STELLAR 2000 SINGLE PACKAGE AIR CONDITIONERS GAS/ELECTRIC, AIR-COOLED INSTALLATION INSTRUCTION

Transcription

1 STELLAR 2000 SINGLE PACKAGE AIR CONDITIONERS GAS/ELECTRIC, AIR-COOLED INSTALLATION INSTRUCTION Supersedes: N4Y (893) N4Y (1294) MODELS D3GA018 THRU 042 (10 SEER) GENERAL YORK Model D3GA units are cooling/heating air conditioners designed for outdoor installation. Only gas piping, electric power and duct connections are required at the point of installation. The gas-fired heaters have hot surface ignition. The tubular heat exchangers are aluminized steel. This appliance is not to be used for temporary heating of buildings or structures under construction. INSPECTION As soon as a unit is received, it should be inspected for possible damage during transit. If damage is evident, the extent of the damage should be noted on the carrier s freight bill. A separate request for inspection by the carrier s agent should be made in writing. Refer to Form NM for additional information. RENEWAL PARTS Refer to Renewal Parts, Form RP1Y for Key Replacement Parts. 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. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance. Extinguish any open flames. Do not touch any electrical 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. Installation and service must be performed by a qualified installer, service agency or the gas supplier. All forms referenced in this instruction may be ordered from: Publications Distribution Center Unitary Products Group P.O. Box 1592, York, Pa APPROVALS Design certified by CGA and UL listed as follows: 1. For use as a forced air furnace with cooling unit. 2. For outdoor installation only. 3. For installation directly on combustible flooring or, in the U.S.A., on wood flooring or Class A, B, or C roof covering material. 4. For use with natural gas and/or propane (LP) gas. Not suitable for use with conventional venting systems. CAUTION THIS PRODUCT MUST BE INSTALLED IN STRICT COMPLIANCE W ITH THE ENCLOSED INSTALLATION INSTRUCTIONS AND ANY APPLICABLE LOCAL, STATE, AND NATIONAL CODES INCLUDING, BUT NOT LIMITED TO, BUILDING, ELECTRICAL, AND MECHANICAL CODES. WARNING INCORRECT INSTALLATION MAY CREATE A CONDITION WHERE THE OPERATION OF THE PRODUCT COULD CAUSE PERSONAL INJURY OR PROPERTY DAMAGE. Installer should pay particular attention to the words: NOTE, CAUTION and WARNING. Notes are intended to clarify or make the installation easier. Cautions are given to prevent equipment damage. Warnings are given to alert installer that personal injury and/or equipment damage may result if installation procedure is not handled properly.

2 N4Y General... 1 Inspection... 1 Renewal Parts... 1 Approvals... 1 Nomenclature... 2 TABLE OF CONTENTS Hot Surface Ignitor Instructions Remote Sensor Instructions Adjustment of Temperature Rise Checking Gas Input Secure Owner s Approval INSTALLATION Limitations... 3 Location... 3 Rigging and Handling... 3 Clearances... 3 Ductwork... 3 Filters... 4 Condensate Drain... 4 Service Access... 4 Thermostat... 4 Power and Control Wiring... 4 Compressors... 5 Combustion Discharge... 5 Gas Piping... 5 Gas Connection... 5 Low NOx Application... 6 Flue Vent Hoods... 6 SEQUENCE OF OPERATION Heating... 8 Cooling... 8 START-UP Pre-start Check List... 8 Operating Instructions... 9 To Turn Off Gas To Unit... 9 Post-Start Check List... 9 Manifold Gas Pressure Adjustment... 9 Burner Instructions... 9 MAINTENANCE Normal Maintenance Cleaning Flue Passages and Heating Elements TABLES No. Description Page 1 Units Application Data Natural Gas Application Data LP Gas Application Data Natural Gas Pipe Sizing LP Gas Pipe Sizing Physical Data Electrical Data Gas Rate - Cubic Feet Per Hour FIGURES No. Description Page 1 Center of Gravity Field Wiring Diagram External Supply Connection Flue Vent Hood Dimensions and Clearances Gas Valves... 9 NOMENCLATURE D 3 G A N PRODUCT CATEGORY D = Single Package Air Conditioner PRODUCT GENERATION 3 = 3rd Generation PRODUCT IDENTIFIER GA = Gas / Electric NOMINAL COOLING CAPACITY 018 = Ton 024 = 2 Ton 030 = Ton 036 = 3 Ton 042 = Ton FACTORY INSTALLED GAS HEAT N = Natural Gas Heat Installed VOLTAGE CODE 06 = 208/ NOMINAL GAS HEATING OUTPUT CAPACITY 028 = 28 MBH 042 = 42 MBH 060 = 60 MBH 070 = 70 MBH 2 Unitary Products Group

