Mitsubishi Electronics PCH24GK, PCH36GK OC277-36, Indoor coil temperature abnormality detection

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(5) Detecting abnormalities in the outdoor unit

When the outdoor unit is determined to be abnormal by the following causes, the compressor will stop and the check code “ P8 ” will appear on the remote controller display.

( i ) During compressor ON while hot adjustment is set.

1If the difference between the indoor coil temperature and room temperature is in the RANGE B, the indoor fan will

stop.

2Within 20 minutes after entering RANGE B (except for the first 10 seconds), a) If the temperature difference enters RANGE A, the hot adjustment starts,

b) If the temperature difference is still in RANGE B, the outdoor unit is deemed abnormal. c) If the temperature difference enters RANGE C, defrosting starts.

3 Within 20 minutes after entering RANGE C, if the temperature difference does not return to RANGE B,the outdoor unit is deemed abnormal.

4 If the temperature difference returns to RANGE B, the next 20 minutes is an allowance period. If the difference enter

RANGE A during the allowance, defrosting ends and the hot adjustment starts. If the difference does not enter RANGE A during the allowance, the outdoor unit is deemed abnormal.

( ii ) During compressor ON in defrosting

After 30 minutes of defrosting in hot adjustment, if the temperature difference is still in RANGE C, the outdoor unit is determined to be abnormal.

When RANGE B does not change to RANGE A after 20 minutes have passed since RANGE C had outdoor unit is determined to be abnormal.

( iii ) During compressor OFF Not detecting abnormalities.

(6)Indoor coil temperature abnormality detection

An abnormality can be detected during compressor ON, except for the following.

For the first 30 minutes after the temperature difference between the indoor coil temperature and room temperature enters the RANGE C.

When the temperature difference enters the RANGE C until it moves to the RANGE B.

(7)Defrosting operation

After the outdoor unit starts the defrosting operation, when the temperature difference between the indoor coil temperature and room temperature gets out of RANGE A and into RANGE B, the indoor unit starts the defrosting mode. After the out- door unit stops the defrosting operation, when the temperature difference returns to the RANGE A, the indoor unit stops the defrosting mode. While the indoor unit is in the defrosting mode, the indoor fan and the booster heater stop.

w1 RANGE A : Indoor coil temperature is more than 9 degrees above room temperature. RANGE B : Indoor coil temperature is within 9 degrees either way of room temperature. RANGE C : Indoor coil temperature is more than 9 degrees below room temperature

Indoor coil temperature minus room temperature

(degree)

+9

0

-9

RANGE A

RANGE B

RANGE C

OC277-36

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Contents Contents OC277-1Features OC277-2Easy Maintenance no Maintenance Necessary for 2500 Hours OC277-3Improving Efficiency of Piping Work Part Names and Functions OC277-4Remote controller operation buttons OC277-5Remote controller display OC277-6Specifications OC277-7Models PCH24GK, PCH30GK, PCH36GK, PCH42GK Data OC277-8Models PCH24GK, PCH30GK, PCH36GK, PCH42GK Performance Data CFM SHC TPCOC277-9 CFMOC277-10 Performance CurveOC277-11 PCH36GK Cooling Capacity PCH36GK Heating CapacityOC277-12 Condensing Pressure and Suction PressureOC277-13 PCH30GKOC277-14 PCH36GKOC277-15 PCH42GKOC277-16 Standard Operation DataSHF PCH24GK PCH30GK PCH36GK PCH42GK OC277-17 Operating RangeOutlet AIR Speed and Coverage Range Additional Refrigerant Charge R22ozOC277-18 Noise Criterion Curves PCH24GKPCH30GK PCH36GK PCH42GKOutlines and Dimensions OC277-19Indoor unit PCH24GK OC277-20 Indoor unit PCH30/36/42GKRefrigerant System Diagram Remote controllerOC277-21 PCH30GK PCH36GK PCH42GKWiring Diagram Model PCH24/30/36/42GK Wiring DiagramOC277-22 Operation FLOW-CHART OC277-23Main Operation OC277-24 Cooling OperationOC277-25 DRY OperationDRY YESOC277-26 Heating OperationMicroprocessor Control OC277-27Outline of Microprocessor Control How to operate OC277-28Indoor Unit Control Compressor controlOC277-29 Start conditionCoil frost protection Termination conditionsOC277-30 Auto vane controlSwing Auto ReturnOC277-31 Detecting abnormalities in the outdoor unitRange a Range B Range C DRY operation time chart How to operate OC277-32DRY operation OC277-33 Heat operation time chart OC277-34Heat operation Display in Heat operationOC277-35 Overheat protectionBooster heater control Overheat preventionIndoor coil temperature abnormality detection OC277-36Defrosting operation Initial mode How to operate Mode changeTemperature range OC277-37OC277-38 COOL/DRY operationAuto return Timer operation Timer functionOC277-39 Test run Before test runOC277-40 Emergency operationBefore emergency operation Dip switch functions On remote controller boardOC277-41 On indoor controller boardFan motor max. rotational frequency Service Ref OC277-42PCH24GK PCH30GK PCH36GK PCH42GK SW7 OFF PCH36, 42GKTrouble Shooting Remote Controller Display AbnormalityOC277-43 When malfunction occurs during operation For group control using one remote controllerOC277-44 Example Check Unit code addressOC277-45 Wrong Wiring on Site OC277-46Cool HeatOC277-47 Other Troubles and CausesHow to check the parts OC277-48PCH OC277-49 System Control OC277-50Variety of System Control Functions PAC-SA89TA-EGroup Control with a Single Remote Controller How to wireHow to set unit-address OC277-51Control Using TWO Remote Controllers Remote ON-OFF and Individual Remote ControlsHow to set SW17-7 See Figure Remote controller LCD indicationIndividual Control by Grouping the Remote Controllers Basic wiringSwitch function of remote ON-OFF switch OC277-53Multiple Remote Control Display Timer Operation or the Operation by AN External SignalOC277-54 Auto Restart FunctionDisassembly Procedure PCH24GK Operating ProcedureOC277-55 Removing the air intake grilleOC277-56 Removing the fan motorRemoving the sirocco fan Removing the side panelOperating Procedure Photos OC277-57Removing the vane motor Removing the Indoor coil thermistorOC277-58 Removing the drain panRemoving the guide vane Remove the intake grilleOC277-59 Removing the support heaterRemoving the heat exchanger Parts List OC277-60Structural Part PCH24GK OC277-61 OC277-62 Structural Part PCH30GK PCH36GK PCH42GKOC277-63 OC277-64 FAN and Heater Parts PCH24GKOC277-65 FAN and Heater Parts PCH30GK PCH36GK PCH42GKOC277-66 Electrical Parts PCH24GK10 PCH30GK PCH36GK PCH42GKTimer Optional PartsOC277-67 PAC-SC32PTA Weekly Timer Setting Display OC277-68Names and functions SET Back DisplayTimer Adapter Multiple Remote Controller AdapterOC277-69 Refrigerant PipesSpecifications are subject to change without notice