LG Multi-Inverter Type - 7. Defrost Control

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Only for training and service purposes
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Part 3 Control logic
7.1 Function
:These are about the control of compressor, fan of outdoor unit, reversing valve, LEV.
7.2 Starting to the defrosting operation
A) Defrost operation will be start when all the conditions below are matched simultaneously
Accumulation time of operation and the period after completion of defrost = 35min (Outdoor air temperature –3˚C)
B) Outdoor piping temperature is below than –6 (Option)˚C for starting defrosting operation.
7.3 Completion of defrost operation
Send signal of defrost completion in case of meeting one of the condition as below.
1. Defrosting time 7 minutes
2. Piping temperature maintain 10 seconds (Option ) in condition of more than 15˚C (Option).
7.4 Defrosting Control Algorithm
7. Defrost Control
Inverter Comp.
Outdoor Fan
Outdoor LEV
Indoor Fan
Reversing Valve
Satisfy
Defrost
Start
Condition
Satisfy
Defrost
End
Condition
Defrost
Start
Heating
Start
(Defrost flag clear)
80 Hz (Option)
Control
ON
OFF
ON/OFF
ON
OFF
ON
Control
350 Pulse
(Option)
OFF
Hot
start
1 2 3 4 5 6 7 8 9
Defrost signal of
indoor unit on/
Starting maximum defrosting
time count
Indoor defrost signal OFF
10
Baseline