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  1. #1
    Join Date
    Sep 2010
    Location
    miami,fl.
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    623

    r12 reach in cooler

    here is the story randell m#1020 its from 1993 2 door stand up cooler condenser on top. the original problem the extrernal overload burnt out comp tecumseh aea4440axa if i remember correctly. name plate rla 6.8 i put on a 1/4 - 1/3 hp supco hard start kit. trips overload in the hard start kit amps are in range 6.4amps. it looks to be because the compressor is on the high end and overload under rated jump out over load monitor amps unit comes down to 39 degrees amps come down to 6.1. i unplug it and order correct overload i tell the supervisor lets get current relay and start cap. he said no. only overload okay. (ive only been in this company 5 months not arguing with the boss) i tell him well i put my stubbies on and im running 20 over 140 78 degrees in the box 76 degrees condenser ambient i tell him i feel the suction line is cool but not enough to cool my comp. my super heat was something around 30ish i told him i feel it might need a tad of r12 to get a colder suction line in turn will cool my comp. he said oh no those pressures are high..( i wont argue never really worked on r12 i said okay.) it cools but takes a while. i installed new overload and checked unit it pullled down to 35 degrees after 45 mins with an empty box. seems long to me. it does have an r12 txv installed . a question if i pulled the charge 32 oz can i weigh in 134a using the same txv. since the temperatures are close??? i know i would have to 32 oz x .75=24 oz. another issue is once it reached temp the compressor will kick back on after 4 mins @ 40 degrees. then it overloaded on start up then kicked on with the 2nd try. 2 things either i can replace tstat or hope once they load it up with product it will hold temp better then stay off longer??? any input is appreciated sorry long post

  2. #2
    Join Date
    Oct 2011
    Location
    Chicagoland Area
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    4,626
    409a. 134a needs POE oil. Also sounds like it can't overcome the pressure difference at start up. I've said it before. If you have to change one start component change them all. I agree you are low on charge. A 78 degree box and 20psi suction doesn't add up. It is in the customers best interest to thouroughly check out a 20 year old unit and give them the option to repair or replace. Do a leak check before you throw anymore time and money into it.
    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
    Liberalism-Ideas so good they mandate them

  3. #3
    Join Date
    May 2004
    Posts
    12,028
    High amp, low suction, low on head with inside high temp... 45 minutes to bring down a two door box...

    I wouldn't worry about finding a leak or replacing the refrigerant. I would focus on replacing that compressor. Better still, the box if it isn't in great shape. It's loosing it capacity to pump. Additional refrigerant will kick it out on amps and you will still be left with a junk compressor.

  4. #4
    Join Date
    Oct 2011
    Location
    Chicagoland Area
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    4,626
    RLA is 6.8? Running at 6.4-6.1? Amp draw looks ok Dad
    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
    Liberalism-Ideas so good they mandate them

  5. #5
    Join Date
    Jul 2011
    Location
    Lehigh Valley, PA
    Posts
    447
    Sounds to me like a tired compressor. Or could some one else have already put R134 into this unit? I've seen how R134 works in older R12 units. Not that great and slow to cool down.

  6. #6
    Join Date
    May 2004
    Posts
    12,028
    Let's look at it from a different angle. Take the box age away.

    Compressor running amps close to RLA. Low head and suction. Stack more refrigerant against the TXV will increase amps and what is the first sign of a compressor failure? Start components failing.

    What ya think?

  7. #7
    Join Date
    Jan 2010
    Posts
    6,320
    [QUOTE=anthonyac1;15347361] im running 20 over 140 76 degrees condenser ambient super heat was something around 30ish i told him i feel it might need a tad of r12.

    140 head pressure in a 76* ambient ? I would take a good look at that condenser coil.
    Also is there really R12 in that system ? That would be real hard to believe unless it was still a sealed system.
    Try opening up that TXV and see what happens with your pressures.

  8. #8
    Join Date
    Oct 2011
    Location
    Chicagoland Area
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    4,626
    He's saying 6.1 at 39* At 32* you might lose another amp or so. I'd prove it out. He only replaced the overload so far. It's still possibe there's an issue with the relay or cap. I've had similar issues that could go either way. It could be proved out in an hour or two with minimal cost depending on the customer
    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
    Liberalism-Ideas so good they mandate them

  9. #9
    Join Date
    Sep 2010
    Location
    miami,fl.
    Posts
    623
    Quote Originally Posted by 2sac View Post
    He's saying 6.1 at 39* At 32* you might lose another amp or so. I'd prove it out. He only replaced the overload so far. It's still possibe there's an issue with the relay or cap. I've had similar issues that could go either way. It could be proved out in an hour or two with minimal cost depending on the customer
    the start cap rating that comp calls for was 145-175 it was actually reading 197 mfd. honestly i wanted to replace all start components but he strongly disagreed. when i think about it the current relay may have pitted contacts or going bad because in reality the start cap is stronger than required!

  10. #10
    Join Date
    Sep 2010
    Location
    miami,fl.
    Posts
    623
    the condenser coil is really really clean its in the lunch room of a bank. . they have a thin filter in front of it.

  11. #11
    Join Date
    Sep 2010
    Location
    miami,fl.
    Posts
    623
    [QUOTE=VTP99;15349011]
    Quote Originally Posted by anthonyac1 View Post
    im running 20 over 140 76 degrees condenser ambient super heat was something around 30ish i told him i feel it might need a tad of r12.

    140 head pressure in a 76* ambient ? I would take a good look at that condenser coil.
    Also is there really R12 in that system ? That would be real hard to believe unless it was still a sealed system.
    Try opening up that TXV and see what happens with your pressures.
    i called our office to look on the invoice to see what someone charged it with. supposedly we installed new r12 compressor like a year ago. they see one that states r12. i know we have r12 in our shop because on our refrigerant price list we have it listed. i would use it up over my 134a any chance i get.

  12. #12
    Join Date
    Sep 2010
    Location
    miami,fl.
    Posts
    623
    Quote Originally Posted by Dad View Post
    High amp, low suction, low on head with inside high temp... 45 minutes to bring down a two door box...

    I wouldn't worry about finding a leak or replacing the refrigerant. I would focus on replacing that compressor. Better still, the box if it isn't in great shape. It's loosing it capacity to pump. Additional refrigerant will kick it out on amps and you will still be left with a junk compressor.
    the fridge loooks ggod for its age. sits in the corner of the bank. [but now you mentioned it the insulation could have started to break down and loose its thermal capacity if im stating it right] basically not insulate the box properly. ill keep you posted if i have to go back.

  13. #13
    Join Date
    Jun 2003
    Location
    Tampa Bay, FL.
    Posts
    120
    I'm not familiar with Randell equipment but most full size double door coolers I've seen have a 1/2 hp compressor not a 1/3. Perhaps someone installed the wrong compressor last year.

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