Hitachi RAM-90QH5, Service Manual, Page: 40 / 83

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RAM-90QH5
Cooling
Unit 1
Compressor requirement
OH temperature
Reversing
valve
Unit 2
Unit 3
Unit 4
Unit 5
Turns on
for heating
Outdoor fan
Compressor
rotation speed
0 Pulse
0 Pulse
0 Pulse
20 sec 20 sec
480
Unit 1
Unit 2
Expansion valve
Unit 3
Unit 4
0
480
0
480
0
480
0
0 Pulse
Unit 5
480
0
[NDWN_ON]
[NDWN_OFF]
20 sec 20 sec
30 sec
Decreases by 100 min
—1
/30 sec.
Increases by 50 min
—1
/30 sec.
30 sec 30 sec
30 sec 30 sec 30 sec 30 sec
When one unit is operated for cooling