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5
−
3
T-318
CONDITION
POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.7 ABNORMAL PRESSURES (COOLING)
High discharge pressure
Condenser coil dirty
Condenser fan rotating backwards
Condenser fan inoperative
Refrigerant overcharge or noncondensibles
Discharge pressure regulator valve defective
Discharge service valve partially closed
Open
Suction modulation valve malfunction
Low suction pressure
Suction service valve partially closed
Open
Filter-drier partially plugged
Low refrigerant charge
Expansion valve defective
No evaporator air flow or restricted air flow
Excessive frost on evaporator coil
Evaporator fan(s) rotating backwards
Discharge pressure regulator valve defective
Suction modulation valve malfunction
Suction and discharge
pressures tend to equalize
when unit is operating
Heat exchanger defective
Replace
Compressor valves defective
Compressor cycling/stopped
Check
5.8 ABNORMAL NOISE OR VIBRATIONS
Compressor
Loose mounting bolts
Tighten
Worn bearings
Worn or broken valves
Liquid slugging
Insufficient oil
Condenser or Evaporator Fan
Bent, loose or striking venturi
Check
Worn motor bearings
Bent motor shaft
5.9 MICROPROCESSOR MALFUNCTION
Will not control
Defective Sensor
Defective wiring
Check
Fuse (F1, F2) blown
Replace
Stepper motor suction modulation valve circuit malfunction
5.10 NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW
Evaporator coil blocked
Frost on coil
Dirty coil
No or partial evaporator air flow
Evaporator fan motor internal protector open
Evaporator fan motor(s) defective
Evaporator fan(s) loose or defective
Evaporator fan contactor defective
Replace
Содержание 69NT40-541-300
Страница 2: ......
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Страница 128: ......
Страница 131: ...7 3 T 318 Based on Drawing 62 66058 Figure 7 2 SCHEMATIC DIAGRAM Units with 3 Phase Evaporator Motors...
Страница 133: ...7 5 T 318 6 Heater FCCH FCCH Figure 7 4 SCHEMATIC DIAGRAM Units with Normal Evaporator Fan Capability...
Страница 134: ...7 6 T 318 FCCH FCCH Figure 7 5 SCHEMATIC DIAGRAM Units with Single Evaporator Fan Capability...
Страница 136: ...7 8 T 318 To ST10 To TRX2 To QC1 To QC1 To QC1 To MC6 CONTROLLER Figure 7 7 SCHEMATIC DIAGRAM Emergency Bypass...
Страница 138: ...7 10 T 318 Based on Drawing 62 66058 Figure 7 9 UNIT WIRING DIAGRAM Units with 3 Phase Evaporator Motors Sheet 1 of 2...
Страница 139: ...7 11 T 318 Based on Drawing 62 66058 Figure 7 10 UNIT WIRING DIAGRAM Units with 3 Phase Evaporator Motors Sheet 2 of 2...
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