Troubleshooting Guide - Panasonic CS-MA90KE Service Manual

Troubleshooting Guide

1. Relationship between the condition of the air conditioner and pressure and
electric current
Condition of the air
conditioner
Insufficient refrigerant
(gas leakage)
Clogged capillary tube
or Strainer
Short circuit in the
indoor unit
Heat radiation defi-
ciency of the outdoor
unit
Inefficient
compression
Carry out the measurements of pressure, electric current, and temperature fifteen minutes after an operation is
started.
2. Diagnosis methods of a malfunction of a compressor and a 4-way valve
Nature of fault
Insufficient compressing of a
compressor
Locked compressor
Inefficient switches of the 4-way valve
Cooling Mode
High Pressure
Low Pressure
Electric current during operation becomes approximately 20% lower than the
normal value.
The discharge tube of the compressor becomes abnormally hot (nor-
mally 70 to 90°C).
The difference between high pressure and low pressure becomes
almost zero.
Electric current reaches a high level abnormally, and the value exceeds the
limit of an ammeter. In some cases, a breaker turns off.
The compressor is a humming sound.
Electric current during operation becomes approximately 80% lower than
the normal value.
The temperature difference between from the discharge tube to the 4-way valve
and from suction tube to the 4-way valve becomes almost zero.
Electric
Low Pressure
current during
operation
Symptom
– 42 –
CS-MA90KE
Heating Mode
Electric
High Pressure
current during
operation