Results 1 to 8 of 8
  1. #1
    Join Date
    Mar 2004
    Location
    midwest
    Posts
    954
    Have a Rps20BA rooftop not getting power to pump down solenoids for some reason? Wiring diagram is missing, we got a copy of a orginal OM manual but can't read the print. Unit looks modified control wise with relays and wires. I understand that Mcquay might had a tech bulletin on these units to bypass the pump down solenoids due to problems?
    An astronaut stuck in space was asked by a reporter, "How do you feel?"
    "How would you feel," the astronaut replied, "if you were stuck here, on top of 20,000 parts each one supplied by the lowest bidder?"

    "do it right or do it twice"

  2. #2
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    Try this site

    http://mcquay.hvacrcat.com/mcquay.as...zlMcPdcpklikhj,112437&w=r

    Type in RPS and look for the IM (instalation manual) for the RPS Vintage B. You can download a manual there. I will look for a service bulletin on the subject.

  3. #3
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    That link isn't doing what I wanted it to do. I will try again shortly.

  4. #4
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    I'm not sure downloading the manual from McQuay is worth the effort. It is a poor scan that you can barely read. Anyone else have any suggestions?

  5. #5
    Join Date
    Jan 2005
    Posts
    175
    Got to love those "modified" units. Sounds like to me that it is an older machine. Ain't nothin' to rewire correctly, I have done it numerous times with excellent results and running better than the way it was running before I got there.

    When you say "no power" to the solenoids, do you mean it stays in a pump down mode or will not de-energize to pump down?

    Either way it could be a bad wiring problem or a relay that is not working correctly. Trace wires back from solenoids and see which relay(s) are controlling it and then find the control that controls the relay.

    It is possible that the coil itself is bad, getting power and not energizing.

  6. #6
    Join Date
    Mar 2004
    Location
    midwest
    Posts
    954
    No power to solenoids at all. We will have to trace wires and tag them/label.
    An astronaut stuck in space was asked by a reporter, "How do you feel?"
    "How would you feel," the astronaut replied, "if you were stuck here, on top of 20,000 parts each one supplied by the lowest bidder?"

    "do it right or do it twice"

  7. #7
    Join Date
    Aug 2003
    Posts
    42
    You might want to check on the output board, next to the relay for the LLSV the mini 5 amp fuse,it looks like a resistor and pulls out with a pair of tweezers/pliers.

  8. #8
    Join Date
    Aug 2003
    Location
    Baltimore area
    Posts
    1,818
    Originally posted by johnnyc
    You might want to check on the output board, next to the relay for the LLSV the mini 5 amp fuse,it looks like a resistor and pulls out with a pair of tweezers/pliers.
    BINGO ! There have been problems with some of the older solid state relays on the board (black ones with screw in the middle). Do not rely on the red light to tell you it is powered.

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