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  1. #1
    Join Date
    Mar 2008
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    6

    Goodman 2.5 50 foot run, pulsing on discharge line

    Hi all new to the forum.

    I belive I have posted this else where and no response. I installed a Goodman 2.5 ton unit, with the furnace 50 feet from the condenser. Installation went well, charged to factory specs, called goodman to verify the amount of r22 to go into a 50 ft line set. The lines are 3/4, 3/8. Started the unit after a good deep vacume, let it pull for an hour. Charged with the amount, started the unit and it cools fine. Now the pulsing problem. The suction line, right at the evap coil "pulses" It sort of jumps. It started pretty steady, no knowing what to do and the customer asking is that normal, i added a bit more 22. The pulsing slowed. Using my superheat/cool guage(a fieldpiece, not a plug for them just what I use to do my superheats/cools) all was okay there. So I added a bit more r22 and the pulsing slows even more, now just a random bump every couple mins or so. Could it be I have a ball of silfoss in where the dischage goes into the evap coil? I have never done such a long run of copper before, furnace was on the driveway side, so could not put condenser on that side of house. Any thoughts on what I should do next? This was last june I installed, it worked fine, hense the pulsing till september. Live in northern Canada, so residential units only run at max 5 months out of the year. I have the info on how much r22 I put in at the customers house, my record keeping seems to stay much better that way. Is there something I am over looking or is this a bigger problem?
    Thanks
    Tim

  2. #2
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,513
    pressures high and low
    what are the gauges doing at the time of pulse
    superheat
    subcool
    out side temp
    inside temp
    td accross the coil
    air flow cfm calculated
    static pressure supply return
    amp draw of compressor and blower
    voltage reading of unit


    with out any of this cant say for sure

    sounds like noncondensable to me but only a guess

  3. #3
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,350
    Is this "pulsing" you're speaking of on the liquid line feeding the metering device? Is it a piston/flow rater metering device or a TXV? What were your pressures, saturated temps, superheat and subcooling running at when you noticed these pulses?

    Off the cuff, "pulsing" in the liquid line can mean flash gas...the liquid in the liquid line is experiencing pockets of the liquid flashing off into vapor due to either being heated (such as a liquid line in a hot attic) or a long length of undersized liquid line, creating a pressure drop.

  4. #4
    Join Date
    Aug 2005
    Posts
    215
    The questions the other 2 posters asked are very important... If you could provide that info, you will find your answer to the problem your having...

    Did you ask goodman if that 50ft run of copper was properly size with 3/4 -3/8 copper?

  5. #5
    Join Date
    Mar 2008
    Posts
    6
    Quote Originally Posted by tinknocker service tech View Post
    pressures high and low
    what are the gauges doing at the time of pulse
    superheat
    subcool
    out side temp
    inside temp
    td accross the coil
    air flow cfm calculated
    static pressure supply return
    amp draw of compressor and blower
    voltage reading of unit


    with out any of this cant say for sure

    sounds like noncondensable to me but only a guess


    This is all going to be rechecked come spring/summer, just looking for anyone who has run into this or has an idea off the top of the head.
    Thanks, and will post the results of these tests when I get to the unit, weather permiting.

    Tim

  6. #6
    Join Date
    Mar 2008
    Posts
    6
    Quote Originally Posted by marlboroman View Post
    The questions the other 2 posters asked are very important... If you could provide that info, you will find your answer to the problem your having...

    Did you ask goodman if that 50ft run of copper was properly size with 3/4 -3/8 copper?
    Yes, I let them know that. They said it was fine.
    Tim

  7. #7
    Join Date
    Dec 2007
    Location
    Ohio
    Posts
    2,876
    Doesn't all of this qualify as DIY???
    I need a new signature.....

  8. #8
    Join Date
    Mar 2008
    Posts
    6
    Quote Originally Posted by shophound View Post
    Is this "pulsing" you're speaking of on the liquid line feeding the metering device? Is it a piston/flow rater metering device or a TXV? What were your pressures, saturated temps, superheat and subcooling running at when you noticed these pulses?

    Off the cuff, "pulsing" in the liquid line can mean flash gas...the liquid in the liquid line is experiencing pockets of the liquid flashing off into vapor due to either being heated (such as a liquid line in a hot attic) or a long length of undersized liquid line, creating a pressure drop.
    Its a cap tube metering device, no TXV. Stated in the other replys, will get this info again when I can get back to customers house. I have though myself the pressure drop, but using rated size tubing, according to goodman it should be okay. The line is in the basement, thats going to be my first trial, insulating the discharge line part way, mabye it is flashing along the way.

    Tim

  9. #9
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,950
    Sorry mooka, but your use of HVAC terminology doesn't sound like you're a pro to me. If you have a fixed metering device (no, you do not have a cap tube metered unit because Goodman never used cap tubes for metering.) then the only thing I can think of that would create pulsing is contaminates in the system.

    Leaving a vacuum pump on for an hour is a useless measure of whether it evacuated the system. In fact, it could just as well have pulled moisture into the system if there was a leak somewhere during evacuation.

    Despite all of the attempts to sound like a pro, there is not one useful bit of information in any of your posts.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  10. #10
    Join Date
    Mar 2008
    Posts
    6
    Quote Originally Posted by RoBoTeq View Post
    Sorry mooka, but your use of HVAC terminology doesn't sound like you're a pro to me. If you have a fixed metering device (no, you do not have a cap tube metered unit because Goodman never used cap tubes for metering.) then the only thing I can think of that would create pulsing is contaminates in the system.

    Leaving a vacuum pump on for an hour is a useless measure of whether it evacuated the system. In fact, it could just as well have pulled moisture into the system if there was a leak somewhere during evacuation.

    Despite all of the attempts to sound like a pro, there is not one useful bit of information in any of your posts.
    I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
    Tim

  11. #11
    Join Date
    Mar 2005
    Location
    Suppy NC
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    4,513
    Quote Originally Posted by mooka View Post
    I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
    Tim


    you pulled it down to 100 microns in an hour
    then you filled it with nitro> I hope you pulled it back down before you let the refrigerant into the system. If not then there is a very good chance you will need to let the smoke out before you replace he compressor

  12. #12
    Join Date
    Aug 2002
    Location
    Southold.calm
    Posts
    5,750
    Quote Originally Posted by mooka View Post
    I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
    Tim
    Its tough to fool a RoBoTeq!

  13. #13
    Join Date
    Apr 2004
    Posts
    7,680
    Me thinks a hold of 100 microns for an hour is nearly impossible. (Your hoses leak more than that).

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