for the 5 BUTTON 3109228.001 AIR CONDITIONER COMFORT ...

1 1 AIR CONDITIONERBULLETIN A29/2 AJANUARY 2002 INTRODUCTIONThe COMFORT Control Center control system can be used tooperate the following Duo-Therm Units:Roof Top Air ConditionersRoof Top Heat PumpsBasement Air ConditionersBasement Heat PumpsDual Basement Air ConditionersDual Basement Heat PumpsOther Manufacturer s FurnacesA majority of air CONDITIONER and heat pump problems areelectrical and can be found very find a problem in the electrical system, you need to beable to diagnose the following:1. Power Source10. PTCR Assembly11. Heat Strip3. Ambient Sensor5. Motors14. Configuration6. Remote Sensor15. COMFORT Control Center7. Wiring16. System Power Module17. DC Voltage9. Reversing ValveTOOLS REQUIREDThe air CONDITIONER can be checked with a voltmeter, ohm-meter, clamp-on ammeters and two good clamp-on ammeters can read voltage and the5 BUTTON COMFORT CONTROLCENTER TROUBLE-SHOOTING FOR COMFORTCONTROL CENTER (CCC)CONTROLSFor detailed troubleshooting, refer to sec-tion Air CONDITIONER /Heat Pump turned on No displaya.

2 Reset - Sec. B15b. DC Voltage - Sec. B17c. Cable Assembly - Sec. B2d. AC Control Module - Sec. Control Center (CCC) - Sec. B152. Air CONDITIONER /Heat Pump turned on Has display, improper operationa. Power Source - Sec. B1b. Reset - Sec. B16c. Configuration - Sec. B14d. Wiring - Sec. B7e. AC Control Module - Sec. Control Center (CCC) - Sec. B153. Air CONDITIONER /Heat Pump turned on Fan runs, No compressor operationa. Start Relay/PTCR - Sec. B10b. Start Capacitor - Sec. B5c. Fan/Run Capacitor - Sec. B4d. Cold Control - AC Only, Sec. B12e. Outdoor Ambient Sensor (HP) - Sec. - Sec. B3g. Wiring - Sec. Control Center - Sec. Control Module - Sec. B84. Air CONDITIONER /Heat Pump turned on Com-pressor runs, No fan operationa.

3 Fan/Run Capacitor - Sec. B4b. Motor - Sec. B5c. Wiring - Sec. Control Center (CCC) - Sec. B15e. AC Control Module - Sec. Pump turned on Compressor runs andfan runs, No heat Valve - Sec. B9b. Wiring - Sec. B7c. AC Control Module - Sec. B8 Form No. 1/02(French ) 2002 Dometic CorporationLaGrange, IN 46761 FIG. TROUBLESHOOTINGFOR COMFORT CONTROLCENTER (CCC) CONTROLSWe will now start electrically troubleshooting COMFORT Con-trol Center (CCC) controlled units. The best place to beginis at the power POWER SOURCEIf the compressor or fan fails to operate, it is probably notreceiving power. Be sure the power cord is plugged in andno fuses or breakers are : Many customers use extremely long power cordsthat are undersized.

4 If possible, ask the owner to hook upthe RV just like it was when the problem note of the wire size and length of wire. Compare it tothe chart for wire normal operation of the unit, AC voltagemust stay between VAC and of the unit outside of this voltagerange can result in component determine if power is reaching the air CONDITIONER , theinside plastic air diffuser box must be removed. The junctionbox will now be exposed. Remove the cover from the junc-tion box to gain access to the connection between the RVand the unit wires (FIG. 3). Check with a voltmeter for volt-age at the connections of the unit to RV wires. USE CAU-TION as 115 volts may be no voltage is present, the problem is in the coach wiring orbreaker/fuse CABLE ASSEMBLYA flat control cable must be routed from the unit to the Com-fort Control Center.

