Trouble Shooting Refrigeration System; Colour Of Compressor Oil - Mitsubishi Heavy Industries SRK-ZSP-S Service Support Handbook

Location Extra Low Low
High Side
High Side
High Side
High Side
•
High Side
Low Side
Low Side
Low Side
Low Side
Low Side
•
Low Side

Colour of Compressor oil

TROUBLE SHOOTING REFRIGERATION SYSTEM

Refrigerant Pressure
Normal High
•
•
•
•
Cause
Extra High
Excessive refrigerant overcharge
•
Non condensibles in the system
Faulty outdoor fan motor
•
Blocked outdoor unit heat exchanger
Liquid flooded outdoor heat exchanger
High indoor return air temperature
Excessive load
Insufficient refigerant
Gas leak
Blockage
Ineffective compressor compression
Liquid refrigerant flooding back from indoor unit
•
Bypass valve open
•
Mixture of non condensibles
High indoor return air temperature
•
High ambient temperature
Mixture of non condensibles
Lack of Load
Restricted/Blocked liquid line
Low refrigerant charge
Blocked filter
Indoor fan fault
Dirty indoor unit heat exchanger
Sample Oil State
Number
0 - 1 Normal
2 - 3 Slight moisture contamination
4 - 5 High temperature or high moisture content
6+ Compressor motor burnout