Mcquay Chiller problem

[mattblade]

hi all, we arrived on site to find a mcquay air cooled wated chiller with the alarm transition or state alarm on both compressors, I don't have the model numbers to hand just wonderd if any 1 could shed any light on the problem ??? contacted Daikin but they don't support the model...

Cheers Matt

[GHAZ]

Hi matt which mcquay chillers are they screw als with soft starter

[mattblade]

Hi matt which mcquay chillers are they screw als with soft starter

hi, theres 2 large screws, on 134a 20kgs in each, 2 circuits, i dont thinknit has soft start on, im going back in the morning so ill check then

[RusBuka]

One-screw McQuay, oil everywhere?

[mattblade]

no 2 screws, have same fault, i forgot to say that both compressors are extremely hot aswell but it comes up with the transition or state alarm for both comps

[mattblade]

solid state sorry

[FreezerGeezer]

I'm not familiar with the brand, but since you say both comp's are extremely hot, & given the alarm message, I'm guessing that they are failing to transition from Star to Delta.
I'd be checking power, megger-ing the motors, checking the power train & if no obvious faults, try a dry start - ie. remove the compressor fuses & put it through the start sequence to see what happens.

[RusBuka]

May be its only electric heater.
I dont understand, you try to start chiller, whats happens? Or its in stand-by mode

[mattblade]

it wont start, goes to start up and alarms out, how ever it did it to 1 circuit not 2 yesterday

[FreezerGeezer]

Did you try what I suggested?
With the equipment I'm familiar with, having removed the Comp. power fuses you can do a dry start - a simulated start, if you prefer. The star/delta contactors & transition resistor bank will still cycle as per design (or as they left the factory) as they aren't dependant on the compressor power.
It was a normal step in the commissioning process, to be sure that the timers were correctly set & all the switching worked as required without endangering the compressor motor.
If something doesn't operate correctly in the dry run, you will have a loose cable, stuffed timer, stuffed item of switchgear, or stuffed transition resistors most likely. After that you're probably into the controller itself.

[trosten]

Very well explained...

[install monkey]

we got a model number yet,maybe a fault code?

[sachinp747]

hi i have mcquay chiller MNG105.2 HA ST model im facing problem for both Circuit A & B, Circuit A showing Alarm AL:E01 Exp A not recognized & Circuit B is Low Ambient tepm start up failure & with AL:206 Low Pressure Alarm #2 what the reason and how to remove this alarm