york yt centrfugal

[cannedheat]

learning to maintain chillers and also taking a class at the the 597 training school. my question is I had an oil analysis come back suggesting an oil change on yt chiller, oil was dark and analysis showed slight traces of acid. their suggestion was to change oil. not having done this before, our shop has a hyperwatt machine to raise pressure. from my understanding im supposed to connect water hoses to drain and vent ports on evap head one on each end of evap barrel, after hyperwatt is powered up, calibrate to atomphere pressure and connect 1/4 refrig line to any port coming off of evap barrel.set hyperwatt to say 5 psig and start hyperwatt machine pump and heater. run until pressures become positive on evap barrel. at this point can I now drain oil from sump into a bucket until it stops draining? then proceed to manualy pump in new c oil, in the amount I drained? then close off drain valve and power off hyperwatt machine. this is my understanding of what needs to happen. any further feedback whould be helpful. thankyou cannedheat

[RichardL]

I would humbly suggest a few additional items to your work list.

1- Valve off chill water @ chiller, observe the pressure increase on the CW since it is now contained and will rise greatly.
2- Remove CW sensors from thier wells as they seem to go to Wally-World under the high temps subjected to.
3- Remove the large 20 amp fuse in the control panel before removing the oil, or prepare to relace the oil heater.
4- Make DAMN sure your "Hyper-Watt" heater is fully grounded before energizing the heater.
5- Leave the oil heater energized until the very last to prevent refrigerant migration into the cold oil.
6- Before removing the oil and screwing up any hope of using your H-10, perform a leak test on the entire compressor & related lines.

Try and not get dead.....That feat is Non-Habit forming.

[cannedheat]

Richard l , thank you for the response. sounds like your saying to deenergize the heater before removing the oil.and then after adding new oil energize the heater to bring oil temps back to operating temps before turning off hyperwatt to avoid refrigerant migration. sorry I didn't add your other suggestions in my original post,valves will be off .had know idea about removing sensors, hyperwatt will be grounded. and leak check will be performed when evap pressures are in a positive.before removing old oil. thanks for the tips .

[Tech Rob]

Best way to go is with a small gear pump. Pump the old oil out while the machine is still in a vacuum, and suck the new oil in with the vacuum. If you do decide to waste 4 hours and do it with the water heater, I would say that 5# is way too high. You don't need any more than 0.5# to get the oil out.