3 LIMITATIONS These units must be installed in accordance with the following national and local safety codes. 1. National Electrical Code ANSI/NFPS No. 70 or Canadian Electrical Code Part 1, C22.1 (latest editions). 2. National Fuel Gas Code Z223.1 or CAN/CGA B149.1 or.2 Installation Code. 3. Local gas utility requirements. 4. Local plumbing and waste water codes and other applicable local codes. Refer to Table 1 for unit application data and to Table 2 for gas heat application data. INSTALLATION N4Y RIGGING OR HANDLING Care must be exercised when moving the unit. Do not remove any packaging until the unit is near the place of installation. Rig unit with slings placed under the unit. Spreader bars of sufficient length should be used across the top of the unit. BEFORE LIFTING A UNIT, MAKE SURE THAT ITS WEIGHT IS DISTRIBUTED EQUALLY ON THE CABLES SO THAT IT WILL LIFT EVENLY. Units may also be moved or lifted with a fork-lift. Slotted openings in the skid are provided for this purpose. Refer to Table 4 for unit weights and to Figure 1 for approximate center of gravity. If components are to be added to a unit to meet local codes, they are to be installed at the dealer s and/or the customer s expense. Size of unit for proposed installation should be based on heat loss calculations made according to methods of the Air Conditioning Contractors of America. TABLE 1 - UNIT APPLICATION DATA Model D3GA Voltage Variation Min./Max /253 Wet Bulb Temp. ( F) of Air on Evap. 57/72 57/72 57/72 57/72 57/72 Cooling Coil, Min./Max. Dry Bulb Temp. ( F) of Air on Cond. 45/120 45/120 45/120 45/120 45/120 Coil, Min./Max. Heating Minimum Ambient Temperature. ( F) Utilization range A in accordance with ARI Standard 110. LOCATION Use the following guidelines to select a suitable location for these units. 1. Unit is designed for outdoor installation only. 2. Condenser must have an unlimited supply of air. Where a choice of location is possible, position unit on either north or east side of building. WARNING:Excessive exposure of this furnace to contaminated combustion air may result equipment damage or personal injury. Typical contaminates include: permanent wave solutions, chlorinated waxes and cleaners, chlorine based swimming pool chemicals, water softening chemicals, carbon tetrachloride, Halogen type refrigerants, cleaning solvents (e.g. perchloroethylene), printing inks, paint removers, varnishes, hydrochloric acid, cements and glues, antistatic fabric softeners for clothes dryers, masonry acid washing materials. 3. For ground level installation, use a level concrete slab with a minimum thickness of 4 inches. The length and width should be at least 6 inches greater than the unit base. Do not tie the slab to the building foundation. 4. For roof top installation, be sure the structure will support the weight of the unit plus any field installed components. Unit must be installed on a level roof curb or appropriate angle iron frame providing adequate support under the compressor/condenser section. 