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  1. #53
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    Quote Originally Posted by hvacskills View Post
    what does this mean ?

    did your amperage " peg out " ? did it sound as if the compressor was seizing ?
    Amp probe was on 15 amp scale setting when it pegged, I’m guessing it went to locked rotor amps.

  2. #54
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    That Ranco control is a Temp Control so once the unit cycles off the Temp control might be bringing the comp back on before the press has a chance to equalize thus causing to comp to "seize up". Thats where a loaded box will have longer off cycles allowing the equalized press to not seize the comp.

  3. #55
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    Quote Originally Posted by hvacskills View Post
    I apologize I was working earlier and did not get a chance to take a close look at your numbers ......

    on your first run ...... I am getting :

    10.9 psi 3.43 degrees

    116.2 psi 99.60 degrees

    with a liquid line temperature of 114 degrees


    those numbers are pointing to you being undercharged due to lack of subcooling and just being low in general, lack of subcooling also should eliminate a restriction .....

    what was your superheat ?

    it is POSSIBLE that because you are undercharged you did not have enough cool refrigerant coming back to the compressor to cool it down, especially dropping a " hot box " in 89 degree weather, it is POSSIBLE that is why you tripped on overload on the second run, maybe ....... it is also possible that the overload just tripped because it is old and got very warm ... did the compressor feel warm, did it feel warm enough to trip the overload ? possible that over the last few weeks or months or however long this unit has had its problem, running in a vacuum, the compressor got pretty hot and wore on the overload, but the overload is 70 years old ? ? ? ? relays and overloads DO HAVE THEIR LIFE SPAN !

    kinda curious about your 140 psi head pressure on the second run, I got 140 psi being at 112 degrees, that is 23 degrees above ambient, which seems low, I would think a unit that old would run around 30 degrees above ambient, so is 140 psi high if you were undercharged ? that is a close one ......

    89 + 30 = 119 degrees, 119 degrees translates to 155 psi ........ IF 30 degrees above ambient is your normal operating temperature then I would expect to see around 155 psi head pressure in 89 degree weather when properly charged and at box temperature ....

    nice job on the fan shroud, can I see a picture of it ?

    this unit should be charged by superheat, as I mentioned earlier .....

    good job getting your numbers and hanging in there and thanks for getting back to us ....

    curious, how deep of a vacuum did you pull ? also, did you use nitrogen when doing your triple evacuation ? : )

    the " pegged " is concerning .... if the amperage is normal and the compressor has cool refrigerant coming back to it to cool it down I would suspect a possible faulty overload, or maybe the compressor is bad .... it is not uncommon to have multiple issues with a unit ....
    I did use nitrogen in between the triple evacuation and was pulling it down to 200 microns. I will post photos when finished, I had an old shroud from a vending machine deck, perfect fit. I do believe it’s stil low on refrigerant.
    I pulled the refrigerant again and pressurized to 200 lbs overnight. Headed out to work on it after breakfast. I want to recharge from scratch bye superheat per your advice. Most of the decks I work on are not in the cases so trying to charge bye superheat doesn’t work for me, so I weigh in most decks (used in vending machines). Thanks again.

  4. #56
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    Quote Originally Posted by wec1951 View Post
    I did use nitrogen in between the triple evacuation and was pulling it down to 200 microns. I will post photos when finished, I had an old shroud from a vending machine deck, perfect fit. I do believe it’s stil low on refrigerant.
    I pulled the refrigerant again and pressurized to 200 lbs overnight. Headed out to work on it after breakfast. I want to recharge from scratch bye superheat per your advice. Most of the decks I work on are not in the cases so trying to charge bye superheat doesn’t work for me, so I weigh in most decks (used in vending machines). Thanks again.
    the ole quadruple evacuation, even SWEETER !

    should be good at 200 microns and a new liquid line filter drier

    nice on the fan shroud !

