Never Mind What Oil, How much is the Question?

[get the gauges]

I took three times the correct oil charge out of a newly fitted L'unite 5hp comp once,
Jon

I did the same once(in my earlier days) when i came to a 7.5hp prestcold that had no oil in it so i put a load in it just to make the oil pressure switch.20 mins later i had the customer on the phone saying the compessor was moaning like the millenium falcon, you live and learn.

[Lowrider]

When changing the oil weigh or measure the amount of oil you take out and only put the same amount in plus up to a max of 10%. Run the system at least one hour in full load and check oil level according to the manual (running or standing still).

Never ever put the standard amount in after an oil change! You'll overfill it for sure!

[Grizzly]

Run the system at least one hour in full load and check oil level according to the manual (running or standing still).

It's also important to spend time with the equipment when adding oil as it can appear to be correctly charged one minute then can be over filled as oil is returned to the compressor under certain operating conditions.

And never add oil to a system where you are not 110% sure that it has a full charge of refrigerant.

I lost count of how often I seen compressors overcharged with oil after refrigerant leaks have been repaired and the system re-gassed.

All the above are relevant because to explain.
When a compressor/ system runs for a long time unloaded. Oil is "carried over" into the system but!
Because the swept gas volumes are low the oil is not returned to the compressor.
Basically ( AS ALREADY STATED) never assume a system is short of Oil, especially if it runs unloaded for long lengths of time and Always fully load a system before any maintenance checks / diagnosis is carried out.
Sight Glasses, Oil or Refrigerant are useless until full load conditions are achieved especially true on Chiller Systems.
Hopefully someone has benefited from this info?
Cheers Grizzly