Hitachi SAMURAI Series Service Manual page 98

3. Servicing
Cycle components
Pay attention to the following points when replacing an expansion valve.
a. This unit uses an electronic expansion valve, which is normally closed when the compressor stops. For this reason,
when the valve upstream of the expansion valve (liquid outlet valve of the heat exchanger) is closed, refrigerant
may accumulate between the liquid outlet valve of the heat exchanger and the expansion valve. In case of removing
the brazed part of the expansion valve, always conduct this work after selecting expansion valve manual output
function at the service menu in order to force the opening of the expansion valve, and release both the primary and
the secondary side.
b. After replacement of the expansion valve, the value managed by the control and the actual opening do not match.
In order to fix this, always conduct a zero point adjustment (power reactivation).
3.5.6 Replacement of the check valve
The best way to replace the check valve is disassembling it from its location and later, unbrazing it from the pipes. Follow
the next steps for a correct disassembling:
1 Remove the thermistor as explained in chapter
Replacement of the thermistor (Discharge, THMd)"
2 Remove the 4 screws that fixes the check valve to its lo-
cation at the discharge outlet.
3 Remove the 4 Allen screws that fixes the cover of the
check valve.
Once disassembled
4 Remove the cover of the check valve to protect the inner
parts from the heat of the blowtorch when disassembling
the pipes.
5 Remove the brazed parts using a blowtorch and previ-
ously cooling the pipe side and the check valve unit with
wet cloth in order to avoid brazing material enter inside
the pipes.
90
SMGB0082 rev.1 - 07/2015
"3.5.18
Discharge pipe
Thermistor THMd
Check valve
Allen screw (x4)
Brazed parts
Screw (x4)
Flat washer (x4)
Spring washer (x4)