    POST 19 says with a 12 degree coil you measured 22 degrees suction line temperature 8 " from the compressor, use that same place again, looks like superheat is tracking around 10 just like we were taught in school, make sure you are insulated


    this is ABOUT what you should be seeing, box temperature followed by superheat

    box
    temp

    45
    44
    43
    42
    41
    40 10 ish
    39 10 ish
    38 10 ish
    37 10 ish
    36 10 ish
    35 10 ish
    34 10 ish
    33 10 ish
    32 10 ish
    31 10 ish
    30 10 ish
    29 0 TARGET

    as mentioned

    if the coil floods ABOVE 29 box temperature you are slightly overcharged
    if the coil floods BELOW 29 box temperature are slightly undercharged

    DO NOT ALLOW COMPRESSOR TO RUN WITH FLOODED COIL

    what are the low / high ambient temperatures this box is normally exposed to ? we can fine tune the charge for those conditions seeing how you may be charging it in a slightly higher temperature ?

    I am suspecting a possible bad overload, maybe .... hope it is not the compressor
    Last edited by hvacskills; 08-10-2018 at 08:22 AM.
    TYRANNY

    The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether of one, a few, or many, and whether hereditary, selfappointed, or elective, may justly be pronounced the very definition of tyranny.


    the refrigerant sacrificed some of its soldiers to boil off so they could cool themselves

    https://www.youtube.com/watch?v=N5ij89gyMcY

  5. #57
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    Quote Originally Posted by hvacskills View Post
    the ole quadruple evacuation, even SWEETER !

    should be good at 200 microns and a new liquid line filter drier

    nice on the fan shroud !

    POST 19 says with a 12 degree coil you measured 22 degrees suction line temperature 8 " from the compressor, use that same place again, looks like superheat is tracking around 10 just like we were taught in school, make sure you are insulated


    this is ABOUT what you should be seeing, box temperature followed by superheat

    box
    temp

    45
    44
    43
    42
    41
    40 10 ish
    39 10 ish
    38 10 ish
    37 10 ish
    36 10 ish
    35 10 ish
    34 10 ish
    33 10 ish
    32 10 ish
    31 10 ish
    30 10 ish
    29 0 TARGET

    as mentioned

    if the coil floods ABOVE 29 box temperature you are slightly overcharged
    if the coil floods BELOW 29 box temperature are slightly undercharged

    DO NOT ALLOW COMPRESSOR TO RUN WITH FLOODED COIL

    what are the low / high ambient temperatures this box is normally exposed to ? we can fine tune the charge for those conditions seeing how you may be charging it in a slightly higher temperature ?

    I am suspecting a possible bad overload, maybe .... hope it is not the compressor
    I believe the client is using it in his home so 75*f

  6. #58
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    Quote Originally Posted by wec1951 View Post
    I believe the client is using it in his home so 75*f
    I just put a couple of cases of water in unit to put a load on it. Cut in 36*f, cut out 30*f
    Unit has been running for several hours now without a hiccup. Pulled the nitrogen, pulled deep vacuum 200 microns, charged to superheat and now waiting to see where we are. Trying to tune in that superheat is time consuming for sure. Box temp at 30*f and superheat around 8-9*f so far. I will follow up with you later.

  7. #59
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    Quote Originally Posted by wec1951 View Post
    I just put a couple of cases of water in unit to put a load on it. Cut in 36*f, cut out 30*f
    Unit has been running for several hours now without a hiccup. Pulled the nitrogen, pulled deep vacuum 200 microns, charged to superheat and now waiting to see where we are. Trying to tune in that superheat is time consuming for sure. Box temp at 30*f and superheat around 8-9*f so far. I will follow up with you later.
    lol .. it is definately time consuming FOR SURE ....

    whats your current ambient ? if you are around 85 ambient CAREFULLY BARELY flood the coil around 30 degree box temperature and call the charge good to go ...

