York Screw Oil Problem

Company recently took over an account, has York Screw YS series R-22.Unit is 5 yrs old, maintenance supervisor told me problem started 3 yrs ago.
Problem:
Unit would not start due to "low oil in separator"
(holds 10 Galllons York "C") added 5 gallons to start unit.
Evaporator site glass foaming and color yellow, looks like completely full of oil.Checked check valve in discharge it holds.
Oil cooler is plate exchanger, liquid refrigerant from bottom of conderser 1/2 line feeds to top of cooler. 3/8 line out to bottom of evaporator.
Oil temp entering 145f,
3/8 line out is 130f,
HP 225
SP 71
No one at the site knows what other company did to this machine,said they would get it started. Every two weeks return to re-start.
I suggested to completley open up system, drain evap of all oil,check to see if oil cooler is defective.change all strainers and filters.
With no records of what was done I told my boss want to start from the beginning and check everything on machine.
Just want to hear if anyone has had a similiar problem.

hi tomt,

I do not have much of experience with these compressors to start with.

If the humidity indicator shows yellow, then its a bad sign of humidity in the system.
You did not mention if this is a water chiller condensing unit or any other system.

You can not know the amount of water in the system.
In such a case, I would recover all the refrigerant, then all the oil and check for acidity, preform pressure check with OFN , especially if its a water chiller.

vacuum for at lest 48 hours, brake the vacuum, fill fresh, clean oil, charge through the high side with 80% of refrigerant, start up, let it balance, add the remainning refrigerant and check all the components for propre work.

Do not forget to make a log of all your activity.

Let us know how did it go.

Chemi :)

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Unit would not start due to "low oil in separator"

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In you saying this does this mean the controller was telling you this.?
If so what if it relied on this input to open the oil seporator and let oil go into the reservoir?

Did you mean when you said the sightglass was yellow ,that it was yellow because of what was flowing through it i.e. oil?

Hi tomt,

Sounds like the eductor filters need to be changed, also a minimum slide valve position of 30% is needed to stop the oil falling back to the evaporator at low loads. What are the superheat and subcool on full load, also the ewt,lwt and condenser temps etc....if oil has been added with no evidence of an oil leak then it will have to be drained off again, i've had to short the oil level switch on some machines to allow oil to recover under full load.

Alec

Well talked them in to opening up the unit. Recovered r-22 578 lbs (total charge 925). Drained 9 gallons of oil out of evaporator, 7 gallons out of oil separator, units oil charge is 10 gallons. Removed oil filters and strainers and replaced.
Filters on the eductors have teflon seals, someone used pipe dope to try and seal them. WHAT A MESS.
Removed all the oil lines and cleaned.
Pressure checked and evacuted.
Had only 200 lbs of r-22 on site have to go back next week to finish topping off.
The Factory Reps where the contractor on this unit for the last 5 years.
What the heck are they teaching in these schools today.
CLEAN AND DRY first thing I learned when I started.
Was told that constantly.

Check R22 Charge. These machines are sensitive to low charge. If undercharged the oil return lines are above the liquid level. The upper oil return line is only efective at low load conditions. If it is an older unit you can try energising the solenoid valve whenever the compressor is running. Check minimum load allowance (requires second level password). High condenser water temperature can also cause oil loss very quickly.

Hi,
It means the carryover of oil is high that the discharge check valve is not closing after it shutdown it reversed the rotation that provide the apath to open the suction where the oil migrate to evaporator. Open up the discharge of the compressor it has a spring replace it. Also remove and replace the oil when it is restart-up

Watch the nameplate charge, it may be incorrect. I have weighed in the charge and the machine will carry over and wash the oil out of the seperater and you'l get an overcharge alarm. I'm from Philly too, the local Jork office seems to be in disaray anymore. Oh well, more work for us. :)

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Originally Posted by tomt

Well talked them in to opening up the unit. Recovered r-22 578 lbs (total charge 925). Drained 9 gallons of oil out of evaporator, 7 gallons out of oil separator, units oil charge is 10 gallons. Removed oil filters and strainers and replaced.
Filters on the eductors have teflon seals, someone used pipe dope to try and seal them. WHAT A MESS.
Removed all the oil lines and cleaned.
Pressure checked and evacuted.
Had only 200 lbs of r-22 on site have to go back next week to finish topping off.
The Factory Reps where the contractor on this unit for the last 5 years.
What the heck are they teaching in these schools today.
CLEAN AND DRY first thing I learned when I started.
Was told that constantly.

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your system is over charged with oil,so drain oil untill top sight glass 1/4 sight glass and ur system with pulldwn contro around 30min with ur 55amp of ur full load let u check wether ur oilstart coming on ur top sightglass ,chek ur oil return lines are working perfectly and run ur system low load slidevalve to recover oil fro evoprator other wise ur system must flush with N2 pressure

Clean the eductores change filters deshidratadores and oil strainer, verfique flowrate correct the evaporator, verify that the ball valves of the eductores and filters are open

Can the pickup get clogged even if youve changed oil consistently throughout the life of the truck at 3K with good oil and filter? Im at 107K on my 03 and have not have this problem yet.