Mcquay Cond press high alarm

I am working on some mcquay heat pumps but in one of them i am having a problem from some days. In cooling mode all is ok they newer got problems they are air cooled . One of them is having problems in heating mode and give ' Cond press high' alarm . This is a 2 circuit model i have switch off 1 circuit and run the other 1 and the error was the same. I have checked the circulation water pumps and they are ok water flow is ok. Both compressors run for 10 minutes but when they try to increase stage and speed compressor discharge goes 78-80 degrees celcius and compresor suction line temp is about 11 degrees. Water enter 42 degress in condenser and leave 44. It is near to stop for set point temp 45 but nothing it goes in alarm.

I think maybe is a problem with the transducer but the problem happened with both compressors is possible they use only 1 transducer on condenser?

Sorry for my bad english, Can anyone help?

As the alarm you are experiencing is a pressure one, the starting point for any troubleshooting is to fit a pair of gauges and get a thermometer out.

What is your HP?
LP?
Superheat?
Subcooling?

What refrigerant is used?

Questions, questions, questions...


:cool:

.

i wonder if any one can tell me where to find some information regarding gravity refrigeration . if there is any site to get info.

Best
moe

Attachment 9756Attachment 9757Attachment 9758

i am working on mcquay McEnergy HPI Extension Air to water heat pumps R134a like this http://www.mcquayeurope.com/en/index/prodotti/4/5

The attached photos was taken from 1 circuit during normal run in heat mode than after 3 min it goes in alarm

At 45 % of load after 5 minutes of normal work Hp is 20 bar condenser pressure is 18 bar and when compressor increase stage it goes in alarm for high preassure alarm on board and Cond Press High on BMS software. Sometimes intervent the mechanical preassure switch wich means that the preassure is real and not a problem of any probe who read wrong values.

I don`t remember Low pressure

With the risk of repeating myself...

As the alarm you are experiencing is a pressure one, the starting point for any troubleshooting is to fit a pair of gauges and get a thermometer out.

What is your HP?
LP?
Superheat?
Subcooling?

What refrigerant is used?

Questions, questions, questions...


:cool:


Pressures are useless without temperatures, pressures and temperatures are useless without knowing what refrigerant we are talking about.

One small reflection, 2 bar differential between HP and CP? That is an awful lot...


.

i have upload a video of heat pump, 3 min after when increase stage up condenser press goes 18 bar and it stops for high press alarm. The link of video is : http://www.youtube.com/watch?v=Cmspt...ature=youtu.be

R134a is the refrigerant

Nice video.

Yes the chiller trip out.

I wish you the best of luck and fortune and hope you will find the reason for it tripping soonest.

:cool:

.

Check subcooling in cool mode ...may you have an overcharge system !!!

Hi,

Can you check Relay R-13 or 14 Exactly not remember which is the related to mechanical High pressure switch.