Hitachi Primairy Series - Page 33

3. CHECKING COMPONENTS
Test system flow
Cooling mode
Test system pressure.
Is the low pressure
normal at service
part ?
The pressure on the
high side.
The pressure on the
low side.
Recharge refrigerant
after air purging with
the vacuum
pump. Is the low
pressure normal
over again?
Air remains at the
refrigerant system.
yes
The system needs
refrigerant.The
service people must
add refrigerant. Does
the low pressure
rise ?
NO
Recharge
refrigerant .
yes
The refrigerant system is
blocked. Please check
the Capillary Tube
（or
electronic
expansion valve) Is
it blocked?
Unsolder the capillary tube
ASS'Y(or electronic expansion
valve).The capillary tube1 is blown
by N
2
.
Check check valve and 4-
way valve.
If the pressure is
close to static
pressure?
NO
NO
4-way valve collude or
compressor exhaust very
ebb.
yes
NO
yes
Heating mode
Test system
pressure. Is the high
pressure normal at
service part ?
The pressure on the
high side.
The pressure on the
low side.
Recharge refrigerant
after air purging with
the vacuum
pump. Is the high
pressure normal over
again?
Air remains at the
refrigerant system.
yes
The system needs
refrigerant. The service
people must add
refrigerant . Does the
high pressure rise in
heating mode?
NO
Recharge refrigerant
yes
If the pressure is close
to static pressure?
4-way valve collude or
compressor exhaust every
ebb.
yes
Check heat exchanger and
4-way valve.
NO
The capillary tube is
blocked.Unsolder the
capillary tube ASS'Y. The
capillary tube1 and
capillary tube2 is blown by
N
2
.
NO
Remove the back
panel."see"the
capillary tube1 and
capillary tube2.Is it
defrosting?
yes
NO
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