Troubleshooting - Hitachi RUA-NP5ATS Instruction Manual

10. TROUBLESHOOTING

Troubleshooting Charts
The following charts show efficient checking procedures for trouble.
：Fault
No Cooling
No Cooling (Compressor Does Not Start)
Stopped
Evaporator
Fan Motor
Operating
Unit Power Supply
Stopped
Condenser
Fan Motor
Operating
：Check
Faulty
Blown
Fuses for Operation
Circuit
Tripped
Overcurrent Relay
for Evaporator Fan
Faulty
Evaporator Fan
Motor Contactor
Tripped
Internal Thermostat
for Condenser Fan
Faulty
Compressor
Contactor
TROUBLESHOOTING
：Cause
No Brackets：Remedy
------------------------------- Obtain the Correct Voltage
No Voltage or Low Voltage
Single-Phase ------------------------------- Repair the Power Line
Shorted Components
------------------------------- Repair or Replace the
Loose Connections ------------------------------- Tighten the Connections
High Voltage or Low Voltage
------------------------------- Obtain the Correct Voltage
Single-Phase or Phase Imbalance ------------------------------- Check the Power Supply
Faulty Fan Bearing ------------------------------- Replace the Bearing
Excessive Fan Belt Tension ------------------------------- Adjust Belt Tension
Excessive Fan Load
------------------------------- Check Fan Speed and the
Burned Coil
------------------------------- Replace the Contactor
Faulty Contact ------------------------------- Repair the Contacts
Defective Operation Switch ------------------------------- Repair or Replace the Switch
High Voltage or Low Voltage ------------------------------- Obtain Correct Voltage
------------------------------- Check the Power Supply
Single-Phase or Phase Imbalance
------------------------------- Repair or Replace if Required
Other Faulty Electrical Components
------------------------------- Replace the Contactor
Burned Coil
Faulty Contact ------------------------------- Repair the Contacts
Open Compressor Windings
------------------------------- Replace the Compressor
Incorrect Wiring ------------------------------------ Correct the Wiring
Components
to the Motor：
Repair When Required
Ducting System
to the Motor：
Repair When Required
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