5. Maintain level tolerance of unit to 1/8" maximum. APPROXIMATE CENTER OF GRAVITY 30-1/2 15-1/8 FIG. 1 - CENTER OF GRAVITY 67-3/4 FRONT CLEARANCES All units require certain clearances for proper operation and service. Installer must make provisions for adequate combustion and ventilation air in accordance with Section 5.3, Air for Combustion and Ventilation of the National Fuel Gas Code, ANSI Z223.1 (in U.S.A.) or Sections 7.2, 7.3 or 7.4 of Gas Installation Codes CAN/CGA-B149.1 and.2 (in Canada) and/or applicable provisions of the local building codes. Refer to Figure 5 for the clearances required for combustible construction, servicing, and proper unit operation. WARNING:Do not permit overhanging structures or shrubs to obstruct the condenser air discharge, combustion air inlet or vent outlet. DUCT WORK Duct work should be designed and sized according to the methods of the Air Conditioning Contractors of America (ACCA), as set forth in their Manual K. A closed return duct system shall be used. This shall not preclude use of economizers or ventilation air intake. Flexible joints may be used in the supply and return duct work to minimize the transmission of noise. CAUTION: When fastening duct work to the side duct flanges on the unit, insert the screws through the duct flanges only. DO NOT insert the screws through the casing. Outdoor duct work must be insulated and waterproofed. NOTE: Be sure to note supply and return openings. Refer to Figure 5 for information concerning side supply and return air duct openings. 30 Unitary Products Group 3

4 N4Y FILTERS A high velocity filter must be field supplied. Filters must always be used ahead of evaporator coil and must be kept clean or replaced with same size and type. Dirty filters will reduce the capacity of the unit and will result in frosted coils or safety shutdown. CONDENSATE DRAIN The draw-thru indoor coil requires a condensate trap. The plumbing must conform to local codes. Use a sealing compound on male pipe threads. Install the condensate drain line ( 3 4 NPTF) to spill into an open drain. SERVICE ACCESS Access to all serviceable components is provided by the following removable panels: Service access compartment Blower compartment Gas control service access Refer to Figure 5 for location of these access panels. THERMOSTAT The room thermostat should be located on an inside wall approximately 56" above the floor where it will not be subject to drafts, sun exposure or heat from electrical fixtures or appliances. Follow manufacturer s instructions enclosed with the thermostat for general installation procedure. Four color coded insulated wires (#18 AWG) should be used to connect thermostat to unit. See Figure 2. POWER AND CONTROL WIRING Field wiring to the unit must conform to provisions of the current N.E.C. ANSI/NFPA No. 70 or C.E.C. and/or local ordinances. The unit must be electrically grounded in accordance with local codes or, in their absence, with the N.E.C./C.E.C. Voltage tolerances which must be maintained at the compressor terminals during starting and running conditions are indicated on the unit Rating Plate and Table 7. The wiring entering the cabinet must be provided with mechanical strain relief. A fused disconnect switch should be field provided for the unit. Refer to Figure 5 for installation location. If any of the wire supplied with the unit must be replaced, replacement wire must be of the type shown on the wiring diagram. Electrical line must be sized properly to carry the load. Each unit must be wired with a separate branch circuit fed directly from the meter panel and properly fused. Refer to Figure 2 for typical field wiring and to the appropriate unit wiring diagram for control circuit and power wiring information. CAUTION: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing. * EITHER OF THE FOLLOWING MAY BE USED THERMOSTAT 2TH (OR) PROGRAMMABLE THERMOSTAT 2ET THERMOSTAT* CONTROL WIRING UNIT TERMINAL STRIP NOTE: HEAT ANTICIPATOR SHOULD BE SET AT 0.65 AMPS FOR ALL MODELS. 24 VOLT TRANSFORMER POWER WIRING TERMINAL IN CONTROL BOX UNIT CABINET GROUND LUG FIELD-SUPPLIED FUSED DISCONNECT STRAIN RELIEF REQUIRED SINGLE PHASE POWER SUPPLY FIG. 2 - TYPICAL FIELD WIRING DIAGRAM 4 Unitary Products Group

