Service Manual

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6. Defrost control

In heating operation, defrost operation is performed when TE sensor temperature satisfies any condition
in A zone to C zone.

The defrost operation is immediately finished if TE sensor temperature has become 12°C or more, or it
also is finished when condition of 5°C < TE < 12°C has continued for 80 seconds.
The defrost operation is also finished when defrost operation has continued for 15 minutes even if TE
sensor temperature has become 5°C or lower.

After defrost operation has finished, the compressor and the outdoor fan start heating operation after
stopped for approx. 40 seconds.
Start of heating operation
0 10 15 29 35 [min.]
*
TE [˚C]
–4
–6
–10
–25
A z
A z
one
one
C z
C z
one
one
D z
D z
one
one
A zone
C zone
B z
B z
one
one
B zone
∗ The minimum TE value between 10 and 15 minutes after heating operation has started is stored in memory
as TE0.
A zone
B zone
C zone
Defrost operation is performed in this zone when TE0-TE > 2.5 continued for 20 seconds.
Defrost operation is performed in this zone when TE0-TE > 3 continued for 20 seconds.
Defrost operation is performed when this zone continued for 20 seconds.