Mitsubishi Electric PUHZ-FRP71VHA Service Manual page 16

9-1. REFRIGERANT COLLECTING (PUMP DOWN)
The refrigerant collecting function is available by performing the following procedure.
1 Close the 2 liquid stop valves and the cylinder/hydro unit side gas valve.
Only the indoor unit side gas valve remains open.
2 Connect the 2 gas stop valve service ports with a hose.
3 Turn on the main power and wait for 3-4 minutes.
4 Press the SWP button on the outdoor controller board, then the refrigerant collecting operation starts.
5 After conf rming the low pressure is lowered to 0 MPa (gauge), close the indoor unit side gas valve.
The refrigerant collecting operation stops automatically in 5 minutes.
6 Turn off the main power.
Hose
Cylinder/
Indoor
Hydrobox
UNIT
UNIT
Warning:
Do not disconnect extension pipes during the refrigerant collecting operation is running.
If you open the stop valves to the air during the compressor is running, the pressure could be abnormal high level and this may
cause a rupture of the compressor or other hazardous situation.
* Use a refrigerant recovery machinery if the refrigerant collecting is not completed in case of long pipe length or too much refrig-
erant contained.
9-2. START AND FINISH OF TEST RUN (ATA only)
• Operation from the indoor unit
Execute the test run using the installation manual for the indoor unit.
• Operation from the outdoor unit
By using the DIP switch SW4 on the control board of outdoor unit, test run can be started and finished, and its operation
mode (cooling/heating) can be set up.
1 Set the operation mode (cooling/heating) using SW4-2.
2 Turn on SW4-1 to start test run with the operation mode set by SW4-2.
3 Turn off SW4-1 to finish the test run.
• There may be a faint knocking sound around the machine room after power is supplied, but this is
no problem with product because the linear expansion pipe is just moving to adjust opening pulse.
• There may be a knocking sound around the machine room for several seconds after compressor
starts operating, but this is no problem with product because the check valve itself, generates the
sound because pressure difference is small in the refrigerant circuit.
Note:
The operation mode cannot be changed by SW4-2 during test run. (To change test run mode, stop the unit by SW4-1,
change the operation mode and restart the test run by SW4-1.)
OCH544
Stop valve
Service port
4-way valve
Stop valve
Service port
Charge
plug
Accumulator
LEV-B LEV-C
LEV-A
Stop valve
Service port
Stop valve
* SV1/SV2/SV3 are closed when the power is not supplied.
S i t
SV3 SV1 SV2
Charge plug
High pressure
sensor(63HS)
High pressure
switch (63H)
Muffler
TH34
TH4
Compressor
16
TH6
TH3
ON
OFF
Stop
Cooling
<SW4>
1 2
Operation
Heating