5 COMPRESSORS On some units the compressor is mounted on springs which have been tightened down for shipment only. After this unit is installed, back out the compressor bolts until the sleeve clears the top grommet. CAUTION: Do Not loosen compressor mounting bolts. COMBUSTION DISCHARGE The products of combustion are discharged horizontally through a screened (hooded) opening on the gas heat access panel. TABLE 2 - NATURAL GAS APPLICATION DATA Input Capacity (Mbh) Output Capacity (Mbh) Available On Models Gas Rate 1 Ft. 3 /Hr. Temp. Rise F At Full Input 2 Min. Max & 2 TON TON TON TON TON TON TON &3 1 2 TON Based on 1075 BTU/Ft The air flow must be adjusted to obtain a temperature rise within the range shown. TABLE 3 - PROPANE (LP) GAS APPLICATION DATA Input Capacity (Mbh) Output Capacity (Mbh) Available On Models Gas Rate 1 Ft. 3 /Hr. Temp. Rise F At Full Input 2 Min. Max & 2 TON TON TON TON TON TON TON &3 1 2 TON Based on 2500 BTU/Ft The air flow must be adjusted to obtain a temperature rise within the range shown. GAS PIPING Proper sizing of gas piping depends on the cubic feet per hour of gas flow required, specific gravity of the gas and the length TABLE 4 - NATURAL GAS PIPE SIZING CHART Length Nominal Inches Iron Pipe Size in Feet 1/2 in. 3/4 in. 1 in. 1-1/4 in , Maximum Capacity of Pipe in Cubic Feet of Gas Per Hour (Based Upon A Pressure Drop of 0.3 Inch Water Column and 0.6 Specific Gravity Gas). of run. National Fuel Gas Code Z223.1 or CAN/CGA B149.1 or.2 should be followed in all cases unless superseded by local codes or gas company requirements. Refer to Tables 4 and 5. The heating value of the gas may differ with locality. The value should be checked with the local gas utility. NOTE: There may be a local gas utility requirement specifying a minimum diameter for gas piping. All units require a 1/2 inch pipe connection at the gas valve. TABLE 5 - PROPANE (LP) GAS PIPE SIZING CHART Length Nominal Inches Iron Pipe Size in Feet 1/2 in. 3/4 in. 1 in. 1-1/4 in ,071 2, , , , Maximum Capacity of Pipe in Thousands of BTU Per Hour (Based Upon A Pressure Drop of 0.5 Inch Water Column). GAS CONNECTION The gas supply line can be routed through the hole located on the right side of the unit. Refer to Figure 5 to locate these access openings. Typical supply piping arrangements are shown in Figure 3. AUTOMATIC GAS VALVE FIG. 3 - EXTERNAL SUPPLY CONNECTION EXTERNAL SHUT-OFF Gas piping recommendations: N4Y NPT 1. A drip leg and a ground joint union must be installed in the gas piping. 2. When required by local codes, a manual shut-off valve may have to be installed outside of the unit. 3. Use wrought iron or steel pipe for all gas lines. Pipe dope should be applied sparingly to male threads only. WARNING:Natural gas may contain some propane. Propane, being an excellent solvent, will quickly dissolve white lead or most standard commercial compounds. Therefore, a special pipe dope must be applied when wrought iron or steel pipe is used. Shellac base compounds such as Gaskolac or Stalastic, and compounds such as Rectorseal #5, Clyde s or John Crane may be used. Unitary Products Group 5

6 N4Y 4. All piping should be cleaned of dirt and scale by hammering on the outside of the pipe and blowing out the loose dirt and scale. Before initial start-up, be sure that all of the gas lines external to the unit have been purged of air. 5. The gas supply should be a separate line and installed in accordance with all safety codes as prescribed under Limitations. After the gas connections have been completed, open the main shut-off valve admitting normal gas pressure to the mains. Check all joints for leaks with soap solution or other material suitable for the purpose. NEVER USE A FLAME. 