Defrosting Operation - Technibel GRV79R5VAA Technical Data & Service Manual

8-7. Defrosting Operation (Heating)
Defrosting Flowchart
Release of overload prevention
(Outdoor fan operates.)
A
Outdoor fan is either operated
or stopped for more than 10
minutes.
Is outdoor fan continuously
NO
operating for more than 10
minutes?
YES
Integrated operating time of
compressor is more than 50
minutes.
Temperature of indoor heat
exchanger coil is below Ta+
13°C . (See table below.)
Compressor keeps running for
at least 6 minutes.
NOTE
The values shown as Ta, Tb and Tc
differ according to the models.
MCAV77
*1 Ta 35
*2 Tb 48
*3 Tc 32
Overload
YES
prevention works.
Does outdoor fan
stop?
NO
B
Indoor heat exchanger coil
temperature drops 0.8°C per
6 minutes and it repeats
3 times in succession.
*1
Continuous operating time of
compressor is more than 20
minutes.
Temperature of outdoor heat
exchange coil is higher than
12°C.
MCAV97 MCAV127
38 44
51 57
33 34
Compressor ON
C
Integrated operating time of
compressor is more than
3 hours.
Temperature of indoor heat
exchanger coil is below Ta°C .
Compressor keeps running
for at least 6 minutes.
Temperature of outdoor heat
exchanger coil is below 9°C.
Defrosting begins.
Cold-draft prevention
Defrosting time is over 12
minutes.
Release of defrosting
*3
Indoor fan runs at set speed
when temperature of indoor
heat exchanger reads Tc °C.
49
D
Integrated operating time of
compressor is more than 1.5
hours.
*1
Thermo. OFF.
(Compressor OFF)
Temp. of indoor heat exch.
coil immediately before thermo
goes off is either below
Ta + 4°C or Tb + 4°C (when
overload prevention works).
NO
Compressor keeps running for
at least 6 minutes.
NOTE
No LL fan operation during this period.
*1 & *2
YES