Chiller Carrier 30GXR301...

[Jubilee]

Hello every ones it is my first post and i'm a french speaking guy, so...
We having a lot of problem with our Hvac system since a long time. Almost 3 years ago, a tech. came over while we were in Rotterdam getting ready to work in Angola. NB: I am on an oil rig. Any way , the guy change filters and been new on the rig and quit busy at the time. i did not have any question then.
We worked in Africa and keep the place cool enough. But for a long time all 4 compressors are going steady. I am not use to that type of system, but i beleive the heat exchange ratio is no long efficient, there is about 2 deg. f. in differential across the evaporator, it is about the same across the air handler coil. I would like to now if it is sufficient and it is the way it should be, or if not how can we resolve that problem. Also i should say the system shotdown on low saturated suction pressure, we tought a leak low in gas and add some and add some more and... Something is wrong somewhere.
Thanks to whoever can translate that.

[james10]

low sst can be a result of a faulty expansion valve you can check the valve opening percentage in the outputs menu if prodialog or anolouge outputs if hsio control if the valve is 100% open you need to make sure it is opening/closing on system startup hold a screw driver to the body of the valve the other end on your ear (this works honestly) you should be able to hear the valve modulating also check cable conections either end and that you are getting outputs from the exv driver board also check the transducer attach gauges and compare reading to the controller if all is right you need to weigh out the refrigerant charge if low preesure test unit repair leak and evacuate and recharge to the unit name plate

[Jubilee]

Hi James 10, thank for the reply.
I checked the expansion valve output signal on the display before it show a modulated output percentage which look like to be right according to suction pressure change.
What do you think about a "poor" heat transfert in the evaporator?

Thank you again, i will re-check the EXV as explained.

And looking forward for your advise.

Bye.
You are in North East England? Don't feel for a ride in Scotland in Dundee neighborhoody by any chance.

Just joking...

[james10]

sorry i should have said low cooling accross the evap could be caused by exesive water flow accross the evap or blocked tubes you need to work out the flow rate take the inlet and outlet chilled water pressures accross the evap with the pumps running if you post the full unit details along with your readings i can work this out for you if the evap is dirty it's time to take the end plates off and rod the tubes which is a ball breaking task also if you have added refrigerant and the unit was not low you will need to recover and weigh in the correct charge as an overcharged system will cause even more problems be carefull with the oil though these units are very tempremental with oil levels
Dundde why not the weathers good up north

[Jubilee]

Hy! We are very fortunate that you take the time to help us.
I will pass it on to my colleague.
Also, “they” as the management, are suppose to arrange a meeting with a refrigeration firm, to get that thing repaired but I do not know where they are with that, probably not far because we managed to cool the quarter down, so it is all OK now...
Then if you or somebody than you know are interested to do business I can submit the company name, does not cost anything to try. We got few other unit to be service also, fridge, a/c, walk in cooler all kind of fun.

Any way thanks’ again for the information.
Bye

[james10]

check your inbox

[Gibbo]

From my experience with oil rigs off Africa including Angola there won't be any PPM getting done and even if you get a refrigeration company to look at your chiller it is highly unlikely they will be familar with this type of chiller control system.
Would recommend you get the local Carrier office to send a engineer to take a look. As its critical for your accomadation to remain cool due it being pressurised this is something you can't do DIY.

Good Luck

Gibbo