Bosch HP270-2 - Status Diagram for Gas Defrost Procedure

Page 13 from 56 6-720-821-364 SM HP270 – 250 - 200 2016/12 en
Conditions for gas-defrost sequence:
Gas Defrost sequence is activated only in -10ºC / +35ºC models when -10ºC < T
air
< 5ºC for more than 60 min,
performed in 2 steps (Pre-gas defrost + Gas defrost), according to the compressor operation conditions.
Or
or
Pict.10 – Status diagram for gas defrost procedure
1
st
step: Pre-Gas Defrost
2
nd
step: Gas Defrost
Fan ON
Fan OFF
Solenoid
ON
Compressor
ON
Compressor
ON
Time for pre-gas defrost (HP270-2):
T
bottom
< 25ºC / Time = 2 min
T
bottom
> 25ºC and < 40ºC / Time = 1 min
T
bottom
> 40ºC / Time = 0.5 min
Gas Defrost sequence stops when
T
fins
> 6ºC or gas defrost lasts for
more than 30 min
Condition 1:
Compressor is ON for more than 180 min
Condition 2.1:
Compressor is ON for more than 60 min and
T
air
-T
fins
> 3.5ºC for more than 1 min
Solenoid
OFF
Condition 2.2:
Compressor is ON for more than 60 min and
T fins < -17ºC or compressor stopped for some
reason
OFF
OFF
Time for pre-gas defrost (HP270-3):
T
discharge
< 25ºC / Time = 2 min
T
discharge
> 25ºC and < 40ºC / Time = 1 min
T
discharge
> 40ºC / Time = 0.5 min