Mitsubishi Electric Mr.SLIM PUHZ-RP1.6VHA Technical & Service Manual page 27

1. Refrigerant collecting (pump down)
Perform the following procedures to collect the refrigerant when moving the indoor unit or the outdoor unit.
1Before collecting the refrigerant, first make sure that the all of the SW5 DIP switches for function changes on the control
board of the outdoor unit are set to OFF. If all of the SW5 switches are not set to OFF, record the settings and then set all of
the switches to OFF. Now, start refrigerant collecting operation. After moving the unit to a new location and completing the
test run, set the SW5 switches to the previously recorded settings.
2Turn on the power supply (circuit breaker).
wWhen power is supplied, make sure that "CENTRALLY CONTROLLED" is not displayed on the remote controller. If
"CENTRALLY CONTROLLED" is displayed, the refrigerant collecting (pump down) cannot be completed normally.
3After the liquid stop valve is closed, set the SWP switch on the control board of the outdoor unit to ON. The compressor
(outdoor unit) and ventilators (indoor and outdoor units) start operating and refrigerant collecting operation begins. LED1 and
LED2 on the control board of the outdoor unit are lit.
wSet the SWP switch (push-button type) to ON in order to perform refrigerant collecting operation only when the unit is
stopped. However, refrigerant collecting operation cannot be performed until compressor stops even if the unit is stopped.
Wait three minutes until compressor stops and set the SWP switch to ON again.
4Because the unit automatically stops in about two to three minutes after the refrigerant collecting operation (LED1 is not lit
and LED2 is lit), be sure to quickly close the gas stop valve.
wIn case the outdoor unit is stopped when LED1 is lit and LED2 is not lit, open the liquid stop valve completely, and then
repeat step 3 three minutes later.
wIf the refrigerant collecting operation has been completed normally (LED1 is not lit and LED2 is lit), the unit will remain
stopped until the power supply is turned off.
5Turn off the power supply (circuit breaker.)
2. Unit replacement operation
When reusing the existing pipes that carried R22 refrigerant for the RP4, RP5 and RP6 models, replacement operation
must be performed before performing a test run.
1If new pipes are used, these procedures are not necessary.
2If existing pipes that carried R22 refrigerant are used for the RP3 model, these procedures are not necessary. (The replace-
ment operation cannot be performed.)
3During replacement operation, "C5" is displayed on "A-Control Service Tool(PAC-SK52ST)". (This is applied to only RP4,
RP5 and RP6 models.)
• Replacement operation procedures
1Turn on the power supply.
2Set DIP switch SW8-2 on the control board of the outdoor unit to ON to start replacement operation.
• The replacement operation is performed using the cooling system. Cool air will flow from the indoor unit during the replace-
ment operation.
• During the replacement operation,
control board of the outdoor unit flash together.
3Replacement operation requires at least two hours to complete.
• After setting switch SW8-2 to ON, the unit automatically stops after two hours.
• Replacement operation can be performed repeatedly by setting switch SW8-2 from OFF to ON. Make sure to perform the
operation more than 2 hours. (If the operation is performed less than 2 hours, the existing pipes cannot be cleaned
enough and the unit may be damaged.)
• If replacement operation is performed over 2 hours, this action is recorded into nonvolatile memory of control board.
4Set switch SW8-2 to OFF. (Replacement operation is completed.)
wThe unit can be operated normally by remote controller even if SW8-2 remains ON.
wIf the indoor temperature is less than 15:, the compressor will operate intermittently but the unit is not faulty.
3. Start and finish of test run
• 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.
1Set the operation mode (cooling/heating) using SW4-2.
2Turn on SW4-1 to start test run with the operation mode set by SW4-2.
3Turn 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.)
is displayed on the remote controller and LED1 (green) and LED2 (red) on the
TEST RUN
27
<SW4>
C D
ON
OFF
1 2
A B
A Stop C operation
B Cooling D Heating