Panasonic U-20ME1E81, Service Manual

Page: 17 / 177

1 - 9
2WAY SYSTEM
Control Functions-Outdoor Unit
1
3. Compressor Control
1 - 9
2WAY SYSTEM
Control Functions-Outdoor Unit
1
3. Compressor Control
3-7. Protection control
3-7-1. Compressor discharge temperature protection
Discharge temp.
The compressor capacity is controlled according to the table below.
3-7-2. Abnormal low pressure protection
The compressor capacity is controlled according to the table below.
*Discharge temperature that is used for this control is the highest temperature among all compressors.
106 deg
104 deg
103 deg
101 deg
Capacity goes down 2.0 HP
Capacity goes down 1.0 HP
Capacity goes down 0.5 HP
Compressor capacity cannot increase
Compressor capacity can increase
Compressor
capacity
decreases
105 deg
Stop If this temperature is detected at regular intervals, alarm appears.
Low pressure
0.25 MPa
0.17 MPa
Capacity goes up slowly
Capacity cannot increase
Capacity goes down
0.20 MPa
No restriction
3-7-3. Overcurrent protection of compressor
Current limitation of compressor is shown in the table below. This limitation is to protect the compressor, so that
the current of the power cable connected with the compressor is limited.
* For the inverter compressor, this is the secondary current from HIC board.
Inverter compressor
Limit current 2
Secondary
current
Max. current 2 H
unit : Amp.
10HP
21.8
19.3
18.3
8HP
19.6
17.1
16.1 12HP
17.6
15.1
14.1
14HP
21.0
18.5
17.5
16HP
22.5
20.0
19.0
18HP
21.0
18.5
17.5
20HP
21.0
18.5
17.5
Max. current 2 L
Constant speed compressor
Limit current
unit : Amp.
10HP 8HP 12HP
14.9
14HP
12.4
16HP
14.9
18HP
12.4
20HP
14.9
Limit current 2
Max. current 2 L
Stop If this current is detected at regular intervals, alarm appears.
Frequency of inverter compressor goes down.
Frequency of inverter compressor can increase.
Frequency of inverter compressor cannot increase.
Max. current 2 H
SM830204-05_2WAY SYS.indb 9 2015/01/21 16:59:59