York SUNLINE MagnaDRY DR180 Installation Manual

Also see for SUNLINE MagnaDRY DR 180: Submittal data sheet Installation manual

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York SUNLINE MagnaDRY DR180 Installation Manual Manual pdf 66 page image

127915-YIM-A-040566 Unitary Products GroupExample: By actual measurement, it takes 13 seconds for the hand on the 1-cubic foot dial to make a revolution with just a 300,000 Btuh furnace running.Read across to the column in the table above, headed “1 Cubic Foot”, whereyou will see that 278 cubic feet of gas per hour are consumed by the furnace atthat rate. Multiply 278 x 1050 (the Btu rating of the gas obtained from the localgas company). The result is 292,425 Btuh, which is close to the 300,000 Btuhrating of the furnace.ADJUSTMENT OF TEMPERATURE RISEThe temperature rise (or temperature differencebetween the return air and the heated air from the fur-nace) must lie within the range shown on the ratingplate and the data in the Gas Heat Application Table 4.After the temperature rise has been determined, thecfm can be calculated as follows:After about 20 minutes of operation, determine the fur-nace temperature rise. Take readings of both the returnair and the heated air in the ducts (about six feet fromthe furnace) where they will not be affected by radiantheat. Increase the blower cfm to decrease the temper-ature rise; decrease the blower cfm to increase therise. Refer to the Blower Motor and Drive DataTable 27.BELT DRIVE BLOWERAll units have belt drive single-speed blower motors.The variable pitch pulley on the blower motor can beadjusted to obtain the desired supply air CFM.TROUBLESHOOTINGCOOLING TROUBLESHOOTING GUIDEOn calls for cooling, if the compressors are operatingbut the supply air blower motor does not energize aftera short delay (the room thermostat fan switch is in the“AUTO” position).1. Turn the thermostat fan switch to the ON position.If the supply air blower motor does not energize, goto Step 3.2. If the blower motor runs with the fan switch in theON position but will not run after the first compres-sor has energized when the fan switch is in theAUTO position, check the room thermostat for con-tact between R and G in the AUTO position duringcalls for cooling.3. If the supply air blower motor does not energizewhen the fan switch is set to ON, check that linevoltage is being supplied to the contacts of the M3,contactor, and that the contactor is pulled in. Checkfor loose wiring between the contactor and the sup-ply air blower motor.4. If M3 is pulled in and voltage is supplied to M3,lightly touch the supply air blower motor housing. Ifit is hot, the motor may be off on internalTABLE 32: GAS RATE - CUBIC FEET PER HOURSecondsfor OneRev.Size of Test Dial1/2 cu. ft. 1 cu. ft.468104503002281809006004503601214161820150129113100903002572252001802224262882756964164150138129CFM Btuh Input x 0.8= 108. .x F Temp RiseoTroubleshooting of components may requireopening the electrical control box with thepower connected to the unit. Use extreme carewhen working with live circuits! Check theunit nameplate for the correct line voltage andset the voltmeter to the correct range beforemaking any connections with line terminals.Shut off all electric power to the unit prior toany of the following maintenance proceduresto prevent personal injury.Label all wires prior to disconnection when ser-vicing controls. Wiring errors can causeimproper and dangerous operation, whichcould cause injury to person and/or damageunit components. Verify proper operation afterservicing.