Mitsubishi Electric PUHY-HP120TNU-A, Service Handbook

Page: 271 / 324

[8-12 Parts Replacement Instructions ]
74
- chapter 8 HWE18240_GB
8 Troubleshooting Based on Observed Symptoms
(22) Before removing the front heat exchanger, protect the adjacent electrical components and the pipe covers with the
recommended felt that is soaked in water, and then remove the braze from the areas shown in Figure 16. (Standard front
heat exchanger: 4 areas)
To remove the rear heat exchanger, remove the braze from four areas. (See Figure 17.)
Notes for replacing refrigerant circuit components (heat exchanger)
Be sure to perform non-oxidized brazing.
After brazing is done, check that the brazing is done properly and check for leaks before vacuum-drying the pipes.
Direct the brazing torch flame away from the wiring and sheet metals inside the unit not to damage them.
Place the wet felt sheets listed below (or their equivalents) around the areas to be brazed to protect the heat
exchanger, pipes, and pipe covers from being damaged from the brazing torch flame.
Recommended felt sheets: Spatter felt 50CF-11 (5t x 1 m x 1 m) by TRUSCO Nakayama
Felt sheets that meet the JIS standard (JIS A 1323 type A "Flame retardant testing method for spark droplets of
welding and gas cutting on fabric sheets in construction works")
Remove the braze from
the areas encircled in
the figure.
Remove the braze from
the areas encircled in
the figure.
Removing the standard front heat
exchanger (Figure 16)
Removing the standard rear heat
exchanger (Figure 17)