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Compressor running control
1.) In cooling mode, when RT≤T (cooling)
-0.5
℃
,
compressor runs with minimum frequency.
When RT≤T
(cooling)-1.5
℃
,
after running for 120 seconds with minimum frequency, compressor is switched off.
When ST≤7
℃
The compressor runs with minimum frequency.
When ST≥8
℃
.
The compressor runs with normal PID control.
2.) In heating mode, when
RT≥T(heating)
+0.5
℃
, compressor runs with minimum frequency.
When RT≥T(heating)
+2
℃
,
after running for 120 seconds with minimum frequency, compressor is switched off.
3.)
Compressor running frequency is adjusted in every SF19 time.
The first time compressor is switched on for heating or cooling, it runs 2 minutes with 45Hz and then runs with PID control.
When the compressor is switched on again from a standby state, it runs with minimum frequency for 2 minutes and then
runs with PID control.
4
.) DHW running
The compressor runs with outlet water PID control with ST21 as control target.
In DHW operation
, when ST≥ST21+1
℃
, the compressor runs with min. frequency.
5.)
Oil return running
1.) If the accumulated compressor running time is over 120 minutes with a running frequency lower than 40Hz or higher than
60Hz, an oil return running is activated. On the compressor running accumulated counting process, if compressor running
frequency is over 40Hz or lower than 60Hz for a continual 2 minutes, the accumulated counting data is reset to 0 and
accumulated counting starts again.
2.) Oil return running process: Compressor runs 60 seconds with running frequency 50Hz and then returns to previous
running frequency. During this process and within 60 seconds from the end of this process, circulation pump runs with EV05
PWM speed. During this process, if low outlet water temperature protection or high outlet water temperature protection
alarm is activated, the compressor is switched off but this alarm does not display on user interface.
7.)
High frequency running limit
After the first time switching on, if the compressor runs with the maximum running frequency for over 30 minutes, the
running frequency will be limited to lower than rated running frequency for the next 30 minutes.
Except in the conditions below, it will not run with frequency higher than rated.
⚫
Re-start after power cut out and cut in again.
⚫
Switching on from off state
⚫
switching on from stop state after a fault
8.)
Reduced running frequency to protect the compressor.
A.) pressure protection
When system pressure is higher than 36Bar for over 5 seconds, the compressor running frequency reduces by 10Hz, after10
seconds:
a.) If the system pressure is still higher than 36Bar for a further 5 seconds, the compressor running frequency reduces by a
further 10Hz - and so on until the system pressure is no longer higher than 36Bar for a continual 5 seconds.
b.) If system pressure is lower than 36Bar after a continual 5 seconds, it keeps current running frequency. Until system
pressure reduces to lower than 34Bar for a continual 5 seconds, then it will restore to PID control running.
If the compressor running frequency reduces to 40Hz and system pressure is not higher than 38Bar, compressor runs with
40Hz. If system pressure still goes up to over the alarm setting limit for a continual 5 seconds, the compressor is switched off
and is re-switched on after a 3 minute' delay.
B.) Discharge gas temperature protection
If Discharge gas temperature PT ≥100
℃
for a continual 5 seconds
,
the compressor running frequency reduces 10Hz in every
10 seconds until PT≤95
℃
for a continual 5 seconds, then compressor running speed will store to PID
control
.
C.) IPM module temperature protection.
If IPM module temperature≥80
℃
for a continual 5 seconds
,
the compressor running frequency will be reduced by 10Hz
every 10 seconds until PT≤75
℃
for a continual 5 seconds, then compressor running speed will store to PID control.
D.) Compression ratio protection
After the compressor has run 10 minutes, if the compression ratio ((HPS+1Bar)/(LPS+1Bar
)
is more than 8 in a continual 5
seconds, the compressor running frequency will reduce 10Hz , 10 seconds later:
1.) If compression ratio is no more than 8 for a continual 5 seconds, it keeps the current running frequency.
2.) If compression ratio is still more than 8 in continual 5 seconds, the compressor running frequency reduces 10Hz more and
so on until compression ratio is no more than 8 for a continual 5 seconds. then it keeps current running frequency.
If the compression ratio is less than 7 over a continual 5 seconds, it will restore to PID control speed running
.
CONTINUED