Carrier 38mvc018 3 Service Manual
Here you can view all the pages of manual Carrier 38mvc018 3 Service Manual. The Carrier manuals for Air Conditioner are available online for free. You can easily download all the documents as PDF.
Page 31
31 CHART 3 -- COMPRESSOR OVERCURRENT PROTECTION Is unit running in outdoor ambient higher than 125 °F?Beyond operating range Outdoor coil clean?Clean coil. Problem persists?Problem solved Check connections from OD board. Corrosion, or high resistance Outdoor fan Ok? Connect gauges to unit. pressures ok? Check amp draw to compressor? Values within range? Replace outdoor board Replace compressorClean/repair connection Problem persists?Problem solved Change outdoor motor High head, high suction? High...
Page 32
32 CHART 4 -- INDOOR UNIT COMMUNICATION ERROR SIZE 9K AND 12K Reset main power and restart system using remote. Problem persists? . No further action is required No Yes Measure Volts DC on outdoor TB between 1 & 3. Ok?** Yes Check the wires and connections between Indoor and outdoor units* No Fix connection or replace wiring No Yes Replace outdoor board. ** There is a 2 to 3 minute window to take the measurement before the diagnostic light is on again.Measure Volts DC on indoor TB between 1 & 3....
Page 33
33 CHART 5 -- OUTDOOR UNIT PROTECTS Suction and head equal? Outdoor coil clean?Clean coil. Problem persists? Check sensors. Flow Chart #2 Connect gauges to unit. Pressures ok? Check compressorNormal suction, high head? Non condensables in sys. Pump down and recharge unit High head, high suction? Unit is overcharged. Reclaim charge and weigh in correct charge High head, low suction? Yes No No No No Problem solved No No Yes Yes Yes Yes Yes Yes Yes Check application limits Check outdoor unit board....
Page 34
34 CHART 6 -- INDOOR UNIT COMMUNICATION ERROR SIZE 18K AND 24K * Make sure wires are connected per connection diagrams i.e. L1 to L1 and L2 to L2. Failing to do that will result in a communication error. ** There is a 2 to 3 minute window to take measurements before the diagnostic light is on again. Reset main power and restart system using remote. Problem persists? . No further action is required No Yes Measure VDC reading on outdoor between S and G. Reading positive? ** Yes Check the wires and...
Page 35
35 CHART 7 -- UNIT NOT RUNNING, NO DIAGNOSTIC CODE Yes Use auto forced function. Unit runs? Reset remote and restart the unit. Is unit running? Problem solved Check batteries. OK? Replace battery Go to chart #13 Reset circuit breaker. Is unit running? Yes Problem solvedIs there power to outdoor unit? Yes Check fuse on outdoor board. Ok? Yes Check input and output on outdoor board. Ok? Check components. Ok? Flow charts 10 thru 12 Yes No Replace defective componentCheck wiring and circuit breaker and...
Page 36
36 CHART 8 -- UNIT NOT RUNNING OPTIMALLY Suction and head equal? Outdoor coil clean?Clean coil. Problem persists? Indoor filter clean?Clean filter. Problem persists? Check indoor fan motor Connect gauges to unit. Pressures ok?Replace indoor fan motor. Check compressorNormal suction, high head? High head, high suction? Unit is overcharged. Reclaim charge and weigh in correct charge High head, low suction? Yes Yes Yes No No No No Problem solved Problem solved No No No No No Yes Yes Yes Yes Yes Yes...
Page 37
37 CHART 9 -- UNIT NOT RUNNING OPTIMALLY (HP IN HEATING)* Visually check outdoor Unit for ice blockage. **Check reversing valve. Go to flow chart #12 No Yes Yes Check defrost sensor. Ok?No Replace sensor Check application limits. Ok? ** Check for blockage on outdoor coil and drain pan. Are the holes in drain pans blocked? NoBeyond operating range Yes Yes Check ambient conditions. Prime icing? Explain to customer Visually check outdoor Unit for ice blockage. **Check reversing valve.No Yes Yes Check...
Page 38
38 CHART 10 -- COMPRESSOR Check contactor output on outdoor board if not done already. If bad, replace outdoor board. * For size 9 and 12k units contactor is on outdoor board. Trace connections from OD board. Connections ok? Check compressor windings. Ok?No fix connection No Yes Check capacitor. Capacitor ok? Yes Check contactor.* Contactor ok? NoReplace contactor Yes NoReplace capacitor NoReplace compressor No Compressor ok. Trace connections from OD board. Connections ok? Check compressor...
Page 39
39 CHART 11 -- OUTDOOR MOTOR Trace connections from OD board. Connections ok? Motor ok. Fix connectionNo YesYes No Replace capacitors YesNo Replace motor Check capacitor. Capacitor ok? Check motor windings. Ok? Visually confirm that fan blades and outdoor coil are not blocked. Clear blockage Yes No Trace connections from OD board. Connections ok? Motor ok. Fix connectionNo YesYes No Replace capacitors YesNo Replace motor Check capacitor. Capacitor ok? Check motor windings. Ok? Visually confirm that...
Page 40
40 CHART 12 -- REVERSING VALVE Check RV connection on outdoor board. Ok? Clean or repair the connectionNo Yes Yes Check RV output on outdoor board. Ok? No Replace outdoor board Replace reversing valve. Yes Check RV solenoid. Ok? Replace solenoid No Check RV connection on outdoor board. Ok? Clean or repair the connectionNo Yes Yes Check RV output on outdoor board. Ok? No Replace outdoor board Replace reversing valve. Yes Check RV solenoid. Ok? Replace solenoid No CHART 13 -- RECEIVER BOARD Check...