Protection Control; Protection Control For All Operations - Panasonic WH-MHF12G9E8 Service Manual

13. Protection Control

13.1 Protection Control for All Operations

13.1.1 Time Delay Safety Control
1 The compressor will not start for three minutes after stop of operation.
13.1.2 30 Seconds Forced Operation
1 Once the compressor starts operation, it will not stop its operation for 30 seconds.
2 However, it can be stopped using control panel at indoor unit.
13.1.3 Total Running Current Control
1 When the outdoor running current exceeds X value, the compressor frequency will decrease.
2 If the outdoor running current does not exceed X value, the compressor frequency will return to normal
operating frequency.
3 If the outdoor running current continue to increase till exceed Y value, compressor will stop, and if this occurs
3 times within 20 minutes, system will stop operation and OFF/ON control panel LED will blink (F16 error
occurs).
Operation Mode
Heating
A. DC Peak Current Control
1 When the current to IPM exceeds set value of 34 A, compressor will stop. Compressor will restart after three
minutes.
2 If the set value exceeds again for more than 30 seconds after the compressor restarts, operation will restart
after two minutes.
3 If the set value exceeds again for within 30 seconds after the compressor restarts, operation will restart after
one minute. If this condition repeats continuously for seven times, system will stop operation and OFF/ON
control panel LED will blink (F23 error occurs).
13.1.4 Compressor Overheating Prevention Control

The compressor operating frequency is regulated in accordance to compressor tank temperature as shown in
below figures. When the compressor tank temperature exceeds 107°C, compressor will stop, and if this occurs 4
times within 30 minutes, system will stop operation and OFF/ON control panel LED will blink (F20 error occurs).
13.1.5 Low Frequency Protection Control 1

When the compressor continuously operates at frequency lower than 21 Hz for 240 minutes, the operation
frequency will change to 20 Hz for 2 minutes.
MHF09G3E8
X (A)
9.4
Compressor = OFF
112°C
Compressor
Frequency Reduced
110°C
Compressor
Frequency Maintain
108°C
Compressor tank temperature
76
Y (A) X (A)
11.8 10.0
97°C
97°C
97°C
Free
MHF12G9E8
Y (A)
11.8