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Thread: Partially plugged Condenser! R134a cap tube system

  1. #1
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    Partially plugged Condenser! R134a cap tube system

    New on on me. Have a Victory reach in cooler. Cap tube and R134a.

    Condenser is about 120F at the top and about 1/3 of the way down the condenser, the temperature drops to below ambient.

    Have never run into this before. Coil is clean, no apparent external damage. Not sure WHAT is in there! Any clues from the crew?

  2. #2
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    I have never seen a condenser coil plugged internally!

  3. #3
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    Thread Starter
    Had one plugged from the factory, but this is the first example in one that has been running. Will pull the coil and see what comes out....

  4. #4
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    Quote Originally Posted by Juan Madera View Post
    New on on me. Have a Victory reach in cooler. Cap tube and R134a.

    Condenser is about 120F at the top and about 1/3 of the way down the condenser, the temperature drops to below ambient.

    Have never run into this before. Coil is clean, no apparent external damage. Not sure WHAT is in there! Any clues from the crew?
    I can think of several things it could be Juan, but they would all be off the cuff guess without the whole story. What was the initial complaint call? Was it running when you arrived? What was/is the refrigerant gas pressures? Was/is the pot hot? Was the suction line cool to the touch? Is this unit a known leaker?Ok, now for my WAG's... low on gas, bad or leaky comp. valve? Notice i did not guess an internal cond. blockage and or restriction? The reason being, that almost NEVER happens in the real world, but is just water cooler war story talk. In all my years i have only seen one internal restriction which was the head of a pencil planted in a McQuay cond. unit by a disgruntled union worker. LOL... PS: Give us more to go on Juan...

    PS: I see I'm late to the party again, as you had 3 responces while i was typing..

  5. #5
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    The only time I had an internal restriction in a condenser was on a 5-ton A/C condensing unit which just had a compressor replaced due to bad valves. I determined it was in the condenser after installing a pressure tap on the discharge line and on the condenser outlet ahead of the filter-drier. As it turned out, the blockage cleared itself after several restarts.

    I then found the offending valve pieces in the filter drier. They must have all got stuck in a return bend and simply broke free.

    In this case, I think Juan should verify the blockage by checking the condenser pressure drop. To get flashing internally I would expect 10 psi drop or more. Less than 5 psi I think would be about normal.

  6. #6
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    Plugged cap tube/drier. Gas stacking in the condenser.

  7. #7
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    Still waiting for my first plug condenser.

  8. #8
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    Quote Originally Posted by VTP99 View Post
    Still waiting for my first plug condenser.
    Attached Images Attached Images  

  9. #9
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    Had a condenser coil one time with white powder in it. Blew it out looked like chalk dust.

  10. #10
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    Iz, This is only the first one that has been running (under my care for 6 years now) Did have one "factory fresh" that when fired up in heating mode iced 3/4 of the outdoor coil. Someone at factory brazed the inlet to that pass shut.

    Anyway, first thought was cap tube plug. (my absolute favorite thing.) But, the condenser discharge was cold! Took the guards off the sides of condenser to inspect hairpin bends. Rany my "calibrated" hands over the hairpins and the top 1/3 were almost hot enough to be uncomfortable and the bottom 2/3 were actually chilly, hence my suspicion of a blockage.

    This unit has had a blocked cap, so it has a new F/D, amputated caps tubes and a new charge probably 6-8 months ago.

    Being as I swapped in a spare, I have been waiting for an opportune time to dig into this.

  11. #11
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    Quote Originally Posted by Juan Madera View Post
    Iz, This is only the first one that has been running (under my care for 6 years now) Did have one "factory fresh" that when fired up in heating mode iced 3/4 of the outdoor coil. Someone at factory brazed the inlet to that pass shut.

    Anyway, first thought was cap tube plug. (my absolute favorite thing.) But, the condenser discharge was cold! Took the guards off the sides of condenser to inspect hairpin bends. Rany my "calibrated" hands over the hairpins and the top 1/3 were almost hot enough to be uncomfortable and the bottom 2/3 were actually chilly, hence my suspicion of a blockage.

    This unit has had a blocked cap, so it has a new F/D, amputated caps tubes and a new charge probably 6-8 months ago.

    Being as I swapped in a spare, I have been waiting for an opportune time to dig into this.
    Copy that Juan, and thanks for the reply. I have no doubt you will find the blockage if there is one, so all the best to you. If you do pull it, and dissect it, please let us know what you find. Take Care!

  12. #12
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    So; We swapped in a good reach in in for the troubled unit. Let it sit for a couple of days, plugged back in to show one of my techs and the stoopid thing works like a champ! Only explanation I can think of is that whatever was blocking the pass in the condenser was shaken loose by the moving experience and now is floating free in the system. High hopes that this "sleeping dog" will end up in the F/D and not reoccur. Crazy stuff...

  13. #13
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    Yeah, well if it was easy stuff everyone would be doing it.

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