Checking Components; Check Refrigerant System - Hitachi RPIL-1.0PNN1DH Service Manual

3. CHECKING COMPONENTS

3. Checking components

3.1 Check refrigerant system

TEST SYSTEM FLOW
Conditions: ① Compressor is running.
② The air condition should be installed in good ventilation.
Tool: Pressure Gauge
Technique: ① see ② feel ③ test
See ----- Tube defrost.
Feel ----- The difference between tube's temperature.
Test ----- Test pressure.
Cooling mode
Test system pressure.
Is the low pressure
normal at service
part ?
The pressure on the
low side.
The system needs
refrigerant.The
service people must
add refrigerant. Does
the low pressure
rise ?
NO
The refrigerant system is
blocked. Please check
the Capillary Tube （or
electronic
expansion valve).
Is it blocked?
yes
Unsolder the capillary tube
ASS'Y(or electronic expansion
valve). The capillary tube1 is
blown by N .
2
The pressure on the
high side.
Recharge refrigerant
after air purging with
the vacuum
pump. Is the low
pressure normal
over again?
yes
Air remains at the
refrigerant system.
yes
Recharge
refrigerant.
NO
Check check valve and 4-
way valve.
NO
If the pressure is
close to static
NO
pressure?
yes
4-way valve collude or
compressor exhaust very
ebb.
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