Sanyo MDF-394 Service Manual page 25

9. Control of compressor
Differential temperatures
When chamber temp. is set temp. -0.4㷄
When chamber temp. is set temp. -1.6㷄
When H side compressor turns on
and cascade temp. is -34㷄
Interval of H/L compressor ON
*Note) L side compressor turns on only when cascade temperature is reached to -34㷄 after 1
minute elapse since H side compressor was turned on.
<Compressor control during cycle operation>
Chamber temp.
=Set temp. -0.4
Chamber temp
.=䌓et temp.-1.4
Chamber
Temp.
Cascade
temp.
䌈
䌌
H side compressor protection:
H side compressor is turned off to prevent the compressor being warmed up that is caused by
the fan motor locked.
Filter sensor temperature:
The High side compressor is turned off when the filter sensor temperature is equal or higher
than 60㷄. The High side compressor is turned on again when the filter sensor temperature is
equal or lower than ambient temperature +10㷄.
10. Delay time
Compressor delay time (Initial: 3 minutes)
When the compressor seizes during cycle operation, both L/H side compressors restart with
the delay time. You can choose delay time in F05.
Power failure alarm delay time (About 3 seconds, fixed)
When the power is failed, the power failure alarm activates with about 3 seconds of delay.
The delay time is fixed.
: H side compressor turns on.
: Both H/L side compressors turn off.
: L side compressor turns on.
: 1min.
More than1min Chamber temp.
More than 3min
䋨Comp. delay䋩
Chamber temp
.=䌓et temp.-1.4
Cascade
temp.=-34㷄
H/L Comp. OFF L Comp. ON
H Comp.
ON
22
More than1min
=Set temp. -0.䋴
More than 3min
䋨Comp. delay䋩
H/L Comp. OFF
H
ON
Set temp.
Set temp -0.4㷄
䌓et temp.-1.4㷄
Cascade
temp.=-34㷄
Cascade temp
.=-34㷄
ON
OFF
ON
OFF
L Comp. ON
Comp.