Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 369

[ IX Troubleshooting ]
1. Explained below are procedures for replacing water-cooled heat exchanger assembly parts.
1. Applicable models
• PQHY-P72, 96, 120ZLMU-A
• PQRY-P72, 96, 120ZLMU-A
2. Parts to be serviced
The procedures apply to the service parts listed in the table below.
No. Parts to be replaced
1 Water-cooled heat
exchanger assembly
3. Procedures
* Precautions for starting replacement
• Check that the main power supply is OFF.
• Check that no refrigerant is in the heat source unit.
Remove each part according to the 1)-8) procedures on the next page before replacing service parts.
Mount the removed parts back in place in a reversed procedures of 1)-8) on the next page after replacing service
parts.
(1) Water-cooled heat exchanger assembly replacement procedures
Removal procedures
1 Hang the beam of the INVERTER HEX assembly from the four-way valve piping to keep the INVERTER HEX assem-
bly from falling downward, using a wire.
Remove the duct and the solenoid valve block support.
2
3 Hang the solenoid valve block from the four-way valve to keep the solenoid valve block from falling downward, using a
wire.
Unbraze the brazed part of the pipe assembly (header assembly) , and remove the fixing screws holding the water
4
heat exchanger.
5 Remove the water-cooled heat exchanger fixing screws, and pull out the water-cooled heat exchanger.
Installation procedures
6 Install the replacement water heat exchanger.
7 Reinstall the water heat exchanger fixing plate, fixing screws, solenoid valve block support, and duct as they were.
* Precautions for replacing water-cooled heat exchanger assembly
• Be sure to perform no-oxidation brazing when brazing.
• After brazing, check the condition around the brazing. After confirming no leakage, evacuate the air
inside. (*1)
• Perform brazing with care of the flame direction so that it does not burn cables and plates etc. in the unit.
*1: Refer to Chapter I [8] Vacuum Drying (Evacuation) for detailed procedure.
HWE15150
Required materials
Water-cooled heat exchanger service parts kit
- 360 -
Qty.
1
GB