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19
Replacing the compressor
Refrigerant recovery method
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 PC 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 PC 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
PC 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 PC 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] [* .] [* ] [* ]
Summary of Contents for A90-0132
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