Chiller problem

[Chiller 09]

Hi
I am new to this forum. I am not an engineer but my father’s company are the registered dealer of Mcquay here in Pakistan. Almost about three years ago the company installed two air cooled screw chillers at a GSM company named Mobilink. Couple of months back one of the chillers developed a fault. According to the on sight engineers when they turn on the supply and give the switch on command to the controller all the 6 condenser fans turn on immediately and the compressor itself switches on after a couple of minutes. They say that it is entirely opposite to the normal behaviour of the chiller as the condenser fans take some time to turn on after the compressor is switched on. This operation has caused serious concerns here as we are standing at the door step of winters and this problem results in liquid carry over resulting in icing especially in the winters.

Can anyone help with this particular problem?
One more thing one of the engineers working on the chiller thinks that the controller program has been corrupted. He says that the controller itself was broken once due to an electrical surge or something n after repairing it stopped working.
I will really appreciate of you people can provide any information on this particular problem.

[Grizzly]

Welcome Chiller 09.
From what you tell us.
I would tend to believe the site engineer.
Basically the control stratergy is "Corrupted"
If your father imports these machines.
I assume he has someone capable of maintaining them?
Whoever you get to commision them.
Ask them to investigate this chiller!
Grizzly

[Chiller 09]

Hi Grizzly'

Thanky you for your prompt reply. Yes you are very right about the maintenance engineers. They do have them but frankly speaking they are just drawing salaries from my dad. He had a couple of good engineers but unfortunately both of them went abroad two years ago. Anywayz as u said that in your opinion it looks like control logic problem do you think re-programming the device can solve this issue ? I know u cant be sure as u have to be working on the particular chiller to be sure bt i am jst looking for good solid logical ideas.

Thanks in advance..

[DEVIL]

don't base your self on what somebody else is telling you, it might not be of a profession that is in the direction of chiller behavior.

Probably the chiller is having more then one compressor, and maybe he heard the second compressor go on, but in fact one compressor is already running, or the wind might turn the fans, some one that is not specialized in the domain could tel you all sorts of facts that are explained in all sorts of ways and could be a normal behavior.
You have to go and see for your self all the real facts, that is not the normal behavior , and test all the components that are in relationship with the fans, it might just be a pressure switch, rarely the controller must be reprogrammed, usually it's something else

[baycuclaudyu]

Hi chiller 09 maybe the transducer is decalibrate .The first thing is try to chenge the controler board with the another one and will see if it works .

[MQFS OZ]

Chiller09,

What is the chillers Model No?

This will help us help you.

It could well be a faulty transducer

Regards

MQFS OZ

[Bhagwan Harani]

I think there is nothing wrong. Fan should start first than Compressor.
In water cooled application, first Cooling Tower is ON,than Condenser Pump & than Compressor
Withot fan ON Discharge pressure will shoot & Compressor will trip on HP

[Chiller 09]

Thx baycuclaudyu,

Yes they have used the controller of the second chiller on the first one (Faulty Chiller) and the chiller works perfectly.. on using the controller of the (Faulty Chiller) on the second chiller, it makes the second chiller go crazzy just like the faulty one...

[Chiller 09]

Thx MQFS OZ

Sorry for replyin in so late. The specs are given below;

- Mcquay Air Cooled Single Screw Chiller
(First Generation)
- Model No: MSC 200.2 ST 022-FCE-E
- Carel Microtech II controller
- Controller Code: PCO2000AL0

Is this information enough ? Do let me know if u need anything else.

Thx in advance.

[baycuclaudyu]

With pleasure ,try to copy all the setup on the good control board to paper and all the setup put in to control board with problem .Maybe somthing setup its lost .