McQuay AGS 250

[largetonnage]

Model # AGS250B27-ER10
On start up circuit 2 runs about 40 seconds and alarms on low oil level. oil level in bottom glass of separator is full and at bottom of top glass during short run time. oil return solenoid is energized(120). EXV readings are good.
I'm thinking the problem may be the level sensor in the separator but don't know how to prove it. This is a new account with no service lits or IOMs. Any help would be appreciated.

Thanks

[subcoolguy]

I have a ags300b27-er10 that I am cutting my teeth on right now so I can't tell you a whole lot about it. try to look up the om agsbb4 and imm ags-1 manuals. I just looked in my operation manual om agsb4 and found that the default low oil level delay is 120 sec. I wonder if the delay is from call for start up. anyways what kind of sensor is on the oil level?..

[largetonnage]

the sensor is a Henry. I am assuming it is a level sensor.

[steveoo]

could be oil filter?

[freonrick]

oil filter will be oil differential, the oil level is a optical sensor on the bottom side of oil separator. also make sure the oil heater is working.

[subcoolguy]

Steveoo I think you ment to post in this thread friendYes there is a oil dp.check oil return line,strainer pressure drop .Some time if discharge s/h is to low it will cause foaming in oil and optic sensor will see low oil .adjust ball valve in front of oil return valve to keep dis s/h up and out of low dis s/h

[largetonnage]

oil heater is ok. I have some other things that need quoted for this job and wont get back till the approval. I will update then.

[largetonnage]

Update-was able to return-started pulling charge with the intent to change oil sensor-found circuit 270# low on charge. pressureized and found leak at suction coupling coming off evap. This is a victaulic coupling-ordered and changed gasket-515 on sealing surface and dry on clamp side. Still dont know why the lw oil level alarm showed first.

[steveoo]

it was 270 pound's low?That's a flooded evap,at 100% refrigerant should be visable in sight glass on evap.what is total charge 350-400?

[ryan1088]

Steveoo I think you ment to post in this thread friendYes there is a oil dp.check oil return line,strainer pressure drop .Some time if discharge s/h is to low it will cause foaming in oil and optic sensor will see low oil .adjust ball valve in front of oil return valve to keep dis s/h up and out of low dis s/h

That's what I was thinking too about foaming and the oil sensor reacting to that. The older ALS chillers we have are known to do that (I think it's the same sensor, just a lot better setup on the ags).

[freonrick]

make sure you check the oil return solenoid valve, I have found most leaks at that valve.

[largetonnage]

steveoo, total charge is 321#. leaks repaired, evacuated and charged, running good now.