YORK YCAM B450 strange PCB problem

[exxu]

The problems i've experienced with this chiller were 2:
1. the pcb won't start the 2nd or 3rd fans, so the chiller gets is HP fault.
2. on one circuit the pcb signals differential oil pressure fault before the compressor is started and locks it down. Wasn't it suppose to start the compressor and then, after 1 or 2 minutes to check if the oil pressure is ok?
I couldn't find any info about the controller or chiller. Can anyone help me?

HAPPY NEW YEAR !

[Grizzly]

The problems i've experienced with this chiller were 2:
1. the pcb won't start the 2nd or 3rd fans, so the chiller gets is HP fault.
2. on one circuit the pcb signals differential oil pressure fault before the compressor is started and locks it down. Wasn't it suppose to start the compressor and then, after 1 or 2 minutes to check if the oil pressure is ok?
I couldn't find any info about the controller or chiller. Can anyone help me?

HAPPY NEW YEAR !

A happy New Year to you Exxu.
My York data is limited but what i have attached may help.
Basically you have to manually reset an oil diff alarm.
Before you can restart that compressor.
I believe the normal fault delay is 120 seconds.
also it may well be due to you oil heater in the compressor crankcase having failed.
The attached details a reset!
I believe the fan run parameters are York set and only programmable with the correct codes.
I will ask a friend about that one?
Anyway I hope the attached helps?
Grizzly

[exxu]

Grizzly,a gentleman as always, thanks for your very fast response.
This chiller worked very well till one week ago (since 2002), then it started to act this way, so the settings are ok.
The oil pressure fault appears ramdomly. Sometimes the compressor starts normally without any faults(so the oil temperature is ok), does his job then stops at setpoint. The oil pressure, when the compressor works , is excellent: about 9 bars. After about 10 minutes, when the chiller needs this compressor to start, the pcb emits the oil pressure fault before the compressor even strarts and locks it down.
When i tried to reset the alarm i couldn't do that unless i switched off, then on, the circuit from the panel by pressing the "Circ2" button, then the normal procedure for resetting alarms.
The fans are not started regardless the condensing pressure, or the circuit that is started: it works with only 1 fan/ circuit till it "dies" in high pressure alarm.
For now i connected the comand signal from all 3 fans toghether and the chiller runs fine: HP=15 bar, LP=4,5 bar, R407C, OutTemp=-5C.
I suspect the PCB is defective.

[Grizzly]

I suspect the PCB is defective

.

With the updated information you have given us.
I suspect you may be correct.
It is the random bit that gives me the problem.
Maybe some of the other lads have an idea?
Meanwhile I will see what I can find out.
Grizzly

[narkom]

You should check the line from the oil pump to the HP side of the oil pressure diff. pressostat. If it is a capillary tube it may be blocked. So than the compressor stops the oil pressure in this line decrease very slowly and the contact of the oil pressure diff. press. remains closed for a long time. Than it is time to start the compressor the corresponding PCB dig. input is still closed and PCB emits the oil pressure fault.
All above is not only the theory this is from my YORK experience.

[al]

The condenser fans are controlled by liquid line temperature rather than pressure,the probe is clamped on the pipe behind the compressor.

On previous units we have fitted hp switches to control the fans, but check refrigerant charge is ok and that the liquid line drier isn't restricting flow.

al

[exxu]

Sorry for the delayed post but York parts are very hard to get here.
Indeed the problem was the PCB. It was changed with a new one and the problems dissapeared. Magic!


"The condenser fans are controlled by liquid line temperature rather than pressure,the probe is clamped on the pipe behind the compressor."
The condenser fans are "controlled" by the outside air temperature.
The 1st group of fans is energised whenever a compressor is on.
In the service menu you can chose the temperatures that inhibits the 2nd and 3rd groups of fans. Default are 10 and 0 Celsius.
Still, i think that this chiller has another problem:
at -2 C it needs two group of fans(out of 3) to keep the high pressure below 20Bar, so it seems that the refrigeration circuit contains noncondensables.
Thank you very much for all the responses, especially Grizzly.
Keep in touch.