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Related Manuals for Lennox MPGA 075 B3
Summary of Contents for Lennox MPGA 075 B3
- Page 1 APPLICATION GUIDE GAS FURNACE Fit’s All 80 English/02-2004...
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Page 3: Table Of Contents
AFFIX LABEL HERE INSTALLATION AND SERVICING INSTRUCTIONS UPFLOW, DOWNFLOW OR HORIZONTAL GAS-FIRED NON-CONDENSING WARM AIR FURNACE Issue 0240 TABLE OF CONTENTS Safety ......... . . Gas Connections . -
Page 4: Safety
SAFETY The following is a list of safety precautions and their locations in this manual. These safety rules and precautions must be followed when installing this furnace. 1. Use only with type of gas approved for this furnace. Refer to the furnace rating plate. - Page 6 FURNACE BLOWER SPECIFICATIONS AND AIR FLOW DATA EXTERNAL STATIC (IN. W.C.) BLOWER BLOWER SYSTEM SPEED MPGA050B3 (10X6 WHEEL) (1/3HP MOTOR) MPGA075B3 (10X6 WHEEL) (1/3HP MOTOR) MPGA075B4 (12X9 WHEEL) (1 HP MOTOR) MPGA100B4 (10X9 WHEEL) (1 HP MOTOR) MPGA100B5 (12X9 WHEEL) (1 HP MOTOR) MPGA125B5 (12X12 WHEEL)
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Page 7: Furnace Wiring Specifications
FURNACE WIRING SPECIFICATIONS 20541501 Issue 0240 Page 5 of 26... -
Page 8: Introduction
The furnace cabinet must have an uninterrupted or unbroken electrical ground to minimize personal injury if an electrical fault should occur. The unit must also be electrically grounded in accordance with local codes, or in the absence of local codes, with the latest edition of the (U.S.) National Electrical Code ANSI/NFPA No. 70 or CSA Standard C22.1;... - Page 9 Do not place combustible material on the furnace Failure to comply with all of the clearances will jacket. Failure to comply with this warning will create a fire hazard. create a fire hazard. The furnace should also be located as near to the center of the air distribution system as possible, and This furnace is not watertight and is not designed should be installed level.
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Page 10: Air For Combustion And Ventilation
AIR FOR COMBUSTION AND VENTILATION For purposes of this instruction the following Contaminated Combustion Air: This furnace is not to be installed in a structure definitions apply: defined as having contaminated combustion air. Allowing exposure to substances containing chlorine or fluoride Confined Space: A space whose volume is less could harm the furnace and void the warranty. - Page 11 If ventilation and/or combustion air must be supplied to the "Confined Space" from inside the building structure, two permanent openings to an additional room of sufficient volume as to combine the volumes of the spaces to meet the criteria for an "Unconfined Space" must be created. Each opening must have a free area of not less than one square inch per 1000 Btu per hour of total input of all appliances within the "Confined Space"...
- Page 12 Figure 4 When horizontal ducts are used to supply air from the outdoors, they must be of the same cross sectional area as the free area of the openings to which they connect. CONFINED SPACE / OUTDOOR AIR The minimum dimension of rectangular air ducts must not FROM ATTIC be less than 3 inches.
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Page 13: Ducting
DUCTING The proper sizing of warm air ducts is necessary to insure satisfactory heating operation. Ductwork should be in accordance with the latest editions of (U.S.) NFPA-90A (Air Conditioning Systems) and NFPA-90B (Warm Air Heating and Air Conditioning Systems) or Canadian equivalent. viewed for possible openings using light assistance or Ductwork Recommendation: The supply duct work should be attached to the... -
Page 14: Venting
Filters: 2. In parallel flow installation, dampers must be provided to direct air over the furnace heat exchanger when Air filters must be used in every installation. For side heat is desired and over the cooling when cooling is return installations, air filters must be installed external to the furnace casing. - Page 15 be repaired or the "B" vent must be replaced. Table 4 AUXILIARY DRAFT INDUCERS 2. Inspection to ascertain that the vent system is clear Vent Kit MFR Model * Furnace Input and free of obstructions. Any blockage must be Field Controls Co. 50000, 75000, 100000 or SWG-4G cleared before installing this furnace.
- Page 16 4. All pipe should be supported using the proper clamps combustion blower adaptor plate to the flue collector and/or straps. These supports should be at least box, taking care to support the blower assembly so every four (4') feet. that it does not fall. 5.
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Page 17: Electrical Connections
CARBON MONOXIDE POISONING HAZARD Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon monoxide poisoning or death. The following steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation: 1. -
Page 18: Gas Connections
GAS CONNECTIONS Gas piping shall be of such size and so installed as Figure 11 to provide a supply of gas sufficient to meet maximum GAS CONTROL PIPING demands without undue loss of pressure between the gas meter and the furnace. It is recommended that the gas line to the furnace shall be a separate line direct from the meter, unless the existing gas line is of ample capacity. -
Page 19: Theory Of Operation
THEORY OF OPERATION 20541501 Issue 0240 Page 17 of 26... - Page 20 STARTUP AND OPERATIONAL CHECKOUT 1. Be sure all electrical power is OFF. 2. Check all wiring using proper wiring diagram on Do not use this furnace as a construction heater. inside of the control box cover. Use of this furnace as a construction heater 3.
