AAON®
RM SERIES
HEATING • COOLING & COMBINATION ROOFTOP UNITS
USERS
INFORMATION
MANUAL
▲! WARNING
If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life.
FOR YOUR SAFETY
DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE.
7-2003
FOR YOUR SAFETY
WHAT TO DO IF YOU SMELL GAS
•EXTINGUISH ANY OPEN FLAME.
•DO NOT TOUCH ANY ELECTRICAL SWITCH.
•DO NOT TRY TO LIGHT ANY APPLIANCE.
•DO NOT USE ANY PHONE IN YOUR BUILDING.
•IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR'S PHONE.
FOLLOW THE GAS SUPPLIER'S INSTRUCTIONS.
•IF YOU CANNOT REACH YOUR GAS SUPPLIER, CALL THE FIRE DEPARTMENT.
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AAON®
TABLE OF CONTENTS
SECTION |
PAGE NUMBER |
OWNER'S INFORMATION ………………………………………………………………………………3 - 4
HEATING / COOLING SYSTEMS …………………………………………………………………… 4 - 5
Gas Unit Lighting Instructions
PERIODIC INSPECTION PROCEDURES…………………………………………………………… 6 - 7
SERVICE, TROUBLE SHOOTING & MAINTENANCE …………………………………………… 8
Lubrication
Cleaning
FILTER INSTALLATION / REPLACEMENT ……………………………………………………… 9
SERVICING …………………………………………………………………………………………… 10 - 12
Rooftop Unit Replacement Parts
SEQUENCE OF OPERATIONS ……………………………………………………………………… 13 Heating
Cooling
Optional Economizer
VAV Systems …………………………………………………………………………………… 14 Power Exhaust Options
▲! IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFC's and HCFC's) as of July 1, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for non-compliance.
▲! WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a qualified installer, service agency
or the gas supplier.
Owner should pay particular attention to the words: NOTE, CAUTION AND WARNING.
NOTES are intended to clarify or make the installation easier. CAUTIONS are given to prevent equipment damage. WARNINGS are given to alert owner that personal injury and/or equipment damage may result if installation procedure is not handled properly.
It is the intent of AAON, Inc. to provide accurate and current specification information. However, in the interest of product improvement, AAON, Inc. reserves the right to change pricing, specifications and/or design of it's products without notice, obligation or liablity.
© 2003 AAON, Inc., all rights reserved throughout the world.
AAON & AAONAIRE are registered trademarks of AAON, Inc., Tulsa, OK.
R15700 (7-03)
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The units are designed as self-contained heating, cooling or combination units for outdoor installation only, using the refrigerant shown on the rating plate, chilled water, natural or propane gas, electric resistance, steam or hot water heating.
WARNING
Failure to observe the following instructions will result in premature failure of your system, and possible voiding of the warranty.
DIRECT EXPANSION (DX) COOLING UNITS
Never cut off the main power supply to the unit, except for complete shutdown. When power is cut off from the unit, compressors with crankcase heaters cannot prevent refrigerant migration. The compressor will cool down, and liquid refrigerant will accumulate in the compressor. The compressor is designed to pump only refrigerant gas and damage may occur when power is restored.
If power must be cut off for more than an hour, turn the thermostat system switch to "OFF", and leave it off until the main power switch has been turned on again for at least twenty four hours on units with compressor crankcase heaters. This will give the crankcase heater time to clear liquid accumulation out of the compressor before it is required to run.
Always control the system from the thermostat, or control panel, never at the main power supply (except in an emergency or complete shutdown of the system).
During the cooling season, if the air flow is reduced due to dirty air filters or other reasons, the cooling coils will get too cold and result in excessive liquid return to the compressor. As the liquid concentration accumulates, oil is washed out of the compressor, leaving it starved for lubrication.
The compressors must be on a minimum of 4 minutes and off for a minimum of 5 minutes. The cycle rate must not exceed 8 starts per hour.
THE COMPRESSOR LIFE WILL BE SERIOUSLY SHORTENED BY RESULTING REDUCED LUBRICATION, AND THE PUMPING OF EXCESS AMOUNTS
OF LIQUID OIL AND REFRIGERANT.
GAS OR ELECTRIC HEATING
The system is designed to heat a given amount of air each minute it operates. If the amount of air heated is greatly reduced (approximately 1/3 capacity), the heat exchanger / heater coil temperature will increase above acceptable level and result in shut down by a high temperature safety switch incorporated either in the heat exchanger or the heater area.
