Open top meat bin not working right or is it

[mastercheif602]

Came across an open top meat bin. It has two doors as a pass through. The unit was not working. Found it was off on head pressure switch. Rest, head pressure was very high. Clean The condenser and the watched it run.

The unit has a pressure switch to control the box temp.

It is medium temp and I set it to cut in at 62psi and out at 40 psi. The unit is a r22.

Did my split on the condeser and got a 21 degree split on that.

What is troubling to me is

my super heat was at 19degrees and my sub cooling was at 2 degrees F.

I waited a few to let box cool down then checked it again once it got closer to temp

Super heat was at 10 degrees f, and the sub cooling was at 21 degrees.

Is this unit over charged. The ambient air is like 75 degrees.

[Gary]

Yes... but not a lot.

The subcooling should be max 15F.

[mastercheif602]

I thought that my sub cooling should be at or around 2 to 5

[Gary]

I thought that my sub cooling should be at or around 2 to 5

Nope... 10-15F.

The extra subcooling raises the head pressure, which adds to the operating costs and makes it more likely to kick off on the HP control on a hot day.

[mastercheif602]

why would I want to kick out on hp, should I make the subcooling lower

[Gary]

Above 15F is extra. The 21F subcooling you currently have is the extra I was referring to.

I would slowly remove refrigerant until the subcooling is 15F.

[mastercheif602]

question: is 15 the kind of subcooling I should have on all medium temp equipment. Does this apply to a Walk in cooler also.

[Gary]

Yes... it pretty much works for all TXV systems.