SiBE04-101
General Functions
Main Function
39
1.18
Compressor Protection Function
Outline
An refrigeration oil level descent and progression of the dilution which will arise at operation of the
compressors will be avoided by controlling the upper limit of frequency at the edge of compressor’s
changeover from OFF to ON as follows.
Processing
1. Frequency control
Set the upper limit of the operation frequency by the controls as follows:
In starting of compressor, start the timer TCG1 and set the upper limit of output frequency at TCG2 for
the time of TCG1.
When the time of TCG1 expires, start TCG2 timer and set the upper limit of output frequency at TCG2
for the time of TCG2.
When the time of TCG2 expires, start TCG3 timer and set the upper limit of output frequency at TCG3
for the time of TCG3.
When the time of TCG3 expires, reset the limit of frequency.
2. Others
When the compressor operation is stopped at the time of starting this function, reset the timer which is
counting and reset the limit of frequency.
These controls are not necessary during defrost control.
∗
FCG : Frequency guard for compressor protection
∗
TCG : Timer guard for compressor protection
50 Class
60 Class
71 Class
FCG1
58 Hz
42 Hz
32 Hz
FCG2
64 Hz
64 Hz
64 Hz
FCG3
74 Hz
74 Hz
74 Hz
TCG1
120 sec
120 sec
120 sec
TCG2
240 sec
240 sec
240 sec
TCG3
240 sec
240 sec
240 sec
T CG3
T CG2
T CG1
Compressor operation frequency
time
F CG1
F CG2
F CG3
Compressor ON
(R1043)
SiBE04-101.book Page 39 Monday, October 15, 2001 3:08 PM
