Mitsubishi Electric PQHY-P120THMU-A, Service Handbook

Page: 12 / 414

[
I
Read Before Servicing ]
- 3 - HWE09080 GB
I
Read Before Servicing
[1] Read Before Servicing
1. Check the type of refrigerant used in the system to be serviced.
Refrigerant Type
Multi air conditioner for building application CITY MULTI WY/WR2 THMU-A/YHMU-A series: R410A
2. Check the symptoms exhibited by the unit to be serviced.
Refer to this service handbook for symptoms relating to the refrigerant cycle.
3. Thoroughly read the safety precautions at the beginning of this manual.
4. Preparing necessary tools: Prepare a set of tools to be used exclusively with each type of refrigerant.
Refer to "Necessary Tools and Materials" for information on the use of tools.(page 4)
5. Verification of the connecting pipes: Verify the type of refrigerant used for the unit to be moved or replaced.
Œ
Use refrigerant pipes made of phosphorus deoxidized copper. Keep the inner and outer surfaces of the pipes clean and free
of such contaminants as sulfur, oxides, dust, dirt, shaving particles, oil, and water.
Œ
These types of contaminants inside the refrigerant pipes may cause the refrigerant oil to deteriorate.
6. If there is a leak of gaseous refrigerant and the remaining refrigerant is exposed to an open flame, a poisonous gas
hydrofluoric acid may form. Keep workplace well ventilated.
CAUTION
Œ
Install new pipes immediately after removing old ones to keep moisture out of the refrigerant circuit.
Œ
The use of refrigerant that contains chloride, such as R22, will cause the refrigerating machine oil to deteriorate.