6. The furnace and its individual manual shut-off valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of 1/2 psig (3.48 kpa). The furnace must be isolated from the gas supply piping system by closing its individual manual shut-off valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.48kPa). FLUE VENT HOOD The flue vent hood with screen is not shipped attached. This hood must be installed to assure proper unit operation. The hood must be fastened to the outside of the gas heat access panel with the screws provided in the bag attached to the inside of the combustion compartment. The flue vent hood is installed by inserting the top flange of the hood into the slotted opening in the access panel, positioning the vent screen between the hood flanges and the access panel, and securing in place using 2 screws. GAS HEAT ACCESS PANEL VENT OUTLET AIR HOOD VENT OUTLET SCREEN FIG. 4 - FLUE VENT HOOD TABLE 6 - PHYSICAL DATA MODELS D3GA EVAPORATOR CENTRIFUGAL BLOWER (Dia. x Wd. in.) 9 x 6 10 x 8 10 x 8 10 x x 10 BLOWER FAN MOTOR HP (THREE SPEED) ROWS DEEP EVAPORATOR FINS PER INCH COIL FACE AREA (Sq. Ft.) PROPELLER DIA. (in.) CONDENSER FAN MOTOR HP FAN NOM. CFM TOTAL 1,800 1,800 2,200 2,400 2,600 ROWS DEEP CONDENSER FINS PER INCH COIL FACE AREA (Sq. Ft.) CHARGE REFRIGERANT 22 (lbs./oz.) 5/6 4/4 5/0 5/4 5/2 UNIT WEIGHT lbs TABLE 7 - ELECTRICAL DATA MODEL D3GA POWER SUPPLY VOLTAGE LIMITATIONS (SEE NOTE 1) COMPRESSOR MIN. MAX. RLA LRA COND. FAN MOTOR, FLA SUPPLY AIR BLOWER MOTOR, FLA TOTAL UNIT AMPACITY, AMPS MAX. FUSE SIZE, (SEE NOTE 2) MAX. HACR BREAKER SIZE, AMPS MIN. WIRE SIZE, AWG (SEE NOTE 3) AMPS / / / / / NOTES: 1. Utilization Range A in accordance with ARI Standard Dual element, time delay type. 3. Based on 75 C copper conductors. 6 Unitary Products Group

7 N4Y All dimensions are in inches. They are subject to change without notice. Certified dimensions will be provided upon request. CONDENSER COIL GAS SUPPLY DIA. HOLE 22 CONDENSATE 17 DRAIN 3 4 NPTF EVAPORATOR COIL (RETURN AIR OPENING) REAR VIEW SUPPLY AIR OPENING BLOWER SERVICE ACCESS COMPARTMENT PANEL VENT AIR OUTLET HOOD CONDENSER COIL 29 (OVERALL) COMBUSTION AIR INLET LOUVERS GAS CONTROL SERVICE ACCESS COMPARTMENT PANEL (OVERALL) HIGH VOLTAGE CONN. 7 8 DIA. KNOCKOUT LOW VOLTAGE CONN. 7 8 DIA. KNOCKOUT (OVERALL) 9 FRONT VIEW ELECTRICAL SERVICE ACCESS COMPARTMENT PANEL CLEARANCES Front 36" Back 6" Left Side (Filter Access) 24" Right Side 24" Below Unit 1 0" Above Unit 2 48"3 (For Condenser Air Discharge 1 Units may be installed on combustible floors made from wood or class A, B or C roof covering material. 2 Units must be installed outdoors. Overhanging structures or shrubs should not obstruct condenser air discharge outlet. 3 32" maximum horizontal extension overhang. NOTE: A 1" clearance must be provided between any combustible material and the supply air ductwork. The products of combustion must not be allowed to accumulate within a confined space and recirculate. FIG. 5 - DIMENSIONS AND CLEARANCES Unitary Products Group 7

8 N4Y The unit is controlled by a conventional four wire heating/cooling thermostat common to this class of equipment. HEATING On a call to heat, the room thermostat contacts close signaling the control module. After the thermostat activation period of 3 seconds, the microprocessor runs its self-check routine verifying normal condition of all inputs/outputs (I/O). The control module energizes the flue inducer motor and enters into pre-purge period of 15 seconds. Following the pre-purge period the igniter is energized and the igniter warm-up period begins. In the igniter warm-up period the igniter is activated for 3 seconds, and remains energized for 7 seconds. After completion of the warm-up time, flame failure response time of more than 0.5 seconds and less than or equal to 0.8 seconds is changed and set at 2.0 seconds, the gas valve is energized and the trial for ignition period begins. During the trial for ignition period, the gas valve is activated for 3 seconds after the igniter activation and remains open for 5 seconds. The gas valve is de-energized (if the flame is not sensed). If there is a malfunction, the diagnostic LED will flash an error until the number of flashes are over. It then waits for 2 seconds until starting the flash sequence over. The indicator shall provide the following flash codes: (A) OFF - Normal operation. (B) ON - Board