GAS HEAT UNITS - WARNING: If, due to safety switch shut off or gas supply shut off failure; ALWAYS CLOSE MANUAL GAS VALVE TO UNIT PRIOR TO ANY ELECTRICAL SERVICE.
PROLONGED OVERHEATING OF THE HEAT EXCHANGER WILL SHORTEN ITS LIFE.
OWNER'S INFORMATION
▲! WARNING
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.
AIRFLOW IS TO BE ADJUSTED AFTER INSTALLATION TO OBTAIN AN AIR TEMPERATURE RISE WITHIN THE RANGE SPECIFIED ON THE RATING PLATE.
DUE TO JOB SPECIFICATION REVISIONS, IT MAY BE NECESSARY TO ADJUST OR CHANGE THE SHEAVE OR PULLEY TO OBTAIN THE DESIRED AIRFLOW
AT THE TIME OF INSTALLATION.
▲! CAUTION
START-UP TECHNICIAN MUST CHECK BLOWER MOTOR AMPERAGE TO ENSURE THAT THE AMPERAGE LISTED ON THE MOTOR NAMEPLATE IS NOT EXCEEDED.
CAUTION: While the following incorrect operations may not cause damage to the system, they will impair the performance, and may cause the built-in safety devices to cut the system off completely.
1.LOW AMBIENT OPERATION
The cooling section of a direct expansion (DX) unit
will not operate properly when the outdoor temperature is below 55°F. Outside air intake options are necessary if operation below 55°F is expected.
2.MULTIPLE UNIT OPERATION
When several units are used in conditioning the space, and any are combination heating-cooling units, all system thermostat switches must be set at either heating, cooling, or set at "off". Do not run part of a system switched to an opposite mode. Cooling only units should be switched to "off" at the thermostat during the heating season.
WIRING DIAGRAMS
A complete set of unit specific wiring diagrams in both ladder and point-to-point form are laminated in plastic and located inside the control compartment door.
CONDENSATE PIPING
A drain trap is to be connected to the drainpan. If codes require a condensate drain line, it should be the same pipe size as the drain nipple and should pitch downward toward drain.
The condensate drain pipe ("P" trap) is factory supplied and shipped in the control access compartment for field installation. An air break should be used with long runs of condensate lines.
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OWNERS INFORMATION continued
!WARNING
Those sensitive to odors or gases from trace amounts of residual oils should NOT be present in the conditioned space during the start-up of a gas-fired installation.
IMPORTANT NOTICE:
All gas-fired heat exchangers are completely tested at the factory before shipment. This will remove nearly all of the oils that have been used in the manufacturing process, however, trace amounts may remain. When performing the initial start-up at the jobsite, it is highly recommended that people or any other living animals, that may be sensitive to the residual odors or gases, NOT be present in the conditioned space during the start-up. In all cases, including the initial factory firing and testing, any of the gases will be under the acceptable level of concentration for human occupancy.
NOTE: In case emergency shut down is required, turn off the main manual gas shut-off valve and disconnect main electrical power to unit. These devices should be properly labeled by the installer.
HEATING & COOLING SYSTEMS
NORMAL OPERATION
HEATING
Set the thermostat system switch to "HEAT".
Set the thermostat fan switch to "AUTO" or "ON". Set the thermostat temperature at the desired point.
COOLING
Set the thermostat system switch to "COOL".
Set the thermostat fan switch to "AUTO" or "ON". Set the thermostat temperature at the desired point.
AIR CIRCULATION
Set the thermostat system switch to "OFF". Set the thermostat fan switch to "ON".
Do not change temperature setting.
With these settings, the air circulating blower will run continuously but the air will not be heated or cooled.
SYSTEM OFF
Set the thermostat system switch to "OFF".
Set the thermostat fan switch to "AUTO". Do not change temperature setting.
With these settings, the system is shut down, with the exception of the control system power (24 Vac), and the crankcase heater of the compressor (approx. 60W).
DO NOT TURN OFF THE MAIN POWER SWITCH.
NIGHT AND VACANT WEEKEND OPERATION
To reduce the operation time during low load periods, it is recommended that the temperature setting be increased five degrees during these periods of the cooling season, and decreased ten degrees during the heating season.