5 It must be 26 gauge, stranded copperwire, four (4) conductor (yellow, green, red, and black). Thecable must be terminated with a four (4) position telephoneRJ-11 : Do not use a pre-made telephone extension order of the connectors is reversed and will cause afailure of the 3 FIG. 2 CURRENTWIRE SIZEINAMPS1614121086 LENGTH IN FEET547761211922164861038609615324315254 06410216220304876121 FIG. 43 The cable should be made in the following manner:Cut the control cable to the desired length. When cuttingmake sure ends are cut straight, not diagonally. Next, usean RJ-11 connector crimping the stripper section of the tool to remove the outer insu-lation of the cable. Be careful not to remove or break thecolored insulation of the inner conductors.

6 Repeat on oppo-site the prepared cable into the RJ-11 plug. When insert-ing cable you MUST be sure that the black wire is on yourleft as you look at the top of the plug. See FIG. 5. Insert theRJ-11 plug into the tool and squeeze to the stop. Repeatthe procedure for other finished cable can be tested with a com-fort control cable tester. See Section B16 for more informa-tion on the testing of the COMPRESSORThe compressor motor can be electrically checked. Besure to disconnect all power and turn all switches to the OFF position, before starting to do the the terminal cover from the compres-sor and disconnect the three leads connectedto the terminals. Make note of the positionsso the wires can be replaced an ohmmeter to check for continuity through the over-load device.

7 If no continuity is found and the compressor ishot, allow 15 to 20 minutes for the compressor to cool. If arepeat of the test shows the overload to be open, it is defec-tive and requires should exist between all three terminals of thecompressor. If there is no continuity the compressor wind-ings are open and the compressor is the compressor casing to bare metal and checkcontinuity from each terminal to the casing. If continuity isfound to the casing on any of the terminals, the compressoris shorted and it is CAPACITORSDuo-Therm air conditioners and Heat Pumps use three dif-ferent capacitors: 1) compressor run capacitor 2) compres-sor start capacitor and 3) fan/blower capacitor. On someFIG. 5units the compressor run and fan/blower capacitor are inthe same compressor run and fan/blower capacitor are housed ina steel or aluminum case.

8 The start capacitor is in a bake-alite or plastic shell. Some have a 15,000 ohm bleederresistor across the power must be turned OFF and capacitors must bedischarged before making the test. Use an AC voltmeter(set to the highest scale) or a 15,000 ohm 2 watt resistor tobleed away any charge left in the the wires from the terminals and inspect the cas-ing. If it is bulged, cracked or split, the capacitor is an analog voltmeter (dial or hand reading indicator) totest the capacitor after it has been discharged. Set theohmmeter to mid-range and check for resistance to the resistance to the case from the terminals indicates it isdefective and it needs to be the ohmmeter to the highest scale and read across theterminals on the capacitor.

9 The ohmmeter should swingtowards zero and slowly move back towards infinity. Re-verse the leads and repeat the test. If the ohmmeter stayson infinity, it is open and needs to be replaced. If very littlemeter movement is noticed, switch the meter to a lowerscale and repeat capacitors with the 15,000 ohm resistor should bechecked on the 1,000 ohm scale. The ohmmeter shouldswing below 15,000 ohms and return. Reverse leads andrepeat test. If the capacitor does not act as described it isdefective and needs to be MOTORSTo determine if a motor is good, test the windings with anohmmeter. Disconnect the power supply, and turn all theswitches to the OFF position. Disconnect the motor leads(on some models disconnect the 6 pin plug from the electri-cal box).

10 The motor should show continuity between allleads and the white wire. Infinity or no continuity indicatesthe winding is open and the motor is for continuity between the motor frame and each a continuity reading is present to any lead, the motor isshorted and motor can be tested with an ammeter to determine ifthe operation is within the rating ( 10%) listed on the modelplate. Many times the motor windings will check good, butbad bearings or capacitor may be found in an ampere REMOTE SENSORThe remote sensor is the temperature sensor that allowsthe unit for a zone to cycle ON and OFF by remote sensor is used for each unit or zone. A remotesensor is usually optional for zone 1; but, in some applica-tions the COMFORT Control Center is located for convenienceof access and the remote sensor placed for the circuit is competed to a particular componentand that component will not operate, the problem isin the roof top Roof Top Heat PumpThe operation of the AC control box can be checkedat the 6-pin plug connection.