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  1. #14
    Join Date
    Nov 2003
    Location
    South Carolina
    Posts
    1,167
    Someone mentioned the delay. Thats something i forgot about and i know they are on 404 systems but wasnt thinking about it for this r12. Fans start as soon as the compressor comes on with this system...will that keep me from reaching box temp?..I would think it would eventually catch up with itself even if a delay was bad..im pretty sure this unit doesnt have one.

  2. #15
    Join Date
    Apr 2002
    Location
    most of the time in the Philippines
    Posts
    1,211
    Is it air cooled? What is the temperature of the air entering the condenser? MP66- 15psig = +10, 148 psig = 98. Looks like evaporator is too high, condenser is too low. Knowing the TD berween the cooling medium entering the condenser and the condensing temperature would be helpful. My vote is inefficient compressor. The temp should eventually catch up with lack of a fan delay. An inefficient compressor diagnosis on a marginally sized unit [especially one with an MOP TXV] is difficult. If it's electric defrost without a pumpdown cycle, that is probably what killed the compressor. If the compressor is a semihermetic, you can always pop the head/valve plate and take a look. What are the compressor numbers? I looked at a Heatcraft quick select chart: a 6W x 6L x 8H box with a 95 ambient would need about 4522 btuh for average usage and 6570 btuh for heavy usage. These are based on an 18 hour run time with a 10% safety factor built in. That's for 288 cu. ft. of volume; yours is 128 cu. ft.

  3. #16
    Join Date
    Nov 2003
    Location
    South Carolina
    Posts
    1,167
    ambient going into the compressor was between 90 and 85 degrees...condensing unit is located directly on top of freezer thus recirculating much of the air. I never could get the head up. This is a hermetic compressor tecumseh unit. There is no solenoid thus no pump down cycle. Unit cycles off pressure switch but he pressure switch didnt seem to be set right..i never got that far because nothing was ever in sync. I think the only thing this unit was cycling off of was the defrost control to be honest. I should have gone ahead and told them the compressor needed to be replaced but i just wasnt confident enough in that diagnosis. I will take this as just a learning experience..I can say this I cannot stand r12 systems of any cooling medium and all the drop ins. The epa has made a sincere mess of this part of refrigeration and now they are targeting the hvac end of things with 22 replacements. I think i zoned in so much on these replacements that i failed to see the obvious here.

  4. #17
    Join Date
    Sep 2002
    Posts
    12,701

    Cynic asks - why so many idiots ?

    Like this -
    --------------------------------
    cynic
    ** Site Supporter **

    Registered: Jan 2002
    Posts: 1706
    chinese resturant ? what kind of shape is the box itself in ? mp66 is a little better than 409 for a freezer but I agree with dave thats if the box itself is in decent shape
    __________________
    If Darwin was right how come there are so many idiots roaming around ?
    -----------------------------------

    Well, it is my opinion that it is because we here in the US have become "The Worst Farmers On The Planet". On a farm you hoe the useless weeds and you cultivate the best crops.

    Here in the US we: Cultivate The Weeds

    What kind of student are you? Bright? Hard working? Focused? Good grades? Sorry - your parents make a few dollars too much - you're on your own.

    Or - are you a drug addict or drunk? Or have an IQ of 75? No worries then - we will take care of everything. Need food? A house? Transportation to see the doctor/dentist/podiatrist/pychologist that we will be providing free for you? How about some free legal work?

    Why we are not 100% subsidizing anyone's college education that scores say; 1300 + on their SAT's is beyond me.

    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  5. #18
    Join Date
    Apr 2002
    Location
    most of the time in the Philippines
    Posts
    1,211
    Normally, I like to see a pumpdown cycle on electric defrost, especially if the compressor is below the evaporator. In this case, you might consider adding a suction line accumulator when you replace the compressor. Call Tecumseh at 1-800-211-3427 and ask them to send you a copy of their Comprerssor Service Handbook. [free] Or, you can download it at http://www.tecumseh.com Also, call Dupont at 1-800-235-SUVA. Ask them to send you some p/t charts and also a couple copies of the Suva guide. The guide brochure has recommended LP switch setpoints for the various refrigerants. Let us know how you make out.

  6. #19

    Cool

    Sounds like the compressor was the problem in the first place. If you are drawing nameplate amps at the suction and discharge pressure you are running, I would suspect a broken discharge valve. To really check amps you need suction pressure, disch pressure and the performance curve for the comp. I do not know if this is what you have done, only making a guess

  7. #20
    Join Date
    Jul 2001
    Location
    Gold Coast of Connecticut
    Posts
    4,619
    IM going with what refer dude said.you needed a compressor and new gas!

  8. #21
    Originally posted by Freezeking2000
    IM going with what refer dude said.you needed a compressor and new gas!
    I said that 4 posts in on this thing.
    Hey cockroach, don't bug me!

    www.AskTheDiceman.com

    www.TheColdConspiracy.com

    www.Pennwood-HVAC.Com

    Bring Em Home....

  9. #22
    Join Date
    Jul 2001
    Location
    Gold Coast of Connecticut
    Posts
    4,619
    well dice you are faster than us!

  10. #23
    Originally posted by Freezeking2000
    well dice you are faster than us!
    Not at everything......
    Hey cockroach, don't bug me!

    www.AskTheDiceman.com

    www.TheColdConspiracy.com

    www.Pennwood-HVAC.Com

    Bring Em Home....

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