Refrigerant Collecting - Mitsubishi PUMY-P60NKMU Technical & Service Manual

10-4. REFRIGERANT COLLECTING (PUMP DOWN)
Perform the following procedures to collect the refrigerant when moving the indoor unit or the outdoor unit.
Turn off the circuit breaker.
Connect the low pressure side of the gauge manifold to the service port of the gas side stop valve.
Close the liquid stop value.
Supply power (circuit breaker).
● Start-up of the indoor-outdoor communication takes about 3 minutes after the power (circuit breaker) is turned on. Start the
pump-down operation 3 to 4 minutes after the power (circuit breaker) is turned ON.
Perform the test run for cooling operation (SW3-1: ON and SW3-2: OFF). The compressor (outdoor unit) and ventilators (indoor
and outdoor units) start operating and test run for cooling operation begins. After the cooling operation has been carried out
for approximately 5 minutes, set the outdoor service switch SW2-4 (pump down switch) from OFF to ON.
● Do not continue to operate for a long time with the switch SW2-4 set to ON. Make sure to switch it to OFF after pump down
is completed.
● Only set the SW3-1 and SW3-2 to ON if the unit is stopped. However, even if the unit is stopped and the SW3-1 and SW3-2
are set to ON less than 3 minutes after the compressor stops, the refrigerant collecting operation cannot be performed. Wait
until compressor has been stopped for 3 minutes and then set the SW3-1 and SW3-2 to ON again.
Fully close the gas stop valve when the pressure reading on the gauge drops 0.05 - 0.00 MPa (approx. 0.5 - 0.0 kgf/cm²).
Stop the air conditioner operation (SW3-1: OFF and SW3-2: OFF). Set the outdoor service switch SW2-4 from ON to OFF.
Turn off the power supply (circuit breaker).
● If too much refrigerant has been added to the air conditioner system, the pressure may not drop to 0.5 kgf/cm².
If this occurs, use a refrigerant collecting device to collect all of the refrigerant in the system, and then recharge the system
with the correct amount of refrigerant after the indoor and outdoor units have been relocated.
Warning:
When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.
The compressor may burst and cause injury if any foreign substance, such as air etc. enters the system.
OCH502C
108