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Thread: High Pressure Switches

  1. #1
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    High Pressure Switches

    I must ask someone’s opinion after being out of the refrigeration side of the business for a few years. I have a customer with several walk in freezers and coolers with automatic high pressure switches. When the head pressure gets too high the high pressure switch trips off and then automatically resets. The result is the units cycles on and off on high head pressure. Naturally, the high head pressure needs addressed. However, it seems to me the automatic switch seems like a bad idea. Does anyone agree with my thought?

  2. #2
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    I like the auto reset switch. When set correctly, the customer should notice a problem with the cooler/freezer while the high pressure safety control is cycling on/off. At the same time, it gives them a little refrigeration.

    I don't like the manual resets because once it trips...it creates an emergency call.

  3. #3
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    In the past I was very much in favour of manual rest high pressure switches, but as most system now have some level of electronics, (anti cycle, fault history) I have moved towards an auto-reset high pressure.
    If auto reset and limited controls are used, make such you have a large diff to ensure short cycling does not occur.

  4. #4
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    I use nothing but manual reset controls.

    Yes, they create a lockout condition but, without that, sometimes, you'd never know that there was a problem.



  5. #5
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    Manual resets
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Why is it that those who complain the most contribute the least?
    MONEY CAN'T BUY HAPPINESS. POVERTY CAN'T BUY ANYTHING

  6. #6
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    Quote Originally Posted by 2sac View Post
    Manual resets
    X2

  7. #7
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    Manual reset for job security

  8. #8
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    Any refrigeration tech here keep a list of defrost times for each customer? Place I used to work had the Exxon tiger mart gas stations as a customer.

    The attendents would see a rise in cooler temp and call the answering service in the middle of the night usually aand we had to respond. Most of the time it was the reach in going into defrost. I made a journal that referenced defrost timer settings with store numbers.

    Saved a few headaches.

  9. #9
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    Oh and remove head pressure switch and replace with igniter control circuit to launch multiple salvos of roman candles.

  10. #10
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    Quote Originally Posted by commtech77 View Post
    Any refrigeration tech here keep a list of defrost times for each customer? Place I used to work had the Exxon tiger mart gas stations as a customer.

    The attendents would see a rise in cooler temp and call the answering service in the middle of the night usually aand we had to respond. Most of the time it was the reach in going into defrost. I made a journal that referenced defrost timer settings with store numbers.

    Saved a few headaches.
    With most common timers, that's kind of silly.

    Power goes out for an hour and, unless you went and reset all of the timers to correct time of day, your notebook is useless.

    What we do is instruct all customers to wait a half-hour to 45 minutes after finding a unit warm before calling.



  11. #11
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    Thumbs down

    Quote Originally Posted by jpsmith1cm View Post
    With most common timers, that's kind of silly.

    Power goes out for an hour and, unless you went and reset all of the timers to correct time of day, your notebook is useless.

    What we do is instruct all customers to wait a half-hour to 45 minutes after finding a unit warm before calling.
    Timers were checked during PMs.

    You can imagine we thought of telling the gas station attendents to wait. You might as well try and have a conversation with the Slurpee machine.

  12. #12
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    Thread Starter

    High pressure switch

    When the automatic switches were in place the customer would ignore the fluctuating temperatures. However, after installing the manual switches the customer wanted to address the high pressure problem.

  13. #13
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    Quote Originally Posted by basprofessional View Post
    When the automatic switches were in place the customer would ignore the fluctuating temperatures. However, after installing the manual switches the customer wanted to address the high pressure problem.
    BINGO!

    Make 'em call you out.

    Only way to get it done sometimes.



  14. #14
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    Quote Originally Posted by commtech77

    Timers were checked during PMs.

    You can imagine we thought of telling the gas station attendents to wait. You might as well try and have a conversation with the Slurpee machine.
    Sorry, but I'm not responsible for their stupidity, and I charge extra to fix it.



  15. #15
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    Sounds like a " A/C is too cold fire up the furnace crew" working. They are good for business.

  16. #16
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    Quote Originally Posted by jpsmith1cm View Post
    I use nothing but manual reset controls.

    Yes, they create a lockout condition but, without that, sometimes, you'd never know that there was a problem.
    I LOVE that red button!!!!!!!
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  17. #17
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    Could be worse .. there's guys out there that find open pressure switches & say the switch is bad not even knowing what the pressure is

  18. #18
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    Quote Originally Posted by hvac wiz 79 View Post
    Could be worse .. there's guys out there that find open pressure switches & say the switch is bad not even knowing what the pressure is
    When in doubt, jump it out
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Why is it that those who complain the most contribute the least?
    MONEY CAN'T BUY HAPPINESS. POVERTY CAN'T BUY ANYTHING

  19. #19
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    Quote Originally Posted by hvac wiz 79 View Post
    Could be worse .. there's guys out there that find open pressure switches & say the switch is bad not even knowing what the pressure is
    I flipped on a guy once for telling me "It was tripping on high pressure, so I just adjusted the switch a little to stop it"





  20. #20
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    Quote Originally Posted by jpsmith1cm View Post
    I flipped on a guy once for telling me "It was tripping on high pressure, so I just adjusted the switch a little to stop it"


    Did you adjust it to 500 ?

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