GAS HEATING SYSTEM
The heating section is for use with natural gas supply pressure of 6" to 10.5" Water Column. The unit may also utilize propane gas with a supply pressure to the valve of 11" to 12" Water Column. The rating plate on the furnace must be inspected to make sure the unit is stamped for proper gas. A 1/8" pressure tap should be field supplied by the installer in the piping just ahead of the gas valve. The pressure tap on the outlet end of the gas valve can be checked to verify manifold pressure of 3.2" to 3.5" for natural gas.
Combustion air is supplied by a centrifugal blower which draws in outside air through a protected opening. This induced draft blower introduces the air to the burner tubes which assures even primary and secondary air flow.
All heating system and related safety controls are 100% tested on each unit prior to shipment.
The units are equipped with a direct spark ignition system which proves the burner operation during each call for heat. Power to the ignition control is 24 Vac to reduce hazards. Burner ignition is by a high intensity spark.
When heat is called for, the cooling system is inoperable except for the indoor blower motor. Heating is accomplished by firing gas into the heat exchanger assembly.
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GAS UNIT LIGHTING INSTRUCTIONS
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
A.This appliance does not have a pilot. It is equipped with an ignition device which automatically lights the burner.
Do not try to light the pilot by hand.
B.BEFORE OPERATING smell all around the appliance area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
•Do not try to light any appliance.
•Do not touch any electric switch; do not use any phone in your building.
•Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
•If you cannot reach your gas supplier, call the fire department.
C.Use only your hand to push in or turn the gas control knob. Never use tools. If the knob will not push in or turn by hand, don't try to repair it, call a qualified service technician. Force or attempted repair may result in a fire or explosion.
D.Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water.
OPERATING INSTRUCTIONS
1.STOP! Read the safety information above this label.
2.Set the thermostat to lowest setting.
3.Turn off all electric power to the appliance.
4.This appliance is equipped with an ignition device which automatically lights the burner. Do not try to light the pilot by hand.
GAS CONTROL KNOB SHOWN IN "ON" POSITION
GAS INLET
ON |
OFF |
5.Open control access panel.
6. |
Push in gas control knob slightly and turn clockwise |
to "OFF". |
NOTE: Knob cannot be turned to "OFF" unless knob is pushed in slightly. Do not force.
7.WAIT five (5) minutes to clear out any gas. Then smell for gas, including near the floor. If you smell gas, STOP! Follow "B" in the safety information above on this label. If you don't smell gas, go to the next step.
8. |
Turn gas control knob counterclockwise |
to "ON". |
9.Close control access panel.
10.Turn on all electric power to the appliance.
11.Set thermostat to desired setting.
12.If the appliance will not operate, follow the instructions "To Turn Off Gas To Appliance" and call your service technician or gas supplier.
TO TURN OFF GAS TO APPLIANCE
1.Set the thermostat to lowest setting.
2.Turn off all electric power to the appliance if service is to be performed.
3.Open control access panel.
4. |
Push in gas control knob slightly and turn clockwise |
to |
|
"OFF". Do not force. |
|
5.Close control access panel.
ELECTRIC HEATING SYSTEM
Heating is accomplished by passing electrical current through a specified amount of resistance heaters which produce the required heat. The indoor blower motor energizes at the same time as the heaters.
STEAM OR HOT WATER HEATING SYSTEM Heating is accomplished by passing steam or hot water through the steam or hot water coil assembly.
COOLING SECTION • DX
All direct expansion refrigeration systems are factory assembled, charged with refrigerant, tested and operated. On all units 8 ton and larger the refrigerant system includes multiple circuit evaporator and condenser coils providing two or more stages of cooling. These systems are provided with liquid line filter driers, expansion valves and fully hermetic compressors.
Compressors are equipped with a positive pressure forced lubrication system.
The air cooled condenser coil(s) are constructed of copper tubes and mechanically bonded aluminum fins and air pulled through by propeller fans. The evaporator coil is draw through type constructed of copper tubes and mechanically bonded aluminum fins.
The refrigeration section of these appliances has been found acceptable with applicable provisions of "ANSI / UL 1995" and current "C.S.A. Standard C22.2" by E.T.L.
NOTE: Crankcase Heater Operation
Some units are equipped with a compressor crankcase heater, which should be energized at least 24 hours prior to setting the thermostat for cooling operation.
COOLING SECTION • CHILLED WATER or NON-COMPRESSORIZED UNIT
Chilled water or non-compressorized units have factory installed coils. Systems are provided with internal header connections for field piping. Coils are constructed of copper tubes and mechanically bonded aluminum fins.
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