failure. (C) 1 flash - Ignition attempts or recycles. (D) 2 flashes - Compressor low pressure switch open. (E) 3 flashes - Compressor high pressure switch open. (F) 4 flashes - Flue inducer centrifugal switch open (fault) or closed (fault). (G) 5 flashes - Flame rollout switch open. (H) 6 flashes - Furnace high limit switch open. (I) 7 flashes - (optional) - Heating mode 1 hour waiting period for auto reset from flame failure lockout. SEQUENCE OF OPERATION NOTE: If the flame is neither sensed nor established (at first attempt), the control will attempt 11 more trials before entering into a lockout. If the flame is sensed, the blower on delay period begins. The flame failure response is reset between more than 0.5 seconds and less than or equal to 0.8 seconds, 10 seconds after initial flame sense. The manufacture recommends that the furnace system be inspected once a year by a qualified service person. NOTE: If the flame is established in any of the 12 attempts and flame failure time is set and then the proof the flame is lost, the control will recycle to re-attempt for a total of 11 retrials beginning from pre-purge (including) before entering into lockout. Anytime the flame is established, the retry counter is zeroed and the control enters normal operating loop where all input/outputs are continuously checked. When the thermostat is satisfied (contacts open) thermostat de-activations period starts. After the completion of the thermostat de-activation time of 3 seconds the gas valve and inducer motor are de-energized, the indoor air blower 45 second delay off period starts and the proof of the flame is lost. COOLING On a call for cool, the thermostat contact close signaling the control module. After the thermostat activation period of 3 seconds, the microprocessor runs its self-check routine verifying normal condition of all inputs/outputs (I/O). The control energized the compressor indoor blower contactor. After the control has entered into a normal operating loop, all the input/outputs are continuously checked for compliance with all other sections. When the thermostat is satisfied the compressor contactor is de-energized and the blower delay off period starts. After the delay to blower off timing (45 seconds), the indoor air blower relay is de-energized. 8 Unitary Products Group

9 PRE-START CHECK LIST Complete the following checks before starting the unit. 1. Check the type of gas being supplied. Be sure that it is the same as listed on the unit nameplate. 2. Make sure that the vent and combustion air hoods have been properly installed. OPERATING INSTRUCTIONS 1. STOP! Read the information on the unit safety label. 2. Set the thermostat to the lowest setting. 3. Turn off all electrical power to the unit. START-UP 2. Check for correct manifold gas pressures. See Checking Gas Input. 3. Check the supply gas pressure. It must be within the limits shown on rating nameplate. Supply pressure should be checked with all gas appliances in the building at full fire. At no time should the standby gas line pressure exceed 13", nor the operating pressure drop below 4.5" for natural gas units. If gas pressure is outside these limits, contact the local gas utility for corrective action. MANIFOLD GAS PRESSURE ADJUSTMENT N4Y Small adjustments to the high-fire gas flow may be made by turning the pressure regulator adjusting screw on the automatic gas valve. Refer to Figure DO NOT try to light the burners by hand. This appliance is equipped with an ignition device which automatically lights the burners. 5. Remove the access panel. 6. Turn the gas valve manual sellector arm to the OFF position. 7. Wait five (5) minutes to clear out any gas. If you then smell gas, STOP! Follow B in the information on the unit safety label. If you don t smell gas, go to the next step. 8. Turn the gas valve manual sellector arm to the ON position. 9. Replace the control access panel. 