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  1. #1
    Join Date
    Sep 2004
    Posts
    522

    Failed muffler on O6D compressor?

    Can someone tell me how to determine if you have a bad muffler on a recip. compressor?

  2. #2
    Join Date
    Feb 2004
    Location
    Georgia
    Posts
    363
    Well, short of taking it off and examining it there would be no positive way.
    But if you had some problems like say cracked discharge lines or excessive gas pulsation type noise in the piping and maybe found some metal debris in the liquid line drier then you might have a bad muffler among other things.

  3. #3
    Join Date
    May 2001
    Location
    Western Wa
    Posts
    1,845

    Talking One way I knew...

    ..was when a piece of discharge valve vibrated its way through the can.

    That was about 6 months after I replaced the valves.
    God Bless our Veterans

    God Bless the USA

  4. #4
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,993
    Only failures Ive seen where cracks at the stubs into the shell of the muffler, or plugged up with debris and having a high pressure drop.
    Your poor planning does not constitute an emergency on my part!!!!

  5. #5
    Join Date
    Jun 2003
    Location
    in a tree looking in your window
    Posts
    1,166
    Couple of years ago one of my guys calls me and says he thinks he has a bad muffler on a Carrier chiller, compressor trips on high head after a few seconds, here is what I found.

    If you dont stand behind our troops, please feel free...........to stand in front of them.

  6. #6
    Join Date
    Oct 2003
    Location
    UTAH
    Posts
    145
    Quote Originally Posted by chillrdude View Post
    Couple of years ago one of my guys calls me and says he thinks he has a bad muffler on a Carrier chiller, compressor trips on high head after a few seconds, here is what I found.



    Nice...ever find the clip?

  7. #7
    I suspect I have just come across the exact problem the original poster might have been asking about. Carrier RTU. Two 6-cyl 06D's, one with two unloaders.

    I was in the process of fixing a control wiring problem when the compressor tripped over-current about 2 minutes after it loaded up for the first time in 4 years. (Thanks to another tech's lack of electrical knowledge, it had been running 4 years on only 2 cylinders since a control retro-fit.)

    Here are the numbers: Liquid line: 225 psig with 11 degrees sub cooling. Suction:74 psig, 19 degrees superheat. (high load) The discharge pressure was 415 psig! Disch superheat was 40-50 deg, so no significant non-condensibles. Not 100% sure, but I think the muffler is plugged? No pressure ports to test theory, but I did see a 20-degree temp drop across the muffler.

    This compressor was replaced 4 years ago by the same hack that butchered the control wiring. Although an 06D is fairly easy to change without the use of a torch, the lines were cut & re-brazed during the process by someone with no torch skill. I wouldn't think that 6% sil-phos beads from one 1-1/8" coupling could be enough to plug a muffler? Could it be full of valve/winding/burn-out material from previous failed compressor? I'd hate to recover all this R-22 & remove the muffler only to find it wasn't the problem. I may be in for some exploratory surgery on this thing tomorrow..... Any ideas? Will update when I find anything significant.

  8. #8
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Quote Originally Posted by sappman2 View Post
    I suspect I have just come across the exact problem the original poster might have been asking about. Carrier RTU. Two 6-cyl 06D's, one with two unloaders.

    I was in the process of fixing a control wiring problem when the compressor tripped over-current about 2 minutes after it loaded up for the first time in 4 years. (Thanks to another tech's lack of electrical knowledge, it had been running 4 years on only 2 cylinders since a control retro-fit.)

    Here are the numbers: Liquid line: 225 psig with 11 degrees sub cooling. Suction:74 psig, 19 degrees superheat. (high load) The discharge pressure was 415 psig! Disch superheat was 40-50 deg, so no significant non-condensibles. Not 100% sure, but I think the muffler is plugged? No pressure ports to test theory, but I did see a 20-degree temp drop across the muffler.

    This compressor was replaced 4 years ago by the same hack that butchered the control wiring. Although an 06D is fairly easy to change without the use of a torch, the lines were cut & re-brazed during the process by someone with no torch skill. I wouldn't think that 6% sil-phos beads from one 1-1/8" coupling could be enough to plug a muffler? Could it be full of valve/winding/burn-out material from previous failed compressor? I'd hate to recover all this R-22 & remove the muffler only to find it wasn't the problem. I may be in for some exploratory surgery on this thing tomorrow..... Any ideas? Will update when I find anything significant.
    They DO not plug or break. They're bullet proof.

    I suspect those unloaders are electric. How are they staged into the control circuit? Did you check amps to confirm full load ?

    You're wasting your time pulling that muffler.

    Plus you'll need 45% to get it back on.

    You said high load plus their coils are notorious for corosion to the point of poor heat transfer.
    Either that or they're dirty 2 pass coils and need to be cleaned thoroughly.

    I suspect the poster in the op is having mechanical issues with the compresser itself.


    MUFFLERS dont plug or break.

  9. #9
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Quote Originally Posted by chillrdude View Post
    Couple of years ago one of my guys calls me and says he thinks he has a bad muffler on a Carrier chiller, compressor trips on high head after a few seconds, here is what I found.



    Too bad it happened on the high side. Had to reclaim it didn't you.

    Ive had that happen but on the suction side 3 times but I see ALOT of 06 comps.

    Have 4 data centers filled with 30 ton Lieberts and 2 data center in Dallas. 23 Lieberts in each data centers with two comps each.

    Plus have some old Carrier 40 ton Condensing units with 06Es in them.

    I blame those foe my back problems.

  10. #10
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,787

  11. #11
    Quote Originally Posted by Six View Post
    They DO not plug or break. They're bullet proof.

    I suspect those unloaders are electric. How are they staged into the control circuit? Did you check amps to confirm full load ?

    You're wasting your time pulling that muffler.

    Plus you'll need 45% to get it back on.

    You said high load plus their coils are notorious for corosion to the point of poor heat transfer.
    Either that or they're dirty 2 pass coils and need to be cleaned thoroughly.

    I suspect the poster in the op is having mechanical issues with the compresser itself.


    MUFFLERS dont plug or break.
    The condenser coils aren't perfect, but they're good enough from the outside. I am considering the possibility of a restriction in the condenser coil itself, perhaps in the hot-gas header? I verified the condenser is not dirty. If it was my liquid line pressure would be high as well. There is definitely a restriction between hot gas line & liquid line. Only three devices exist in between: Discharge service valve, muffler, and condenser coil. Before I remove the muffler, I will unbolt the discharge valve & check it, however it back-seated just fine, shutting off the service port (no schraeder) so the valve disc is intact. If I verify the muffler is OK, the only thing left is the condenser.

  12. #12
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Your'e wasting your time.

    Does that unit have a big slab condenser coil ?

    If it does they're notorious for poor heat transfer when they start getting corroded.

    Put a water hose on it while its running. Does your head and liquid pressure close up ? Then no discharge restriction.

  13. #13
    Join Date
    Jul 2007
    Location
    The Hot South
    Posts
    1,336
    If he's got a 190# pressure drop between the hot gas Line and liquid line, then he's got a restriction somewhere. Putting water on the coil's not going to help.

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