York screw chiller fault

[Stretch79]

Hi guys

Did look through here for an answer but was nothing definitive.

Am at a call out for the above chiller which has gone into fault on circuit 1, current/MP/HPX and C2 has gone out on low suction.

Have checked fridge pressures and all seem ok, overload led on opto board is illuminated, starting current of comp is 141amps, according to the system display oil pressure is ok too.

Being it’s hot and I’m in London atm with temps of say 30 would the oil be an issue? The comps are old and have a few leaks, top end a bit rattly also.

So scratching my head really. C1 starts up, goes delta then star and literally 2 seconds later goes into fault and ar timer starts.

Anyone had any joy or similar issues with these?

Thanks in advance

[Sserrviceman]

Maybe it is necessary to reset high pressure cut-out switch?

[Stretch79]

Hi there.

No that’s been done. Hadn’t tripped

[al]

What model chiller is it? Is the compressor actually starting up on C1, are amps ok? Will C2 reset and run or is it still tripping on low suction?

[Stretch79]

Hi guys.

Will have to get model tomorrow sorry.

The comp starts up. Star contractor kicks ioffvn then delta. Literally when delta kicks in a second later trips out. I clamp metered star and inrush current of 141amps on L1. Literally no time to test much due to tripping.

Circuit 2 eventually ran after a few resets however believe this circuit has a leak and needs a full leak test etc, but again reaching set point goes into suction fault again

Would it be a bad assumption for maybe seizing compressor?
It’s an odd one and puzzling me.

[Sserrviceman]

What type of compressor and motor protection module? I know this alarm is a typical problem with some Texas Instruments Klixons. Just make sure you thigh up the connection and also inside the compressor junction box, clean the connections because oxidation and humidity can cause this troubles.

[Stretch79]

Hi service.

Yeah it’s the same as your picture. However it seems pretty clean but it’ll be worth a shot doing as you’ve said.

So you thinking it’s a possible electrical issue somewhere then?

[Brian_UK]

Is the star/delta timer working correctly?

Try C1 and C2 without power to the compressors, do they both time out the same?

[al]

With some of the earlier screw chillers there was an issue with the aux contacts on the ABB contactors bouncing on transition to delta which led the system to believe that one of the contactors had dropped, exact same symptoms, your current looks ok for inrush, does it sound ok?

[Stretch79]

Just an update after the advice...

We found a contractor on the delta side to have failed. The coil looked to have been fried. Replaced the contractor and works well now and fixed the leak.

However. Now circuit 1 seems to be having issues. Fix one thing another comes up eh..

Circuit 1 will run for about 5 or so minutes give and take then just pop out and goes through ar timer again.

I’m looking into it but it’s a mare as you can imaine. Believe it to be electrical still, possibly something warming up then popping out into fault.

No warning comes up on display so I can’t tell what it is

Any ideas on this one as scratching my head.

Going to check solenoid coils, contractors and know the motor protection module is ok. Swapped this other and no issues transfered across.

Thanks

[Stretch79]

Further to this it was running about 10 mins which is the longest yet I only messed with the little pcb board in he compressor housing controlling the coils etc

Goes through the ar timer and resets and starts again. So I’m thinking a coil somewhere surely