J e hall unloader problem

[referdan]

Hello can anyone help with a problem with a V 92 6 cyl J E HALL ammonia compressor. I have low oil pressure about 15 psi and the unloaders will not load up. I changed the oil and cleaned the oil pump intake screen, did not help. I can manually operate the unloaders by forcing oil into port on bottem of unloader with hand oil pump but they will not load up on their own. Soleniods are working.

[GHAZ]

Hi Hall v92 compressor has 2 oil filters 1 inside the sump and 2nd at the back near the oil pump ,which cant be clean and has to be replaced because its like a cloth filter, and the unloading cage around the cyclinder has 2 miliflex seals which come in pairs 1 for liner and the other for the moving part of the cage,and if they are worn then the oil leaks out and the pins dont drop to lower the suction ring valve,

[Magoo]

Agree with GHAZ, you need oil pressure to load compressor, oil pressure is the real problem, from memory the minimum diff pressure above suction is 35psig. The loader sleave seals on piston liners can be a problem as they wear and go brittle with age.

[Grizzly]

Welcome to the forum referdan.
Just to ad to the good advice of Ghaz and Magoo.
Several things differ,dependant upon whether you have a Mk1 or Mk2 machine?
If i remember correctly the Mk1 is energise to unload and the Mk2 is energise to Load I think?
How many cylinders the comp has.
The oil strainer on a 3 or 4 cylinder machine is inserted heater rod style below the back end cover.
In the sump,as mentioned on a 6 or 8 cylinder machine.


Assuming you have not serviced the said machine recently? (Do you know when it was last serviced?)
The expected oil diff when running is between 30-50psi. The actual oil pressure shown by the gauges is not critical provided it is sufficient to close and maintain the oil diff switch in the closed position.

Proving with a hand pump each solenoid valve assembly seem to rule out the likelyhood of damaged or worn line seals.
Assuming you have proven each solenoid assembly.
Oil Temp?
The Oil Pressure Relief valve malfuntioning?
Has someone used a different oil to the norm?
Excessive internal wear.

It sounds as if this machine is due some TLC.
Good luck Grizzly.

[referdan]

Thank you gentlemen.I found the internal oil filter it was callapsed! very dirty.I have ordered some replacements.

[Josip]

Hi, referdan

Hello can anyone help with a problem with a V 92 6 cyl J E HALL ammonia compressor. I have low oil pressure about 15 psi and the unloaders will not load up. I changed the oil and cleaned the oil pump intake screen, did not help. I can manually operate the unloaders by forcing oil into port on bottem of unloader with hand oil pump but they will not load up on their own. Soleniods are working.

Thank you gentlemen.I found the internal oil filter it was callapsed! very dirty.I have ordered some replacements.

I don't want to be rude, but we have to check complete oil circuit when we have low oil pressure ....

.... oil filters the first, because they are installed to protect machines from some other bigger damage ...

Best regards, Josip

[Grizzly]

Thanks for the post referdan.
I am gad you were able to sort your problem.
May I add for us oldies it's sometimes a case of "The more you know the worse the problem is".
Sometimes forgetting, or assuming the obvious.
If you need any more assistance just post. There are a lot of "us" with Halls knowledge.
And welcome to the forum.
Grizzly

[Josip]

Hi, Grizzly

Thanks for the post referdan.
I am gad you were able to sort your problem.
May I add for us oldies it's sometimes a case of "The more you know the worse the problem is".
Sometimes forgetting, or assuming the obvious.
If you need any more assistance just post. There are a lot of "us" with Halls knowledge.
And welcome to the forum.
Grizzly

Agree with you, this is not the first time when we try to help, but .... due to missing "root" info from OP we are heading our detection in wrong direction .... that's the reason to ask OP for as much as possible information ...


Best regards, Josip

[HallsEngineer]

Check your loading seals also as they cause these symptoms.

[Grizzly]

Check your loading seals also as they cause these symptoms.

You didn't bother to read the above posts then?
Grizzly

[HallsEngineer]

Yes i did.