PDA

View Full Version : Oil flow switch Trip







ArmghanAlvi
31-03-2016, 12:57 PM
Dear all,

I am facing a problem with Bitzer Screw Compressor HSK8561 -125 oil flow switch & Protection Module SE.E2, as when ever we try to start the compressor it trip from two side one from Oil & the other from the module.
That module protect three things phase sequence, rotation & PTC. Phase sequence & Rotation are fine but we have doubt on PTC ( temperature).

Any idea to solve this problem.

Thanks
Armo

Goober
31-03-2016, 11:50 PM
IS this inverter driven?

Magoo
01-04-2016, 03:10 AM
I would suspect the oil pressure sensor , to test , bridge out oil sensor circuit as a test run only. If on a VSD as per goobers comment the minimum hertz is around 30 Hertz to maintain oil pressure at start up if a new system

Tycho
01-04-2016, 05:48 PM
Dear all,

I am facing a problem with Bitzer Screw Compressor HSK8561 -125 oil flow switch & Protection Module SE.E2, as when ever we try to start the compressor it trip from two side one from Oil & the other from the module.
That module protect three things phase sequence, rotation & PTC. Phase sequence & Rotation are fine but we have doubt on PTC ( temperature).

Any idea to solve this problem.

Thanks
Armo

Hi Armo, Welcome to RE :)

First, in case you don't have it, here is the user manual for the SE-E2 controller :)
https://www.bitzer.de/shared_media/documentation/st-122-1.pdf


If I understand you correctly, it trips from both the SE-E2 and the oil flow switch at the same time? does the compressor start at all, or does it go to alarm instantly when you push the start button?

1. Does the compressor start at all, or does it go to alarm the instant you push start?
2. when it goes to alarm, do the oil flow and SE-E2 alarm come on at the same time? (is the oil alarm coming a few seconds later??
3. is the compressor starter star/delta or frequency drive/soft starter?
4. is the oil flow switch connected in the same circuit as the SE-E2?
5. is there a delay timer on the oil flow switch?


it would be helpful if you could post a picture of the circuit diagram showing how it is wired, I could probably make a more educated guess, but here goes:

-First thing I would do would be to disconnect the wires and measure the PTC.
From the user manual:
PTC Switching point:
Relay off (alarm) if resistance is above 11,4 kΩ +/- 20%
Relay on (normal) if resistance is below 2,95 kΩ +/- 20%

if the PTC is ok according to the resistances, the next ting I would do is to put a jumper/bridge on the wires going to the PTC connections on the SE-E2 (terminal 1 & 2) and push start to see if the compressor starts...

if it starts and keeps running, the SE-E2 is broken (if the SE-E2 is of the same quality as the Kriwan INT69, there is a 70% chance that it is the protection unit that is broken).

If the oil flow switch has a delay timer, this should be set to 15-20 seconds.

if the compressor has a frequency drive/soft starter, make sure the starting ramp time is not too long, no more than 15 seconds, 10 seconds is better if it
(if frequency drive or soft starter, make sure that the delay on the oil flow switch is at least 5 seconds longer than the start ramping time)

Lots of guessing here, if you could provide more information especially let us know if the compressor is on a frequency drive, or a star/delta contactor starter, and also if you could show us the control current wiring diagram of how the SE-E2 and oil flow switch is connected it will be a lot easier for us to help you :)