10. Turn on all electric power to the unit. MANUAL SELECTOR ARM SHOWN NPT (INLET) WHITE-RODGERS VALVE PRESSURE REGULATOR ROBERT SHAW VALVE MANUAL GAS COCK KNOB 11. Set the thermostat to the desired setting. 12. If the unit 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 UNIT 1. Set the thermostat to the lowest setting. 2. Turn off all electric power to the appliance if service is to be performed. 3. Remove the control access panel. 4. Turn the gas valve manual sellector arm to the OFF position. DO NOT FORCE. 5. Replace the control access panel. POST-START CHECK LIST (GAS) After the entire control circuit has been energized and the heating section is operating, make the following checks: 1. Check for gas leaks in the unit piping as well as the supply piping. FIG. 6 - GAS VALVE Adjust as follows: PRESSURE REGULA- MANIFOLD ADJUSTMENT SCREW 1. Remove the cap on the tower. See Figure 6 for location. 2. To decrease the gas pressure, turn the adjusting screw counterclockwise. 3. To increase the gas pressure, turn the adjusting screw clockwise. NOTE: The correct manifold pressure for natural gas furnaces is 3.5 IWG ±0.2. The correct manifold pressure for propane (LP) gas is 10.0 IWG ±0.2. BURNER INSTRUCTIONS To check or change the burners, CLOSE THE MAIN MANUAL SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE UNIT. 1. Open the unit fitting in the supply line. See Figure NPT (OUTLET) Unitary Products Group 9

10 N4Y 2. Disconnect the wiring to the gas valve, hot surface ignitor and flame sensor. 3. Loosen the four (4) #10 screws holding the manifold in place. 4. Pull the manifold gas valve assembly out of the unit. 5. Burners are now accessible for service. HOT SURFACE IGNITOR INSTRUCTIONS To check or change the ignitor, CLOSE THE MAIN MANUAL SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE UNIT. 1. Disconnect the wiring to the ignitor. 2. Remove the one screws holding the ignitor in place. 3. Pull the ignitor straight out. REMOTE SENSOR INSTRUCTIONS To check or change the remote sensor, CLOSE THE MAIN MANUAL SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE UNIT. NOTE: The sensor is located on the bottom of the burner manifold. 1. Disconnect the remote sensor wiring. 2. Remove the screw shoulder combination holding the sensor in place. 3. Pull the sensor straight out. ADJUSTMENT OF TEMPERATURE RISE The temperature rise (or temperature difference between the return air and the heated air from the furnace) must lie within the range shown on the AGA or CGA rating plate and the data in Tables 2 and 3. After the temperature rise has been determined, the CFM can be calculated as follows: F Temp. Rise = After about 20 minutes of operation, determine the furnace temperature rise. Take readings of both the return air and the heated air in the ducts about six feet from the furnace where they will not be affected by radiant heat. Increase the blower CFM to decrease the temperature rise; decrease the blower CFM to increase the rise. DIRECT DRIVE BLOWER BTUH Input BTUH Input (OR) CFM = 1.35 x CFM 1.35 x F Temp. Rise All units have direct drive multi-speed blower motors. Refer to the unit wiring diagram and connect the blower motor for the desired CFM. CHECKING GAS INPUT NATURAL GAS 1. Turn off all other gas appliances connected to the gas meter. 2. With the furnace turned on, measure the time needed for one revolution of the hand on the smallest dial on the meter. A typical gas meter usually has a 1/2 or a 1 cubic foot test dial. 3. Using the number of seconds for each revolution and the size of the test dial increment, find the cubic feet of gas consumed per hour from Table 9. If the actual input is not within 5% of the furnace rating with allowance being made for the permissible range of the regulator setting, replace the orifice spuds with spuds of the proper size. NOTE: To find the BTU input, multiply the number of cubic feet of gas consumed per hour by the BTU content of the gas in your