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  1. 07-08-2012, 10:58 PM #1
    ir.hvac
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    Frown Low oil pressure lockout on conventional cast iron WI grocery freezer

    Looking for some help on a conventional cast iron compressor, ie grocery freezer that spewed its charge everywhere on the roof from the condensor. Currently have quote in place for condensor replacement, but customer wants unit running till approved. Added 2 gallons oil and still going out on low oil lockout. Reset then it runs for about 5 minutes and fails. Running about 30 psi on oil pressure from pump w/10 psi on suction. Even pumped down compressor, closed off, contained and checked oil transducer filter. What gives?
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  2. 07-08-2012, 11:04 PM #2
    ir.hvac
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    HVAC guy still trying to learn a lot of bells and whistles on Refrigeration, ie rack systems and such. Any help would be greatly appreciated.
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  3. 07-08-2012, 11:24 PM #3
    VTP99
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    What make is the oil control ?
    Sentronic ?
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  4. 07-09-2012, 12:01 AM #4
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    Six
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    Quote Originally Posted by ir.hvac View Post
    Looking for some help on a conventional cast iron compressor, ie grocery freezer that spewed its charge everywhere on the roof from the condensor. Currently have quote in place for condensor replacement, but customer wants unit running till approved. Added 2 gallons oil and still going out on low oil lockout. Reset then it runs for about 5 minutes and fails. Running about 30 psi on oil pressure from pump w/10 psi on suction. Even pumped down compressor, closed off, contained and checked oil transducer filter. What gives?
    Cast iron comp ? Im guesing its a copeland semi hermetic. Provide the model # and there are some super sharp refrigeration guys that could give you the original oil charge and the oil pres.

    If its a sentronic I think cut out is around 8 and cut in is around 16. There should be a red and green LED thst can give you an indication of either low oil or oil pressure fluctuations.

    Also the correct way to check oil pressure is with crank case pressure, not suction.
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  5. 07-09-2012, 06:13 AM #5
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    jpsmith1cm
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    Check the pump intake screen.
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  6. 07-09-2012, 07:08 PM #6
    VTP99
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    Cut-Out 7-9 PSID ( pounds sq. inch differential )
    Cut-In 12-14 PSID
    Time Delay 120 seconds +or- 15

    If your getting 20 PSID ( 30-10 ) you should not be tripping out.
    As (6) said you should be checking at the crankcase.

    Sentronic speaking
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