    IT SHOULD FLOOD, however if you are adding refrigerant and it dont want to flood and your high side and low side pressures keep rising I wouldnt add anymore FREON then just use your best guess ... possible there may be one of those bulb type things on the evaporator outlet that accumulate liquid FREON to prevent liquid FREON from coming back to the compressor ...

    dont forget to adjust your thermostat back ...,
    Last edited by hvacskills; 08-10-2018 at 02:25 PM.
    TYRANNY

    The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether of one, a few, or many, and whether hereditary, selfappointed, or elective, may justly be pronounced the very definition of tyranny.


    the refrigerant sacrificed some of its soldiers to boil off so they could cool themselves

    https://www.youtube.com/watch?v=N5ij89gyMcY

  8. #60
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    if it dont want to flood just go as low as you can on your evaporator temperature while still maintaining your 8 - 9 degree superheat where you are reading it now ... and that I would do to around 29 degree box temperature ...
    TYRANNY

    The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether of one, a few, or many, and whether hereditary, selfappointed, or elective, may justly be pronounced the very definition of tyranny.


    the refrigerant sacrificed some of its soldiers to boil off so they could cool themselves

    https://www.youtube.com/watch?v=N5ij89gyMcY

  9. #61
    Join Date
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    Is there a drain at the bottom of the box's interior?
    If so; does it have a valve in the drain line?
    Are the interior's evaporator coils all located low in the 'chest'?

    Many of those chest-type soft drink coolers were designed to cool a water bath system. This provides faster cooling of the warm product added, serves as a heat-sink storage of the 'cold', and eliminates short cycling. The stat senses fluid temperature which would typically be about 34-35º F.

    Water level is sometimes marked on the inside but if not; adjust it to just below the level which will prevent the bottles from floating or becoming unstable.

    PHM
    --------



    Quote Originally Posted by wec1951 View Post
    What should evaporator temperature be around when box is at set temperature? Currently at 12 degrees and frost on suction line back to compressor. Box cut in 38 f , cut out 33 f.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  10. #62
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    Did you replace the condenser fan shroud ?

    It may been cycling that O/L for a long time. Does it have amp rating printed on it?

    PHM
    --------


    Quote Originally Posted by wec1951 View Post
    Pulled the r12, removed filter drier, ran slow stream of nitrogen through the system, installed access port on liquid line, installed new filter drier, ran static pressure test, did a triple evacuation, added 8oz r12, started compressor and charged to frost back. 33*f box temperature, 7* f evaporator coil temperature, 10.9 psi suction, 116.2 psi liquid, 114*f liquid line temperature, ambient 89*f, pulling 3.8amps.
    System ran through a cycle and then compressor tripped on internal overload. Pressure stabilized, compressor started and pulled down to 16 psi suction then tripped again and the head pressure was climbing much quicker than the suction was dropping (head pressure 140 psi)
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  11. #63
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    It's doesn't work like that - the compressor O/L - which is external - only stops the compressor. The condenser fan is left running.

    PHM
    --------


    Quote Originally Posted by wec1951 View Post
    At start up it was drawing 4.2 amps and as the box cooled it dropped down to 3.8 amps. But then it pegged out and tripped on “internal overload”, the external overload never tripped (condenser fan motor still running).
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  12. #64
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    That unit should have a semi-hermetic compressor. Change the oil - it's about due for an oil change - use POE - and charge the unit with R-134.

    Or; that's what I would do.

    PHM
    ----------


    Quote Originally Posted by hvacskills View Post
    if I was to replace the deck I would probably try to go R417c, that refrigerant operates pretty closely to R12 with a low temperature glide, however I would not even begin to be able to tell you how to match up that unit or if R417c would be your best choice, pecmsg or ICE would probably be able to point you in the right direction regarding that .... might be better off just replacing it and being done with it .... sure got their moneys worth .....

    you could stick R12, but I heard something about not being allowed to use R12 in a replacement but I have absolutely no idea the truth to that, sure somebody out here knows ....

    you did the ole triple evacuation, sweet !
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  13. #65
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    Quote Originally Posted by Poodle Head Mikey View Post
    That unit should have a semi-hermetic compressor. Change the oil - it's about due for an oil change - use POE - and charge the unit with R-134.

    Or; that's what I would do.

    PHM
    ----------
    thinking the unit had intermittent icing of the capillary tube, think OP got that problem solved, now verifying the compressor is good ...
    TYRANNY

    The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether of one, a few, or many, and whether hereditary, selfappointed, or elective, may justly be pronounced the very definition of tyranny.


    the refrigerant sacrificed some of its soldiers to boil off so they could cool themselves

    https://www.youtube.com/watch?v=N5ij89gyMcY

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