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  1. #53
    Join Date
    Jun 2006
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    New Jersey
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    4,288
    Quote Originally Posted by thegoodlistener View Post
    You know I have never seen this happen on this kind of unit. Can you explain more on how this can happen? TIA
    It you push the contactor in......you now have current running through the compressor wire on the clo. So clo, now will send 24v to the contactor and keep it energized until it trips out on safety again.

  2. #54
    Join Date
    Jan 2008
    Location
    Dallas ,Texas
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    3,667
    Quote Originally Posted by ascj View Post
    It you push the contactor in......you now have current running through the compressor wire on the clo. So clo, now will send 24v to the contactor and keep it energized until it trips out on safety again.
    And this resets the lockout relay ? I just have never seen this before except on some older RTU's the a circuit board with the clo protection built into it. Just saying. I will try this when I get a chance.
    UA 100

    It takes three people to do anything around here. Two do the work, one explains to the crowd of people who showed up when they seen smoke and flames.

  3. #55
    Join Date
    Jun 2006
    Location
    New Jersey
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    4,288
    Quote Originally Posted by thegoodlistener View Post
    And this resets the lockout relay ? I just have never seen this before except on some older RTU's the a circuit board with the clo protection built into it. Just saying. I will try this when I get a chance.
    Another tech went to a no A/C on a 5 ton Carrier. Found bad condenser fan motor, replaced it. Two days later, no A/C. Another tech went out and diagnosed bad contactor. He measured 24v from the contactor to ground and when he pushed it in, it stay pulled in and ran.
    Next day, no A/C. I went there with the second tech. We find the unit locked out. I reset it. Checked charge, air flow, and amperages. I find the condenser fan drawing a little high amps. Kept checking the temp of the motor. It kept climbing. 25 minutes later the motor quits on thermal. Come to find out the original 1/3hp 825rpm motor was replaced with a 1/3hp 1075rpm. Installed right motor....all good.

    http://hvac-talk.com/vbb/showthread....ighlight=motor

  4. #56
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    16,998
    Quote Originally Posted by thegoodlistener View Post
    And this resets the lockout relay ? I just have never seen this before except on some older RTU's the a circuit board with the clo protection built into it. Just saying. I will try this when I get a chance.

    I remember the first time I saw one of these CLO thingies. I pushed the contactor in and the thing ran. I'm thinking, what the...

    So I called the service manager, and he told me I had just reset the lockout. I'm like, I did whaaat?
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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  5. #57
    Join Date
    Nov 2004
    Location
    Auburn, AL, USA
    Posts
    597
    Quote Originally Posted by ascj View Post
    Another tech went to a no A/C on a 5 ton Carrier. Found bad condenser fan motor, replaced it. Two days later, no A/C. Another tech went out and diagnosed bad contactor. He measured 24v from the contactor to ground and when he pushed it in, it stay pulled in and ran.
    Next day, no A/C. I went there with the second tech. We find the unit locked out. I reset it. Checked charge, air flow, and amperages. I find the condenser fan drawing a little high amps. Kept checking the temp of the motor. It kept climbing. 25 minutes later the motor quits on thermal. Come to find out the original 1/3hp 825rpm motor was replaced with a 1/3hp 1075rpm. Installed right motor....all good.

    http://hvac-talk.com/vbb/showthread....ighlight=motor

    ascj, looks like the CLO did a good job, just what it is there for.
    jt

  6. #58
    Join Date
    Nov 2006
    Location
    Southeastern Pa
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    16,998
    Quote Originally Posted by garytulsa View Post
    Can anyone help with this one? I have this 12 ton carrier package unit that has a call for cooling but compressors arent running or outdoor fans. I got voltage but contactors are not engaging. I was told to just hit the disconnect and give it five minutes and turn it back on and it will run. I took a look at it and and found the contactors wont pull in, with a little nudge they suck right in. any ideals what i can look for. model number 48 HJF 012 571HQ thank you for any help.

    Gaaaaary.....

    time for an update.........
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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  7. #59
    Join Date
    Jan 2010
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    5,812
    Quote Originally Posted by timebuilder View Post
    Gaaaaary.....

    time for an update.........
    He's still pushing the contactors in.

  8. #60
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    16,998
    I know, I'm just looking for a miracle....
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  9. #61
    Join Date
    Jan 2010
    Posts
    5,812
    Quote Originally Posted by timebuilder View Post
    I know, I'm just looking for a miracle....
    Or a Paul Harvey

  10. #62
    Join Date
    Apr 2010
    Posts
    21
    Time,
    Last time VTP99 posted and explained it real good and how the circuit connected to economizer to CLO. This morning i'm looking at the wiring diagram and we want to make sure there is no open circuit each one of those components parts. If we go back how the circuit connected and follow each components in a circuit you can find some may be open that's why C1 coil not pulling in. Here is the circuit connection that VTP99 laid out last posted, Y1 Blue to economizer plug in #2 connected #5 Gray to CLO1 terminal #2 to NC contact terminal #3 to HPS to LPS to C1 contactor coil make sure no open circuit there. And the common wire of C1 coil is Brown connected to FPT (Freeze up Protection Thermostat) which is Black wire connected to Brown common side of the 24VAC transformer. Let say the 24VAC RED make and passed to Y1 and you follow each connection should catch the open circuit as you go. And the FPT is common side make sure not open. I think we are good there, Thanks

  11. #63
    Join Date
    Apr 2010
    Posts
    21
    VTP99,
    Any luck on that Carrier unit yet!

  12. #64
    Join Date
    Jan 2010
    Posts
    5,812
    Quote Originally Posted by sdtech View Post
    VTP99,
    Any luck on that Carrier unit yet!
    Sd,
    Time put a shout out for Gary in Tulsa but so far no post yet. Sometimes you get that here. No end to the story It was Gary in post #1 that was pushing the contactors in.
    Time,
    Did you dig up a old board to bench test ?

  13. #65
    Join Date
    Nov 2000
    Location
    Hoggtown! Toronto, ON
    Posts
    1,133
    Quote Originally Posted by DavyB View Post
    Sounds like low line voltage to me. time for a new transformer?
    I remember once where the unit was rated for 208v or 240v. The transformer had spade connectors that could be set for either voltage. Same problem as the OP described was happening. Turned out it was the transformer. 208v was supplied but the transformer was wired for 240v. Not enough voltage to pull in the contactors.

    However this one is a 12 ton so its probably 208 or 575 3ph. I'd still be looking at the transformer...
    "...refresh my memory. When did I start caring about this stuff...?"

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