Carel PCOB

[tes.tech]

Has any body experienced random alarms with Carel PCOB 000 A21 ?
The board is in a Thermocold Water Chiller , 2003 , Twin compressor, water cooled condensor.
The fault = High Pressure Circuit 1, but it only shows after the compressor 1 has cycled off on set point.
I have checked all the interlocks, I suspected the thermistor as this is in the line but its ok.
The I/O doesnt show a fault at any time, I spoke with Carel Technical Support who suggested problem with the memory chip, and resetting all parameters ( can do in manufacture section)
would solve the issue.
Has any body tried this successfully ?
I have to travel along way to re visit machine and would feel better if I thought it may work.
I am currently quoting customer to upgrade controller but would be shame if a simple reset did the trick.

[behzad]

Hi
HP1 is just a digital input, problem is either the HP switch or probably a relay inside your electric panel , all digital input on PCOB are 24Vac, you should have relay between your HP switch and PCOB, check that one first.

Regards,
Behzad

[goshen]

Hi
check wiring, it would seem if this only happens when cycling off.
then some contact is wrong or loose.
good luck

[Hvatit]

I have the same problem. AL013 High Pressure Circuit 2(Thermocold AWA ANERSAVE II 2310 ZC SE B; R407; PCO1 Carel controller). The wiring is OK. Pressure relays: Johnson controls P100CP-1 CO 300Psi(20 Bar) CI 400(27 Bar) with automatic reset. The pressure in the system 2 is 7.5 Bar but relay is closed(it should be closed if the pressure rise 27 bar). Thus the problem is in pressure relay maybe