234
4 Set rotary SW01/02/03 to 2/11/1.
[rd] [ ] are displayed.
¯
Push the push SW04 for 5 seconds or more.
5 [rd] [ FF] are displayed.
Trouble outdoor interface P.C. board
Header unit with trouble
Operation during pump down operation
Outdoor unit
Operation contents
Outdoor unit with trouble
Compressor stops.
Outdoor fan ON
PMV1 and PMV2 open.
SV3A/3B/3C/3D/3E ON
Other outdoor units
Operates in test COOL operation
3
If oil deteriorates due to
trouble of the compressor,
remove SV3A# connector.
1
Connected with check joint of
the liquid pipe and check joint at
low pressure side by a charge
hose and purge.
2
Close fully service valve at liquid side.
(Keep gas and balance side opened.)
13. REFRIGERANT RECOVERY
WHEN REPLACING THE COMPRESSOR
13-1. Refrigerant Recovery in the Troubled Outdoor Unit
A pump-down function if prepared to this system. For multiple outdoor unit system, execute pump-down by using the
normal outdoor units and refrigerant can be recovered from the outdoor unit to be repaired
13-1-1. Before Refrigerant Recovery Operation
Pay attention to the following items during pump-down operation.
Note 1) The refrigerant recovery rate changes with the outside temperature, etc. in the pump-down operation.
When the pump-down operation has finished, be sure to recover the remaining gas using a recovery device and
measure the recovered refrigerant amount. (Executing pump-down operation when pump-down operation is
operated with heating accumulator of the outdoor unit to be repaired improves refrigerant recovery rate.)
Note 2) After this work, the system cannot operate until the defective outdoor unit has been repaired.
(As the operation becomes refrigerant overcharge operation, a continuous operation is unavailable.)
Note 3) While both outdoor pulse motor valves are closed (cannot open the valves), the refrigerant in the heat exchanger
cannot be recovered. If executing welding after pump-down operation, recover the refrigerant in the heat ex-
changer before work.
13-1-2. Refrigerant Recovery Procedure
(In case of no backup operation for outdoor unit)
<Work procedure>
Turn on the power supply of the system, and stop status of system operation.
If a trouble is an insulation error of the compressor, remove wiring to the compressor before turning on the power supply.
[Setup for the outdoor unit with trouble]
1. Using a charge hose, connect the check joint of the liquid pipe and the check joint at low-pressure side, and then
purge the air in the hose. (To recover refrigerant in the heat exchanger and the liquid tank)
2. Close fully the service valve of the liquid pipe of the outdoor unit with trouble.
(Keep service valve of the gas pipe and the balance pipe opened.)
3. If it is considered that the oil has deteriorated due to trouble of the compressor, take off SV3A valve connector of the
outdoor unit with trouble so that the deteriorated oil does not flow in the other outdoor units.
4. Set the rotary SW01/02/03 to 2/11/1 on the interface P.C. board of the troubled outdoor unit and then push SW04 for 5
seconds or more after [rd] [ ] have been displayed on 7-segment display section.
5. [rd] [ FF] have been displayed on 7-segment display, and then a pump-down operation starts.
∗
When interrupting the operation, turn off the power supplies of all the outdoor units or push SW05 on the interface
P.C. board.
Summary of Contents for MMC-AP0151H
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