Results 1 to 9 of 9
  1. #1
    Join Date
    Sep 2019
    Location
    Utah
    Posts
    3
    Post Likes

    Adding a fan relay

    To whom it may reach..
    I added AC to a manufactured home (modular) furnace. The type where you slide the Mortex Coil in the bottom housing of furnace.(Downflow).

    My question is, and its probably a dumb one but here it goes.. I need to add a fan relay to kick the fan on when calling for cool. What type of fan relay will I need to install? Again probably a no brainer, but I just opened my doors back in April and Ive been so soo busy and too much on my mind to remember something so simple.. Thanks in advance and I hope this is the correct area to post this thread!

  2. #2
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    25,622
    Post Likes
    Quote Originally Posted by Stoutac View Post
    To whom it may reach..
    I added AC to a manufactured home (modular) furnace. The type where you slide the Mortex Coil in the bottom housing of furnace.(Downflow).

    My question is, and its probably a dumb one but here it goes.. I need to add a fan relay to kick the fan on when calling for cool. What type of fan relay will I need to install? Again probably a no brainer, but I just opened my doors back in April and Ive been so soo busy and too much on my mind to remember something so simple.. Thanks in advance and I hope this is the correct area to post this thread!
    Your profile says Owner / Tech so why an electric 101 question?

  3. #3
    Join Date
    Oct 2009
    Location
    Atlanta,Ga.
    Posts
    524
    Post Likes
    use something like a 90-340 relay, It is good for 6.9 amps.that is a generic relay number, made by several manufacturers.

  4. #4
    Join Date
    Jul 2019
    Location
    Oklahoma home its in the name
    Posts
    716
    Post Likes
    Does it not already have a fan relay for a g call? I would just let my thermostat call for g and make shure its the correct speed.

    Sent from my rotary telephone using Tapatalk

  5. #5
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    1,048
    Post Likes
    Rib u1c
    Use y to energize coil, pass line power through n.o. Contact

  6. #6
    Join Date
    Jul 2009
    Location
    Columbia, MD
    Posts
    5,855
    Post Likes
    Use G for the coil

    Take L1 from blower relay on board and land on C. Take NO on relay and wire to AC speed for blower.

    Take heat speed and put on NC on other contact on the relay. Make a jumper from heat speed tap on board and put on C on other relay.

    That way if someone has fan on and they turn the heat on, both heat speed and ac speed cant both be energized which will smoke the motor


    Sent from my iPhone using Tapatalk

  7. Likes heatingman liked this post
  8. #7
    Join Date
    Sep 2019
    Location
    Utah
    Posts
    3
    Post Likes
    Thread Starter
    Quote Originally Posted by pecmsg View Post
    Your profile says Owner / Tech so why an electric 101 question?
    Right! Soon as I got to looking at the wiring I knew exactly which relay to use and how to wire it..
    Single Pull Normally Open (SPNC)

  9. #8
    Join Date
    Sep 2019
    Location
    Utah
    Posts
    3
    Post Likes
    Thread Starter
    This puppy old. it's equipped with thermal disc type switches that turns on the only speed the motor has which was 1200 CFM.

  10. #9
    Join Date
    Jul 2009
    Location
    Columbia, MD
    Posts
    5,855
    Post Likes



    Sent from my iPhone using Tapatalk

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •