Mitsubishi Electric PURY-HP144, Service Handbook

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[8-13 Parts Replacement Instructions ]
68
- chapter 8 HWE18220_GB
8 Troubleshooting Based on Observed Symptoms
Four-way valve (21S4a)
Four-way valve (21S4a)
Four-way valve (21S4a) LEV (LEV2d)
Remove the braze here.
Remove the braze here.
Remove the braze here.
Cut the pipe here.
Remove the
braze here.
Cut the pipe here.
Remove the
braze here.
Remove the
braze here.
Replacement procedure for the four-way valve (21S4a)
(7A) Cut the pipe below four-way valve (21S4a) and in the middle with a pipe cutter as shown in the figure.
Cut the pipe below four-way valve (21S4a) and in the back with a pipe cutter as shown in the figure.
After cutting the pipe in three sections as indicated in the figure, remove the braze at the three areas shown in Figure 7.
(8A) Remove the pipe below four-way valve (21S4a) and on the front by removing the braze at the three areas shown in Figure
8.
Figure 7
Figure 8
The replacement parts for this part is
included with the replacement kit that
contains four-way valves (21S4a and
21S4b). Use the parts included with
the four-way valve.
After being removed, leave the pipes at
the bottom inside the unit. (Once removed
from the unit, it will be difficult to re-place
the pipes.)
*Notes on replacing refrigerant circuit components (four-way valve, solenoid valve, and LEV)
Be sure to perform non-oxidized brazing.
Before heating the pipes, wrap the refrigerant circuit components with a wet towel to keep the temperature of the
components from rising above 120°C.
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.
Wet felt sheets listed below (or its equivalent), and place them 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")