II - 4
Processes and Functions
SM830052
2
1. Compressor Control
(4) When heating, if outdoor fan ≠ H , current capacity increase allowed is treated as current capacity increase inhib-
ited.
(5) If the compressor maximum discharge temperature ] 98 ˚C, the current capacity increase allowed is treated as
current capacity increase inhibited.
(6) Compressor discharge temperature protection control
If the discharge temperature of a compressor increases to abnormally high (about 108 ˚C) during operation , the
unit stops operation by thermo-off or an alarm message appears. For each of the compressors, if the unit stops
operation by thermo-off due to abnormally high discharge temperature 4 times within 5 minutes of starting, an
alarm message appears.
(7) Compressor current control
The current for the 2 compressors is controlled separately.
1 Lock current control
If the current for an operating compressor increases to above the corresponding
value in the table below, an alarm message appears.
Compressor capacity Lock current
50 Hz, 11.2 kw compressor 14.7 A
50 Hz, 14 kw compressor 20.4 A
2 Overload current
If the current for an operating compressor remains above the corresponding
value in the below table for 30 seconds, an alarm message appears.
Compressor capacity Lock current
50 Hz, 11.2 kw compressor 12.3 A
50 Hz, 14 kw compressor 17.1 A
(8) Warm up operation control
In initial operation after microcomputer initialization, and after reverse-cycle start control (explained in Section 3)
and 4-way valve switching control (explained in Section 5), the AC compressor occasionally takes as long as 20
minutes to start.
(9) Outdoor coil temperature control in cooling
1 Each area is monitored constantly, and if control moves into the thermo-off area, the unit stops immediately.
For the capacity decrease area, if it has been decreased once, it is not decreased again for 30 seconds.
2 This control is not performed during test operation.
3 Even if the thermostat is switched off, this control does not result in an alarm.
Outdoor heat exchange
Control
coil temperature
Thermo-off
Current capacity decrease 3 steps
Current capacity increase inhibited
Current capacity increase allowed
↑
66 ˚C
65 ˚C
64 ˚C
63 ˚C
62 ˚C
↓
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