TMC 54-85 EANA internal pressure issue

Question Title: TMC 54-85 EANA internal pressure issue
Asked by: Bogdan
Asked On:
Answers: 2

Hi,
I would appreciate an advice if possible.
On screw compressor TMC 54-80 EANA , when loading cycle finishes the compressor is doing a stand by run program of 200 seconds without producing air pressure. When this program ends, blow down 10 second phase occurs.
My problem appears when air demand is high and the compressor has to begin a new cycle but internal pressure is still high, about 6.2 bar. Brief RUN INHIBIT alarm occurs and after 3-4 seconds clears and new cycle begin.
I'm wondering why the internal pressure is not drained faster , where the obstruction can be?!
If 200 sec program ends and blow down phase appears, I have no issues, the compressor stops with 0 bars pressure and restarts without any problem. The alarm came only in high air demand moments due to "high internal pressure'' RUN INHIBIT alarm.

Thank you.

Answers & Replies

Cas

5 years ago

Hi Bogdan,

So it happens when the compressor wants to re-start in that 10 second window of blow-down?

Yes, it's probably just bad-luck, but annoying. It looks like the compressor waits for a few second and then tries again?

That all sounds normal. It is a protection programmed into the controller to protect the electro motor, because the load will be too high if the compressors starts when there's still pressure inside.

You can try to make the blow-off faster by making the blow-off hole bigger (it depends, sometimes you need to change all tubing and solenoid valve) - but 10 seconds blow-off is pretty OK.

Maybe your air usage is precisely so that after 200 seconds of unload running, it reaches the lower pressure setpoint - but the compressor has just stopped at the time.

So you could try to make the unload run time a bit shorter or longer - or change the pressure setpoints a bit.

Hope this helps :)

Cas

bakov

4 years ago

Hi,

i have same problem as Bogdan does, but when I try to change st-by run timer, new value is shown on compressor panel, i have Smart Pilot, but the compressor stops after 200 seconds, whatever the setting for st-by run is. In my situation i changed st-by run timer to 300 secs, but the compressor stops after 200s eventhough it is counting down from 300s on panel screen. compressor is connected and controlled by kongsberg. Remote start, load and un load and remote stop. Thank you

Bakov