Chiller fault

Couldn't decide whether to post this thread here or in air conditioning section so did both

York chiller, dreaded fault code-the usual LOW CURR/MP/HP. Chiller doesn't start on the problem circuit, just a couple of clicks and out on the fault, maybe after about 5 seconds. I thought it must have been the mecahnical HP switch when I got there, so had a look, but it had't tripped (pressed the reset but it was already in). Now usually I would have thought that a motor protection fault would not still be there as the compressor (a screw one) was not hot. If there had been another problem I had expected the chiller to start up for at least a few seconds before any current faults could have been detected, so as no current was ever drawn as the contactor never pulled in, I think perhaps the HP switch must have an open circuit fault.

HELP please.
Thanks
James

PS I was only asked to look on way home so due to time being a bit short was only there 30 minutes and then we had a thunderstorm.

Hi James, A few years ago we had a York Chiller that had to be reset everyday with the types of faults that you are seeming to get> One of my service guys came and said i dont no what happened. Anyway i went to the buiding in late afternoon looked around and discovered that the make up water in cooling tower couldn`t keep up with the water being evaporated, low and behold all it took was to open the make up water to full open and let the let the float valve control it. That was the cure no more nuisence calls

regards Toosh

:) Its the auxiliary contacts on the top of contactor, it will fire in star and when she changes over it fails. Had loads of them go on me Trane have the same problem with Abb contactors, if its not the top set then try the cal5 at the sides they play up. Abb have changed them to cal18 i think. ;)

james

There are two hp in series, one may have water in or may just be faulty, link it out and try again. if you had a current or motor failure the module would be flashing a code.

Alec

:eek: I have changed many auxillary contacts on York chillers. The ABB auxillaries are very crudely made and fall apart at the drop of a hat.:mad:

The fault shows up as a motor overload fault and can deceive you into looking for a motor fault or HP

Thanks Guys

It doesn't even start in star, the motor pulls nothing. After 5 seconds it flashes the fault on the panel. Theres no code on the blac box just flashes HA084, which I think is the setting for current.

So because it doesn't actually start or try to, that's why I think it's the HP. The mechanical one doesn't seem to have tripped, the primary transducer I think might be the problem, or the machanical switch perhaps has an open circuit. All will be revealed next week.

Thanks again Alec (this isn't the same as the last chiller)

Cheers
James

Hi Theres a control relay board sometimes located in the motor terminal box or in the panel depends which model of chiller but this is most likely to be at fault assuming you have checked HP wiring

Charlie

Quote:

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Originally Posted by iceman007

Couldn't decide whether to post this thread here or in air conditioning section so did both

York chiller, dreaded fault code-the usual LOW CURR/MP/HP. Chiller doesn't start on the problem circuit, just a couple of clicks and out on the fault, maybe after about 5 seconds. I thought it must have been the mecahnical HP switch when I got there, so had a look, but it had't tripped (pressed the reset but it was already in). Now usually I would have thought that a motor protection fault would not still be there as the compressor (a screw one) was not hot. If there had been another problem I had expected the chiller to start up for at least a few seconds before any current faults could have been detected, so as no current was ever drawn as the contactor never pulled in, I think perhaps the HP switch must have an open circuit fault.

HELP please.
Thanks
James

PS I was only asked to look on way home so due to time being a bit short was only there 30 minutes and then we had a thunderstorm.

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James
Is this chiller microcontrolled.If it is microconrolled pls check transformer ratio
Thanks

Check wether the MCB installed for the Compressor Circuit is ON. If it has tripped the Circuit will trip indicating the fault. YORK chillers have a HP Switch installed at the compressor, try to reset that switch too or check wether it is stuck Open. If nothing else works check the I/O board for that particular circuit.

All the best