York SUNLINE DCG Series Installation Manual

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York SUNLINE DCG Series Installation Manual Manual pdf 54 page image

290699-YIM-B-060754 Unitary Products GroupOn calls for heating, the supply air blower operates butthe draft motor does not (the room thermostat fanswitch is in the “AUTO” position).1. The draft motor has inherent protection. If themotor shell is hot to the touch, wait for the internaloverload to reset.2. If the motor shell is cold with the room thermostatcalling for heat, check if 24 volts is present at theroom thermostat but not at the UCB, check forproper wiring between the thermostat and theUCB, i.e. that the thermostat “W1” terminal is con-nected to the “W1” terminal of the UCB, and forloose wiring.3. The draft motor is a 230 volt draft motor on all mod-els regardless of unit supply voltage. If the ICB isflashing a code other than the heartbeat, then trou-bleshoot the device indicated by the fault code. Ifnot, then remove power to the unit for more than20 seconds. If upon restoring the power to the unitthe draft motor does not start with a call for heat,then verify that terminal “L1” of the ICB has a mini-mum of 120 volts to ground on 230 and 460 voltmodels or a minimum of 18 volts to ground on 575volt models. If terminal “L1” does not have the min-imum voltage, then check the wiring between theunit control box and the ICB on all models and on460 volt models, the transformer in the gas heatcompartment and its wiring. If terminal “L1” doeshave the minimum voltage, then check for the min-imum voltage on terminal “IND” of the ICB on sin-gle stage models and terminal “IND HIGH” of theICB on two stage models. If voltage is not presentat the terminal, then verify wiring between the con-trol box and the ICB. If all wiring is intact, then ICBis at fault. If voltage is present at the terminal on230 and 460 volt models, then the draft motor is atfault. On 575 volt models, if voltage is present atthe terminal, then check the draft motor relay DMRmounted above the ICB. First verify that the relay ispulled in by visual inspection. If not, then verify theminimum voltage is present between terminals “A”and “B” of the relay. If the minimum voltage is notpresent, then check the wiring. If it is present, thenverify that a minimum of 150 volts is present at ter-minals “5” and “7” of the draft motor relay. If notpresent at terminal “7” of the draft motor relay, thentroubleshoot the transformer in blower section andits wiring. If present at terminal “7” and not at termi-nal “5” of the draft motor relay, then the relay is atfault. If the minimum voltage is present at terminal5 of the draft motor relay, then the draft motor is atfault.The ignitor sparks at the pilot burner but the pilot doesnot ignite and a gas odor is detected at the draft motoroutlet.1. Adjust the pilot adjust screw on the gas valve asdescribed in “PILOT CHECKOUT” on page 47.2. Check the supply pressure as described in “POSTSTART CHECK LIST” on page 46. Make adjust-ments as necessary.3. Check the pilot orifice and pilot burner for obstructionas described in paragraph above. Clean as neededbut the problem should not be the gas valve.The pilot burner ignites but the ignitor continues tospark and the main burners do not ignite.1. Make the same checks and adjustment asdescribed in “PILOT CHECKOUT” on page 47.2. Check the supply pressure as described in “POSTSTART CHECK LIST” on page 46. Make adjust-ments as necessary.3. Make sure that the pilot burner is not bent or dam-aged.4. Make sure that the ground connections at the pilotburner, gas valve and ignition control are intact.Check the ignitor wire for good electrical connec-tion. If all are intact, replace the ignition control.The pilot burner lights and the spark stops but the mainburners do not light.1. Check electrical connections between the ignitioncontrol and the gas valve. If intact, check for 24volts across terminals “MV” and “GROUND” termi-nals. If no voltage detected, replace ignition con-trol. If voltage is present, replace gas valve.Main burners light but exhibit erratic flame characteristics.1. Adjust air shutters as described in “BURNER AIRSHUTTER ADJUSTMENT” on page 47.2. Check the main burner orifices for obstruction andalignment. Removal procedure is described inBURNER INSTRUCTIONS on page 47. Clean orreplace burner orifices and burners as needed.UNIT FLASH CODESVarious flash codes are utilized by the unit controlboard (UCB) and the ignition control board (ICB) to aidin troubleshooting. Flash codes are distinguished bythe short on and off cycle used (approximately 200mson and 200ms off). To show normal operation, the con-trol boards flashes a 1 second on, 1 second off “heart-beat” during normal operation. This is to verify that the

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