particular locality. (Contact your gas company for this information since it varies widely from city to city.) TABLE 8 - GAS RATE-CUBIC FEET PER HOUR Seconds Size of Test Dial for One Rev. 1/2 cu. ft. 1 cu. ft Example: By actual measurement, it takes 38 seconds for the hand on the 1-cubic foot dial to make a revolution with just a 100,000 BTUH furnace running. Using this information, locate 38 seconds in the first column of Table 9. Read across to the column headed 1 Cubic Foot, where you will see that 95 cubic feet of gas per hour are consumed by the furnace at that rate. Multiply 95 x 1050 (the BTU rating of the gas obtained from the local gas company). The result is 99,750 BTUH, which is close to the100,000 BTUH rating of the furnace. SECURE OWNER S APPROVAL When the system is functioning properly, secure the owner s approval. Show him the location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust temperature settings within the limitations of the system. 10 Unitary Products Group

11 MAINTENANCE N4Y NORMAL MAINTENANCE CAUTION: Prior to any of the following maintenance procedures, shut off all power to the unit, to avoid personal injury. Periodic maintenance consists of changing or cleaning filters and lubricating the venter motor. Under some conditions, the main burners should be cleaned. FILTERS - Inspect once a month. Replace Disposable or clean Permanent Type as necessary. DO NOT replace Permanent Type with Disposable. MOTORS - Indoor and outdoor fan motors are permanently lubricated and require no maintenance. Venter motor is factory lubricated for an estimated 10 year life. Motor may be oiled annually using 6 drops of Anderaol 402 to extend its life. CAUTION: DO NOT over-lubricate venter motor. OUTDOOR COIL - Dirt should not be allowed to accumulate on the outdoor coil surface or other parts in the air circuit. Cleaning should be as often as necessary to keep the coil clean. Use a brush, vacuum cleaner attachment, or other suitable means. If water is used to clean the coil, be sure that the power to the unit is shut off prior to cleaning. NOTE: Exercise care when cleaning the coil so that the coil fins are not damaged. Do not permit the hot condenser air discharge to be obstructed by overhanging structures or shrubs. BURNER - At the beginning of each heating season, make a visual check of the main burner flame. If it is not possible to adjust for the proper flame, the burners may need cleaning. TO CLEAN BURNERS - Remove them from the furnace as explained in Burner Instructions. Clean burners with hot water applied along top of the burner. COMBUSTION AIR DISCHARGE - Visually inspect discharge outlet periodically to insure soot and dirt buildup is not excessive. If necessary, clean to maintain adequate combustion air discharge. The manufacture recommends that the furnace system be inspected once a year by a qualified service person. CLEANING FLUE PASSAGES AND HEATING ELEMENTS With proper combustion adjustment the heating element of a gas fired furnace will seldom need cleaning. If the element should become sooted, it can be cleaned as follows: 1. Remove the burner assembly as outlined in BURNER INSTRUCTIONS. 2. Remove the screws holding the flue collector box. 3. Unscrew and lift out the flue baffles. 4. Using a wire brush on a flexible wand, brush out the inside of each heat exchanger from the burner inlet and flue outlet ends. 5. Brush out the inside of the flue collector box and the flue baffles. 6. If soot build-up is particularly bad, remove the vent motor and clean the wheel and housing. 7. After brushing is complete, blow all brushed areas with air or nitrogen. Vacuum as needed. 8. Replace parts in the order they were removed in steps 1 thru 3. Unitary Products Group 11

12 Unitary Products Group P.O. Box 1592, York, Pennsylvania USA Subject to change without notice. Printed in U.S.A. Copyright by York International Corporation All Rights Reserved N4Y