- Page 21 Remove the cap to access the screw for input TABLE 5 adjustment (Figure 13 Pressure Regulator). Turn Gas Rate (Cubic Feet per Hour) regulator-adjusting screw IN to increase pressure, TEST DIAL TEST DIAL OUT to decrease pressure. Replace the cap. Measure Seconds for Seconds for the manifold pressure.
- Page 22 Burner Orifice Sizing: TABLE 7 The furnace is supplied with standard orifices for the High Altitude Manifold Pressure Derate gas shown on the rating plate. Table 6 shows (with standard 42 orifice Natural / 54 orifice LP sizes) combinations of heating values and specific gravities for *Heating Value of Natural Gas Altitude (BTU/FT3)
- Page 23 Adjust the blower speed so that the temperature rise Figure 16 is within the rise specified on the rating plate. Consult the FLAME ROLLOUT SWITCH wiring diagram for speed changes on the direct drive motor. Limit Control Checkout: After the furnace has been in operation for at least 15 minutes, restrict the return air supply by blocking the filters or closing the return registers and allow the furnace to shut down on high limit.
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Page 24: Sequence Of Operation
SEQUENCE OF OPERATION Direct ignition system control 20541501 Issue 0240 Page 22 of 26... -
Page 25: Servicing The Furnace
SERVICING THE FURNACE 8. Reattach all wiring and piping as per the wiring diagram and installation instructions. ELECTRICAL SHOCK, FIRE OR EXPLOSION 9. Turn on utilities and check for leaks using soapy HAZARD water and a brush. 10. A visual check of the main burner should be made at Failure to follow safety warnings exactly could result the beginning of each heating season. - Page 26 4. Disconnect wires from rollout switch. Replacement 5. Remove manifold or burner/manifold assembly. 1. Place the blower in the blower opening of the unit and reconnect the auxiliary limit leads. Manifold ONLY 2. Slide the blower back, into the unit, taking care to a.
- Page 27 TROUBLE SHOOTING With LED Indicator Assistance 20541501 Issue 0240 Page 25 of 26...
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Page 28: Wiring Diagram
WIRING DIAGRAM 20541501 Issue 0240 Page 26 of 26... - Page 29 USER'S INFORMATION MANUAL Gas-Fired Furnace READ ALL INSTRUCTIONS IN THIS MANUAL AND RETAIN THIS AND ALL ADDITIONAL INSTRUCTIONS FOR FUTURE REFERENCE. Congratulations..you have one of the most modern gas furnaces made. Your unit has been carefully selected to keep you warm and comfortable during the winter months.
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Page 30: Safety
For your safety - A flood-damaged furnace is extremely dangerous. Attempts to use the furnace can result in fire or explosion. Read before operating A qualified service agency should be contacted to inspect the furnace and to replace all gas controls, control system Here are a few "Do's and Don'ts"... -
Page 31: Temperature Control
11. Set the thermostat to the desired setting. Fan Operation You may wish to increase your comfort by setting your 12. If the furnace will not operate, follow the instructions system for continuous air circulation of the indoor air. in "To Turn Off Gas to Furnace" and call your The fan switch on the thermostat permits you to do this. -
Page 32: Maintenance Of Your Furnace
authorized dealer at once to obtain a qualified service Maintenance Of Your Furnace inspection: • Rust, flakes, or other deposits • Coatings • Corrosion Always shut off all power to the unit before attempting any of the following maintenance Even if no unusual rust or other conditions are observed, procedures. -
Page 33: Cleaning/Replacing The Filter
The vent from your furnace may rise vertically and If your air distribution system has a central return air filter- terminate above the roof. When horizontal venting an grille, you do not need a filter in your furnace. Clean the 80% furnace, an approved sidewall venter must be used. -
Page 34: Parts Replacement Information Guide
Warranty Procedure When warranty parts are required: 1. Be prepared to furnish the following information: a. Purchaser's name b. Complete model number, serial number, and date of installation. c. An accurate description of the problem or defective parts. 2. Contact your dealer or distributor. Keep this User's Information Manual (including Warranty) and proof of purchase for your records. - Page 35 Owner Record Furnace Model # Serial # Installation Date INSTALLED BY: Dealer Address Telephone # License # Contact Person Other Equipment Installed: Equipment Type Model # Serial # Installation Date Equipment Type Model # Serial # Installation Date Equipment Type Model # Serial # Installation Date...
- Page 37 FA-AGU-0204-E Due to Lennox's ongoing commitment to quality, Specifications, Ratings and Dimensions subject to change without notice and without incurring liability. Improper installation, adjustment, alteration, service or maintenance can cause property damage or personal injury. Installation and service must be performed by a qualified installer and servicing agency.