Service
-
143
-
'10 • HM-T-149
③
However, when the control condition
①
is established during the control of the compressor protection start
Ⅲ
, LP alarm is displayed and E49 is recorded in Error Log at the rst stop of compressor and it enters the
anomalous stop mode.
6) Compressor pressure ratio protection control (FDCW100VNX only)
a) During heating operation, if the liquid line temperature of water heat exchanger (BT15=Thi-L) or condensing
satulated temperature (CST), whichever higher, and the outdoor heat exchanger temperature (Tho-R) exceed the
setting value after 10 minutes from compressor ON, the compressor speed (frequency) is controlled in order to protect
compressor.
b) This control is not performed under the following conditions
(1) Outdoor fan is stopped, or 10 minutes has not elapsed since the outdoor fan starts.
(2) 10 minutes has not elapsed since defrosting operation nishes.
0.150 0.280
Low pressure (MPa)
Reduce compressor speed
at every 1 minutes
Reset
68°C
50°C
Liquid line temperature of
water heat exchanger (Thi-L)
or
Condensing saturated
temperature (CST) (°C)
7) Overcurrent protection
a) Current safe control I
When the inverter primary current (CT current) reaches following value, the compressor speed
is reduced until it gets to the cancellation value.
Model Operation Mode Current (A)
FDCW71VNX
Cooling 15
Heating 16
FDCW100VNX
Cooling -
Heating 17
FDCW140VNX
Cooling 23
Heating 25
b) Current safe control II
Detecting the outdoor inverter output (secondary side) current, if the current values exceed setting values, the
compressor speed (frequency) is controlled in order to protect the inverter.
B
A
Reduce compressor speed
at every 1minute
Reset
Current (A)
Retention
12
14
16
18
20
22
24
5040 60 70 80 90 100 110 120 130
Control or reset valve (A)
Compressor speed (frequency) (rps)
(Fig. C) The control value “A” and the reset value vary depending
on the compressor speed.
Reset valve B
Control valve A
Model
Cooling Heating
Control
value A
Reset
value B
Control
value A
Reset
value B
FDCW71VNX 13 12 13 12
FDCW100VNX
Fig -C Fig -C Fig -C Fig -C
FDCW140VNX
Operation control function by the outdoor unit controller