Page 3 of 3 FirstFirst 123
Results 27 to 36 of 36
  1. #27
    Join Date
    Jul 2012
    Location
    Southwest
    Posts
    114
    If his oil filter is fouled he will see lower oil pressure. I keep seeing about a 10-15 psi difference between the discharge pressure and the oil pressure. So, when I see 30+ I start thinking change the oil filter. He never listed the oil pressure. After reading all the responses it looks like he could be overfeeding liquid because of transducers not reading accurately?

  2. #28
    Join Date
    Jul 2007
    Location
    The Hot South
    Posts
    1,317
    Quote Originally Posted by B1978 View Post
    If his oil filter is fouled he will see lower oil pressure. I keep seeing about a 10-15 psi difference between the discharge pressure and the oil pressure. So, when I see 30+ I start thinking change the oil filter. He never listed the oil pressure. After reading all the responses it looks like he could be overfeeding liquid because of transducers not reading accurately?
    This chiller doesn't use transducers, it uses temp sensors. He never listed oil pressure and probably didn't check oil pressure. I agree that more than likely he is overfeeding refrigerant. That's why I said if he determines he isn't overfeeding, it could be a restricted oil filter.

  3. #29
    Join Date
    Mar 2011
    Location
    North Carolina Piedmont Area
    Posts
    449
    Quote Originally Posted by R123 View Post
    This chiller doesn't use transducers, it uses temp sensors. He never listed oil pressure and probably didn't check oil pressure. I agree that more than likely he is overfeeding refrigerant. That's why I said if he determines he isn't overfeeding, it could be a restricted oil filter.
    R123 and B1978 have a good point that the oil pressure needs to be checked. Especially after the system has had a new compressor installed, its possibly that metal fragments are floating around in the system and may have caused a restriction in the oil filter. If its pressure drop is greater than 25 PSI (maybe even 20) it should be replaced because it showing signs that its plugging up. But I would be interested in what you guys are recommending it be replaced at?

  4. #30
    Join Date
    Jul 2012
    Location
    Southwest
    Posts
    114
    Im not a very experienced Chiller Tech, but I like your 25psi number. So say your Discharge pressure is 200, your oil pressure should not be lower than 175. Its pretty painless to change an oil filter, its a 2 hour job even for a rookie like myself. Some sites keep a few extra, with the gaskets on site.

  5. #31
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,388
    Quote Originally Posted by alcomech View Post
    ...If its pressure drop is greater than 25 PSI (maybe even 20) it should be replaced because it showing signs that its plugging up. But I would be interested in what you guys are recommending it be replaced at?
    i prefer to use the table in the manual...

    as for the pressure drop measurements, there is a tap on the front of the compressor oil filter (that's the 'in') and the tap on the top of the compressor, pointing up, by the solenoids is the 'out' of the compressor oil filter...remember to use 1 gage!
    Attached Files Attached Files
    When I am late for work, I usually make up for it by leaving early.

  6. #32
    Join Date
    Sep 2005
    Location
    Maryland
    Posts
    221
    Thanks for all the great info guys. I did check the top port for the oil filter outlet and it was 215. My head I believe was around 245, so I am running about a 30 psi drop across the filter. I have the filter and gaskets on order, I'll verify operation after that's changed to see if over feeding is an issue. I'll also double check the discharge superheat before/after I change out the filter. Thanks again guys.

  7. #33
    Join Date
    Mar 2011
    Location
    North Carolina Piedmont Area
    Posts
    449
    Hey Jay, thanks for the info. You are absolutely right to check that table which corresponds to the 90 ton unit. I didn't realize that there is such a big difference. I have a RTAA 200 which presents an oil alarm if over 27 PSI.

    You are the Master!

  8. #34
    Join Date
    Jul 2007
    Location
    The Hot South
    Posts
    1,317
    Quote Originally Posted by alcomech View Post
    Hey Jay, thanks for the info. You are absolutely right to check that table which corresponds to the 90 ton unit. I didn't realize that there is such a big difference. I have a RTAA 200 which presents an oil alarm if over 27 PSI.

    You are the Master!
    Actually, you need to be looking at the table that corresponds to the compressor, not the unit. In the case of the 90 ton chiller, it has one 50 ton compressor, and one 40 ton compressor so you need to look at both tables.

    Your RTAA 200 is completly different than the smaller 70 to 125 ton RTAA chillers. The larger chillers use a pressure differential switch and it should be set to trip at 50 3.

  9. #35
    I had this problem a few months ago.
    It ended up being a bad oil solenoid valve.
    The one right above the compressor on the oil line between the compressor and oil filter.

    Good luck.

  10. #36
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,388
    Quote Originally Posted by Iamclayman2000 View Post
    I had this problem a few months ago.
    It ended up being a bad oil solenoid valve.
    The one right above the compressor on the oil line between the compressor and oil filter.

    Good luck.
    OP has a different compressor/system than yours.
    When I am late for work, I usually make up for it by leaving early.

Page 3 of 3 FirstFirst 123

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event