Cycle Troubleshooting Guide - LG Universal System Air Conditioner Service Manual

2. Cycle Troubleshooting Guide

Trouble analysis
1. Check temperature difference between intake and discharge air, and operating current.
Temp. Difference
Operating Current
Notice:
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relatively higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
2. Check temperature and pressure of refrigeration cycle.
Suction pressure
(Compared with (Compared with
the normal value) the normal value)
Higher
Lower
Notice:
1. The suction pressure is usually 4.5~6.0 kg/cm
2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with
putty.
Temp. difference
Current
Temp. difference
Current
Temp. difference
Current
Temp. difference
Temperature
High Defective compressor
Normal Excessive amount of
refrigerant
Insufficient amount of
Higher refrigerant(Leakage)
Clogging
: approx. 0°C
: less than 80% of
rated current
: approx. 8°C
: less than 80% of
rated current
: less than 8°C
: near the rated
current
: over 8°C
Cause of Trouble
G at normal condition.
2
Troubleshooting Guide
All amount of refrigerant leaked out.
Check refrigeration cycle.
Refrigerant leakage
Clog of refrigeration cycle
Defective compressor
Excessive amount of refrigerant
Normal
Description
Current is low.
High pressure does not quickly
rise at the beginning of operation.
Current is low.
Service Manual 81