Current Protection - Panasonic U-10MF1E8 Service Manual

14. Current Protection

(1) Fan motor
Alarm
P22 Occurs when the fan motor detects overcurrent, or when the motor is locked and does
not turn.
(2) Inverter compressor
Alarm
1
P16 Occurs during ordinary operation when overcurrent (32.5 A) is detected.
P26 Occurs under the same conditions as P16 when the inverter compressor is operating
at or above 80 Hz.
P29 Occurs when missing phase or overcurrent (48 A) is detected at inverter compressor
start.
H31 Occurs when HIC detects overcurrent (75 A), or when an abnormal high temperature
(150 °C) is reached.
The inverter current includes a primary current and secondary current. The alarm judgment utilizes both
currents. Generally, the secondary current is larger that the primary current.
(3) Constant-speed compressor
An alarm occurs when overcurrent or lock current is detected.
List of overcurrent and lock currents
Outdoor unit
type
8 hp
10 hp
12 hp
14 hp
16 hp
List of Alarms
Compressor
No.
Detected
current
Alarm display
(4) CT circuit detection trouble
Compressor 1 (inverter
compressor)
Compressor 2 (constant-
speed compressor)
Compressor 3 (constant-
speed compressor)
If the inverter compressor operating frequency is low, the current value is also low. Therefore this alarm is
detected only when the compressor is stopped.
The operating current of the constant-speed compressors is always higher than 1.5 A. Therefore, this alarm
occurs as the result of an open circuit or failure.
Constant-speed Overload
compressor current [A]
Compressor 2
Compressor 2
Compressor 2
Compressor 2
Compressor 3
Compressor 2
Compressor 3
Compressor 2
Lock
Overcurrent
current
H11 H12
Alarm
H03 Occurs when an open CT circuit is detected in the inverter
compressor.
H13 Occurs when a current value of 1.5 A or less is detected
when the constant-speed compressor is operating.
H23 Occurs when a current value of 1.5 A or less is detected
when the constant-speed compressor is operating.
Description
Description
Lock current
[A]
12.1 13.7
12.7 14.3
12.7 14.3
12.1 13.7
12.1 13.7
12.1 14.3
12.7 14.3
Compressor 3
Lock
Overcurrent
current
H21 H22
Description
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3-WAY SYSTEM
Control Functions