Contact factory.

Refrigeration undercharged. Check subcooling. Adjust charge, if necessary.

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

Dirty or clogged condensing coil. Check coil and airﬂow.

Air or other non-condensables in system.

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.

Restriction in liquid line.

Insufﬁcient evaporating coil airﬂow.

Malfunctioning or defective expansion valve.

Hot gas bypass valve not functioning properly (if equipped).

Manual hot gas bypass valve closed (if equipped).

Low load or airﬂow. Increase airﬂow, check ﬁlters.

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

Check superheating and adjust thermal expansion valve.

Check condenser controls and reset to obtain desired condensing temperature.

Check thermostat, check heat anticipator setting.

Check thermal expansion valve setting. Check for refrigerant overcharge. Check crankcase heater operation.

Check equalized high side pressure with equivalent outdoor temperature.

Clear restriction upstream of point of frosting. (Note: liquid line frosting in normal on ASHP units).

Check airﬂow, check ﬁlters, check VFD control signal for proper operation.

Check bulb of thermal expansion valve.

Check valve. If defective, replace.

Open valve.

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

Packaged Rooftop Ventilator32

Routine Maintenance

DANGER

Electric shock hazard. Can cause injury or death. Before attempting to perform any service or maintenance, turn the electrical power to the unit to OFF at disconnect switch(es). Unit may have multiple power supplies.

CAUTION

This unit requires minimal maintenance to operate properly. Maintenance requirements for this model vary for each installation and depend greatly on how much the system is used and the cleanliness of the air. Proper maintenance will both increase the life of the system and maintain its efﬁciency. Maintenance must be performed by experienced technicians and in the case of refrigeration systems, must be done by an EPA certiﬁed technician.

Maintenance frequency is based on a presumed nominal use of the system. If the system is being run constantly, the frequency should be adjusted accordingly. If there is seasonal debris in the air which can be drawn into the ﬁlters and the coils, they should be checked more frequently. If the system is being used for only a few hours per day, the frequency may be reduced. Use the maintenance log at the end of this manual to record each maintenance session and observations and then establish a maintenance schedule that is appropriate for the installation. The following is provided as a guideline.

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.

1. Lubrication Apply lubricant where required

2. Dampers Check for unobstructed operation

3. Blower Wheel and Fasteners Check for cleanliness

Check all fasteners for tightness Check for fatigue, corrosion, wear

4. Door Seal Check if intact and pliable

5. Wiring Connections Check all connections for tightness

6. Cabinet Check entire cabinet, inside and out, for dirt

buildup or corrosion. Remove accumulated dirt, remove any surface corrosion and coat the area with appropriate ﬁnish.

Maintenance Frequency:

Monthly

1. External Filter Clean metal mesh ﬁlters

2. Internal Filters Replace MERV 8 ﬁlters monthly.

Adjust replacement schedule for MERV 13 and MERV 14 or other ﬁlters as inspection requires.

Semiannually

1. Check motor and motor bearings Check for excessive heat, vibration or noise.

Lubricate bearings in accordance with the motor manufacturer’s recommendations.

2. Condensate Drain (if applicable) Inspect and clean – reﬁll with water

3. Heat Transfer Coils (if applicable) Inspect for cleanliness – clean as required

4. Outdoor Fan Blades and Motor (if applicable) Check for cleanliness

Check all fasteners for tightness Check for fatigue, corrosion, wear

Packaged Rooftop Ventilator 33

Maintenance Procedures:

Filter

Lubrication - Check all moving components for

proper lubrication. Apply lubricant 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.

Gas Furnace - Maintain furnace in accordance with

instructions in the Indirect Gas-Fired Heat IOM shipped with this unit.

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 cooling. Never wash-down the motor with high pressure spray. Greasing of motors is only intended when ﬁttings are provided. Fan motors typically have two grease ﬁttings. Each motor manufacturer has different lubrication schedules for different models. Go to the motor manufacturer’s website and download their maintenance requirements. Do not over-lubricate motors or use an incompatible grease. Many fractional motors are permanently lubricated for life and require no further lubrication.

Fan Wheel and 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.

