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Thread: traulsen

  1. #14
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    Quote Originally Posted by KB Cool View Post
    Why would the refrigerant migrate to the compressor in the off cycle? Unless compressor location is below box temp? Correct?
    It can be with the defrost heaters

  2. #15
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    Quote Originally Posted by dangpgt97 View Post
    It can be with the defrost heaters
    Yes, your right! I never thought of that. The heaters come on and the refrigerant then starts migrating to the compressor. Cool!
    Another question? On a pump down system why is there still CCH's installed? If migration is still an issue on such a system? How does the refrigerant get into the crankcase when most of it is pumped into the cond. and receiver? Discharge line or ?

  3. #16
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    On a system with continuous pump down there really shouldn't be any migration but the crankcase heater obviously doesn't hurt anything. I imagine it helps when you shut down on safties and things. Occasionally you see a system that doesn't pump out during the defrost cycle it just shuts the comp off. It doesn't really help with this setup either as the heaters are going to be warmer than the little crank case heater.

    I actually had a set of zero zone reach in freezers that someone put a crankcase heater on and insulated the compressors(tin cans) It looked weird but it ran with the orignal compressors for years until the cases were junked.
    Last edited by dangpgt97; 05-24-2011 at 08:43 PM.

  4. #17
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    [QUOTE=JF254;10266912] what does everyone like better for r12 conversions hot shot or mp66..

    MP66 & stay away from Hot Shot on freezer apps.

  5. #18
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    Quote Originally Posted by dangpgt97 View Post
    On a system with continuous pump down there really shouldn't be any migration but the crankcase heater obviously doesn't hurt anything. I imagine it helps when you shut down on safties and things. Occasionally you see a system that doesn't pump out during the defrost cycle it just shuts the comp off. It doesn't really help with this setup either as the heaters are going to be warmer than the little crank case heater.

    I actually had a set of zero zone reach in freezers that someone put a crankcase heater on and insulated the compressors(tin cans) It looked weird but it ran with the orignal compressors for years until the cases were junked.
    I didn't think you needed them with a pump down system and i'm pretty sure it's impossible to migrate from the discharge line into the crankcase(suction) unless the valves are busted. But, you do bring up a good point on being out on safeties and LLSV wide open.

  6. #19
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    Quote Originally Posted by JF254 View Post
    nope have a ccrv already... they were worrying about liquid migrating in the off cycle.. gonna start the big one.. but what does everyone like better for r12 conversions hot shot or mp66.. from what I have read and heard the mp66 is better ??
    So is this a K body Copeland?
    The heater goes under the bottom and you have to loosen some screws. If you got a bellyband heater for a tin can that would make sense why you can't figure how to attach it.
    “If You Can Dodge A Wrench You Can Dodge A Ball”

  7. #20
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    What is the difference between defrost heaters and the fan adding heat to refrigerant?
    I'm asking this in reference to the migration question. If vapor going to the compressor during off-cycle ws a problem, wouldn't we have LL selonoids on a/c systems?

  8. #21
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    Quote Originally Posted by Joe Harper View Post
    What is the difference between defrost heaters and the fan adding heat to refrigerant?
    I'm asking this in reference to the migration question. If vapor going to the compressor during off-cycle ws a problem, wouldn't we have LL selonoids on a/c systems?
    No they have Crank Case Heaters
    Some just use the motor windings
    “If You Can Dodge A Wrench You Can Dodge A Ball”

  9. #22
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    I prefer Hot-Shot due to the fact that it's characteristics are pretty close to R-12. If you work on medium temp R-12 systems it works better than MP66 which keeps you from having to carry multiple bottles.

  10. #23
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    Quote Originally Posted by matts57 View Post
    I prefer Hot-Shot due to the fact that it's characteristics are pretty close to R-12. If you work on medium temp R-12 systems it works better than MP66 which keeps you from having to carry multiple bottles.
    I was always of the understanding that MP66 was a low temp R12 replacement, and MP39 was the better fit for medium temp R12.
    "The problem is the average person isn’t tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and it’s not in the movies they watch, and it’s not in the few books that they buy, they don’t get it" - Jack Canfield

  11. #24
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    Quote Originally Posted by matts57 View Post
    I prefer Hot-Shot due to the fact that it's characteristics are pretty close to R-12. If you work on medium temp R-12 systems it works better than MP66 which keeps you from having to carry multiple bottles.
    Problem with Hot Shot for low temp. is after -12* your going to be running in a vacuum. Not the case with R12.

  12. #25
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    Quote Originally Posted by markettech View Post
    I was always of the understanding that MP66 was a low temp R12 replacement, and MP39 was the better fit for medium temp R12.
    You're right when comparing those two, but the point I was trying to make was that by carrying Hot-Shot (which is a good replacement at both temps) you can eliminate one refrigerant bottle and recovery tank off your truck and still have a refrigerant that works quite well.

  13. #26
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    Quote Originally Posted by markettech View Post
    I was always of the understanding that MP66 was a low temp R12 replacement, and MP39 was the better fit for medium temp R12.

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