Service manual

Replacing the Compressor
Refrigerant Recovery Method
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Refrigerant Recovery Method for a Failed Outdoor Unit
When multiple outdoor units are connected in a system, the refrigerant can be recovered from
the outdoor unit to be repaired by performing the reclaim operation to a functional outdoor
unit.
* NOTE 1: The refrigerant recovery ratio changes according to the outside temp., etc. After
reclaim operation, recover the remaining gas using a recovery device, etc., and be
sure to measure the recovered refrigerant amount. During reclaim, it is necessary
to heat the accumulator and compressor bottom to increase the recovery ratio.
* NOTE 2: Once complete, the system cannot be operated until the failed outdoor unit
has been completely repaired.
(Continuous operation is unavailable because of refrigerant over-charge.)
* NOTE 3: If PMV A and B are fully closed due to failure, this reclaim function is not available.
In this case, recover all refrigerant in the system.
Work procedure (A)
When back-up operation has not been utilised.
A-1) Turn on the power source of all the outdoor units, and keep the system in stop
status (Indoor unit stop).
If insulation resistance of the failed outdoor unit compressor is insufficient, remove the
compressor cable before turning on the power source.
A-2) For the failed outdoor unit, complete the following operations.
1) Close the liquid service valve fully. (Keep the gas pipe and balancing pipe valve
opened fully.)
2) Set the rotary switches on the interface P.C. board to the following numbers:
• SW03 [No.1]/SW02 [No.11]/SW01 [No.2]
• 7 segment display: [r .][d ][ ][ ]
3) Push switch SW04 on the interface P.C. board for 5 seconds or more.
Steps ‘a’ to ‘e’ should occur.
* To cease work at any time, turn off the power source of all the outdoor units or
push switch SW05 on the interface P.C. board.
a. 7 segment display: [r .][d ][1 ][1 ]
b. The outdoor unit fan operates.
c. PMVA and PMVB open.
d. Solenoid valves SV3A, SV3B, and SV3C are turned on.
e. Other outdoor units start automatic operation in trial cooling mode.
(Compressor activation is time controlled.)
4) Press the push-switch SW04 on the interface P.C. board for approx. 2 seconds.
The present refrigerant pressure data (MPaG) is displayed.
• 7 segment display: [H ][ * .][ * ][ * ] ( *: Value of Pd pressure sensor)
• With every press of the push-switch SW04 the display changes.
Initial display Pd pressure: [Pd] Ps pressure: [Ps]
[r .][d ][1 ][1 ]

[H ][ * .][ * ][ * ]

[L ][ * .][ * ][ * ]