Internal Filter Maintenance - The unit will typically be

provided with 2-inch thick pleated paper ﬁlters in the airstream. These ﬁlters should be checked according to a routine maintenance schedule and replaced as necessary to ensure proper airﬂow through the unit. Replacement ﬁlters shall be of same performance and quality as factory installed ﬁlters. Filter must be pleated design with integral metal grid. Two acceptable ﬁlter replacements are Aerostat Series400 or Farr 30/30®.

Filters upstream of the coil should be checked regularly. If the ﬁlters are dirty, they should be cleaned or replaced. It is important the ﬁlters stay clean to maintain desired airﬂow.

WARNING

REFER TO GENERAL SAFETY INFORMATION

Do not operate this unit without the ﬁlters and birdscreen 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.

External Filter Maintenance- Aluminum mesh, 2-inch

thick ﬁlters are located in the supply weatherhood (if the weatherhood option was purchased). These 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 by rinsing with a mild detergent in warm water prior to start-up.

Outdoor Air Intake Hood

Mesh Filter Access

Coil Maintenance- Coils must be cleaned to maintain

maximum performance. Check coils once per 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 a 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 use 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.

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.

Packaged Rooftop Ventilator34

Reference - Venting Connection Locations

COMBUSTION AIR INLET

EXHAUST OUTLET

200-300MBH

COMPRESSOR / CONTROL CENTER

ACCESS

COMBUSTION AIR INLET

IG FURNACE

ACCESS

EXHAUST OUTLET

500MBH

COMPRESSOR

ACCESS

CONTROL CENTER

ACCESS

IG FURNACE

ACCESS

COMPRESSOR

ACCESS

IG FURNACE

ACCESS

100-150MBH

COMPRESSOR / CONTROL CENTER

ACCESS

300-400MBH

CONTROL CENTER

ACCESS

IG FURNACE

ACCESS

COMBUSTION AIR INLET

EXHAUST OUTLET

Model

XRV-25

XRV-45

IG Venting Location

Flue Connection Size

Furnace

Size (MBH)

A B C D

Standard 2-Pipe/Concentric

(diameter in inches)

Exhaust Exhaust Intake 100 150 4 4 4

14 23.5 20.5 20.5

200 250 6 6 6

15.2 23.7 31.5 35.9

4 4 4

6 6 6

300 6 6 6 300 400 6 6 6

14.8 23.3 38.1 44.1

6 6 6

500 14.9 23.6 25.2 57.1 6 6 6

Packaged Rooftop Ventilator 35

Reference - Rated Airﬂow

Model Airflow (SCFM)

XRV-25-5I 2325

XRV-25-5D 2325

XRV-25-5S 2325

XRV-25-5A 3400

XRV-25-7.5I 2300

XRV-25-7.5D 2300

XRV-25-7.5S 2300

XRV-25-7.5A 3000

XRV-25-10I 2700

XRV-25-10D 2800

XRV-25-10S 2800

XRV-25-10A 4400

XRV-25-12.5I 3400

XRV-25-12.5D 3550

XRV-25-12.5S 3550

XRV-25-12.5A 4400

XRV-25-15I 3775

XRV-25-15D 3775

XRV-25-15S 3775

XRV-25-15A 4300

XRV-45-15I 4100

XRV-45-15D 4100

XRV-45-15S 4100

XRV-45-15A 4800

XRV-45-17.5I 4650

XRV-45-17.5D 4650

XRV-45-17.5S 4650

XRV-45-17.5A 5500

Model Airflow (SCFM)

XRV-45-20I 4900

XRV-45-20D 5100

XRV-45-20S 5100

XRV-45-20A 6400

XRV-45-25I 5750

XRV-45-25D 5600

XRV-45-25S 5600

XRV-45-25A 7200

XRV-45-30I 6000

XRV-45-30D 6000

XRV-45-30S 5750

XRV-45-30A 7000

XRV-70-25D 6500

XRV-70-25S 6500

XRV-70-30D 7000

XRV-70-30S 7000

XRV-70-35D 7000

XRV-70-35S 7000

XRV-70-43D 8100

XRV-70-43S 8100

Packaged Rooftop Ventilator36