Mitsubishi Heavy Industries SRK100VNXPZSX Technical Manual page 81

(g) Over-current protection current safe controls I, II
Detecting the outdoor unit inverter input (primary) current and the output (secondary) current, if the current values exceed
setting values, the compressor speed (frequency) is controlled to protect the inverter.
Retention
Reset
B
Current (A)
(Fig. C) The control value "A" and the reset value vary depending
on the compressor speed.
24
22
20
18
16
Reset valve B
14
12
40 50 60
Compressor speed (frequency) (rps)
(h) Power transistor temperature protection
(i) Protective control
If the power transistor temperature (detected with TIP) exceeds the setting value, the compressor speed (frequency)
is controlled to suppress the rise of power transistor temperature.
Reset
Power transistor temp. (°C)
(i) Anomalous power transistor current
(i) Prevents over-current on the inverter. If the current value in the power transistor exceeds the setting value, the
compressor stops.
(ii) If the current value in the power transistor exceeds the specified value and the compressor stops 4 times within 30
minutes, E42 is displayed on the remote control and it enters the anomalous stop mode.
(j) Anomalous inverter PCB
If the power transistor detects any anomaly for 15 minutes, including the stop of compressor, E51 is displayed on the
remote control and it enters the anomalous stop mode.
(k) Anti-frost control by the compressor frequency control
(i) If the indoor unit heat exchanger temperature (detected with Th2) exceeds the setting value at 4 minutes after the
start of compressor, the compressor speed (frequency) is controlled to initiate the anti-frost control of indoor unit
heat exchanger.
(ii) When there are 2 indoor unit heat exchanger temperatures (Th2), the lowest temperature is detected.
Reduces compressor frequency
at each minute.
(iii) Regarding the anti-frost control by the operation stop, refer to the operation control function by the indoor unit
control and the cooling, dehumidifying frost prevention of page 71.
Reduces frequency
at each minute.
A
Control valve A
70 80 90 100 110 120 130
Reduces compressor frequency
at each minute.
Retention
81 85
Retention
1.5 3.5
Indoor unit heat exchanger temp. (°C)
-
Model
Control
value A
Primary FDC100 11.0 (23.0) 10.0 (22.0) 11.0 (23.0) 10.0 (22.0)
current
side FDC125, 140 11.0 (23.0) 10.0 (22.0) 11.0 (25.0) 10.0 (24.0)
FDC100 11.5 (Fig.C) 10.5 (Fig.C) 11.5 (Fig.C) 10.5 (Fig.C)
Secandary
current
side FDC125, 140 11.5 (Fig.C) 10.5 (Fig.C) 11.5 (Fig.C) 10.5 (Fig.C)
Note (1) Value in ( ) are for the single phase models.
Reset
80
-
'17 • PAC-T-257
Cooling Heating
Reset Control
value B value A value B
Reset