Effects of capillary tube plugged - Page 5
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  1. #53
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    Jun 2013
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    French head pressure increasing

    Quote Originally Posted by Brian8383 View Post
    Does anyone have any idea what this guy just said?
    COOLP and Bry:

    U Funny guys! , yes?

    Hah!

    Just in my experience in pumping down (not sell U ) gt chillers, w:w hp and water to air single-cycle
    without rev valves...
    ( where was ya in 1980-1993?)
    Dealers and watching them and doing such... head pressures can go HIGHER a bit...

    What U not understand of my french?
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

  2. #54
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    Feb 2011
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    Peoria, IL
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    LOL!

  3. #55
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    Aug 2012
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    Maine
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    180
    Well it's the relationship between heat absorbed in the evap, refrigerant flow rate and time the refrigerant spends in the condenser. On a properly charged system with a restricted cap tube less heat is picked up in the evap, less refer flow is going into the condenser. The refer spends more time in the condenser and is able to give up more of it's sensible heat. Thus your subcooling is higher and your high side pressure will be lower. It has to, remember temperature and pressure are linked together. Want to prove the theory then hit the condenser with water, this accomplishes the same thing, removing more sensible heat from the refer. Now if some yahoo overcharges it to compensate for low suction to the point of severly reducing the area where condensation can occur then the head pressure can go up. With a now normal suction pressure and superheat you are forcing the refrigerant to travel faster and the evap to operate as normal, but now the condenser will be backed up with liquid, essentially acting as a smaller condenser. So now you have an evap that is absorbing heat as it's designed rate, but a condenser that is not rejecting enough of that heat, thus the head increases.

  4. #56
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    what JD say,, y'all.
    ... however, much work still needs to be done.
    CLOSED LOOP newer ratings are listed, but in numerical EER's Closed- is posted below OPEN LOOP EER's:

    http://www.energystar.gov/productfin...r=0&lastpage=1

  5. #57
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    Jul 2011
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    Nanaimo,BC, Canada!
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    Well said!

  6. #58
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    Jul 2009
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    new york
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    Quote Originally Posted by Frostmonkey74 View Post
    Well said!
    So we all in agreement that both side pressure will be lower than normal. Well said

  7. #59
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    Quote Originally Posted by bwd111 View Post
    So we all in agreement that both side pressure will be lower than normal. Well said
    In a perfect world, I agree.

    I rarely see a unit in "perfect world" status.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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  8. #60
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    Aug 2012
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    Maine
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    Yes in a perfect world everything works according to theory. Now the scenario I used assumed everything else was operating normally. Add in a bunch of noncondensibles from an improper install and now that restriction will raise head pressure. Sometimes when we are troubleshooting we have more than one problem causing the symptom. Lets say we come across a unit with a restricted cap tube and high head pressure. We recover the refer and fix the restriction. (Yes I know you could pump the refer into the condenser and do the repair but in this instance we chose to recover.) Vacuum to 500 microns and maybe this time we use virgin refer to charge. Voila we now have proper suction and head pressure. We just fixed both issues assuming it was only one. If you didn't know that there was noncondensables in there you would swear that a cap tube restriction causes high head. So yes Timebuilder is correct in that in a perfect world every unit you come across would have only one problem. How many times have you looked at a condenser coil and would swear that it looks clean only to discover that it's a split coil with a carpet of dirt between the coils. As these units age they often develop multiple problems due to age, neglect, or bad service practices.

  9. #61
    Join Date
    Sep 2002
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    12,127

    In summation:

    So, as I understand it now, five pages later, if a cap tube is restricted the head pressure will be higher. Or lower. And the suction pressure will be lower? Is that about it?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  10. #62
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    Jul 2011
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    Nanaimo,BC, Canada!
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    Quote Originally Posted by Poodle Head Mikey View Post
    So, as I understand it now, five pages later, if a cap tube is restricted the head pressure will be higher. Or lower. And the suction pressure will be lower? Is that about it?
    Bahahaha pretty much!

  11. #63
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    Aug 2012
    Location
    Maine
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    If the only problem is a restricted cap tube with a proper system charge then the suction will be low and head pressure will be lower than normal.

  12. #64
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    Nanaimo,BC, Canada!
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    This thread keeps going in circles!!

  13. #65
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    Jul 2013
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    63
    Quote Originally Posted by Frostmonkey74 View Post
    This thread keeps going in circles!!
    It does. Everyone wants to condemn someone for saying you'll get a high head low suction when we've all seen it (unless all we work on is package units). Type in low suction high head and see what you get on this forum. Restrictions. Very rarely do you get a perfect system like a package unit from the factory. That is when you get the lower than normal suction and head. But instead we get the 75 foot line sets, old as hell, not evacuated properly and so on and so forth. With that said, it is possible to get both. I won't lie. I've gone and hooked up my gages and said "oh it's low" and out charge in of only to see my head rise. Then say opps restriction. When it's hot hot hot and you're ****tin and gettin it happens. Hopefully you realize dumping charge in isn't the solution.

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