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Copyright ©2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Part 3 Control logic
5.1 Function
Controlling total current to protect power semiconductor devices from burn-out by the low current (including connecting
mistake) and over current.
Operating process
1. Detection : check the output DC voltage of Current Transformer(CT).
5.2 Operating process
CT 1 detection :
1) If total current exceeds CT1+1 value, reduce inverter operation by 1 step.
- Step down 5Hz(Option) from current step.
- If new Hz is below minimum Hz of operation (cooling & heating), then turn off the compressor.
2) After step down, still if the total current exceed CT1 for more than 5 sec.
then step down inverter operation by 1 more step.
3) If the current continue below CT1 for more than 1 min., return the to setting step Hz.
CT 2 detection :
1) If total current exceeds CT2 turn off compressor.
And after 3 min turn on the compressor and check the current again.
2) If CT2 occurs 5 times in 1 hour,stop the operation and shows Self-Diagnosis Error Mode 22
5. Input Current Control
Current(CT)
Frequency
[Hz]
Setting
frequency
Frequency
fixed
5 Hz
(Option)
Down
Frequency
fixed
Setting
frequency
Frequency
fixed
5 Hz
(Option)
Down
OFF
CT2
CT1+1
CT1
Summary of Contents for FM15AH UL3
Page 136: ...P NO MFL36552501 JUNE 2008 ...
