Mitsubishi Electric PUHY-HP120TNU-A, Service Handbook

Page: 251 / 324

[8-12 Parts Replacement Instructions ]
54
- chapter 8 HWE18240_GB
8 Troubleshooting Based on Observed Symptoms
8-12-3 Four-way Valve and Check Valve Replacement Procedure
1. L-module (four-way valve (21S4a))
Compressor cover (top)
Compressor cover (front)
Figure 2
Figure 1
cable tie
TH4
TH15
Figure 3
Compressor cover (left)
Rubber bush
Figure 4
Figure 5
Cut the cable tie here.
Cut the cable tie here.
Enlarged view
Explained below is the procedure for replacing four-way valve (21S4a) (on the right when seen from the front of the unit).
Secure sufficient work space before starting maintenance work. (See 8-12-1 Ensuring Maintenance Space (Preparation for the
Maintenance of Refrigerant Circuit Parts).)
(1) Remove the top compressor cover by unscrewing the three screws. (See Figure 1.)
Remove the compressor cover by unhooking the hooks on the back.
(2) Remove the front compressor cover by unscrewing the four screws. (See Figure 2.)
(3) Cut the two cable ties holding TH4 and TH15, and remove the wiring from the rubber bush on the left compressor cover.
(See Figure 3.)
(4) Remove the left compressor cover by unscrewing the two screws. (See Figure 4.)
(5) Remove the plastic cover and the coil holding solenoid valves 2, 9, and 10 (SV2, 9, and10). Remove the thermal insulation
shown in Figure 5. (See Figure 5.)
Thermal insulation (180 mm x 70 mm x 10 mm thick)
*Included with the four-way valve replacement parts
Use the insulation material included with the four-way
valve.
Solenoid valve coils 2, 9, and 10
(SV2, 9, and10) and coil cover