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Milk Coolers Again!

Hello all,

If anyone has missed some good refrigeration questions, I am trying to overcompensate today. Actually I tried yesterday but the message got canned when the kiddos got access to the puter!

Mueller milk tank units are what we are working on. M# A51-HPF, S# 85D-0003-51C. Tank 1 was not cooling down quickly so we looked at the condenser on the right side(was not sweating like the other unit). These are the readings we got: milk temp-49° F, 48 lbs low, 170 liquid. According to the manual we have, the suction pressure should be 55-60 lbs. Added R-22 per manual. Milk temp now 46°F, 54 lbs low, 175 hi. Checked subcooling because we have a subcooling valve(sensing bulb on the outlet of condenser). According to manual we should have 10° subcooling, we had fluctation from 2 to 8° F. Added more 22. Milk now at 42° F and 52 lbs low, 170 hi, subcooling still fluctuating. I am recommending replacing the subcooling valve. Any thoughts??

Tank 2 the next day(3-16) and 36° ambient. Same model condensers. Right hand side=milk temp 55°, 65 lbs lo, 140 hi, subcooling 15-20°. Discharge line temp 107°. According to the book anything below 150° discharge line temp is overcharged.

Left hand side= milk temp 55°, 55 lbs low, 140 hi, subcooling 20-25°. Discharge line temp, 134°.

Both units on the same tank. I called the supplier we buy parts for and got a service tech to call me back to run these numbers buy. He tells me that they don't really mean anything to him. If he is having trouble with a unit, he "recovers" with the comp. and weighs the charge. Assumes that there is 3 lbs in the system and recharges accordingly. Any thoughts!

I like the idea of recovering the charge to check for accuracy, but there seems to be more going on than just "charge" issues.

It is getting warmer!
Don in MO


  • dmy hvac
    dmy hvac Member Posts: 33

    hi just a couple things you can check.when you say tank 1 tank 2 is that two seperate tanks?or is 1 1/2 of tank 1 compressor and the oyher 1/2 another?with r22 you should always mantain atleast a 200psi head pressure you may need to install a fan cycle switch to keep pressure adove 200 you can also check super heat should be between 4 and 7.also do you have bubbles in sightglass? txv needs full column of liquid to work properly.does compressor have a service valve on suction line on compressor so you can check suction should pull your guage to atleast a 20 inch vac then shut unit down it should hold vac if doesent valves are shot in comp i replace alot of them with similiar problems you are having id try fan cycle switch and filling till full sight glass and checking super heat
    [email protected] Member Posts: 139
    Paul Mueller HiPerForm System

    Thanks for the reply!

    This is a flooded evap. with a SUBCOOLING TXV. You measure subcooling out of the cond. coil. The sensing bulb is on the outlet of the cond. coil. According to the manual the valve is to maintain 10° subcooling. No super heat measurement is taken for system set up that the manual stats. No liquid line site glass. The valve is a sporlan brand, need to check their website and see if it is on there.

    Tank 1 is seperate and has two condensers. Tank 2 also has two condensers. They have Copeland 5 HP comp. Cnrn-0500 model numbers.

    They do have fan cycle switches. Two cond fans, one on all the time and one cycles. CI250, CO 150, factory settings. The system has no reciever, but has an accumalator with the liquid line going thru it for subcooling.

    Anyone familiar with Mueller products and the HiPerForm?

    I am contacting them to get set up as a dealer and try to get factory training.

    Don in Mo
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