Replacement Of Expansion Valve - Hitachi SAMURAI Series Service Manual

3. Servicing
Cycle components

3.3.5 Replacement of expansion Valve

1 Collect the refrigerant as explained in section
"3.3.3 Recovering the refrigerant"
2 Firmly hold the coil of the expansion valve and
pull out upward. It is easier to remove the ex-
pansion valve coil if it is rotated while pulling it
up.
3 Remove the brazed parts using a blowtorch and
previously cooling the pipe side with wet cloth
in order to avoid brazing material entering the
pipe circuit.
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).
70
SMGB0097 rev.0 - 07/2015
Expansion
valve coil
Expansion
valve
Brazed
parts