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claude11
13-06-2007, 06:52 PM
I have a 25 HP copeland , using HP 80 , The suction is 5 psi . the temperature is 33 F on the suction side at the compressor ( I can't get at the evaporator without removing product) . the discharge pressure is OK but the temperature is a little high . I was going to open the TX valve a little more . should I check anything else before I start crawling over 10,000 pounds of half frozen fish.

Lowrider
13-06-2007, 08:57 PM
HP 80 is R402a, 5 psi = 0,3 bar, 33F is 0,5 dgrC. So the superheat is 42K!

How high is the discharge temp and what pressure? Liquid line temp and subcool?

Perhaps lacking refrigerant?

mohamed khamis
14-06-2007, 08:40 AM
I have a 25 HP copeland , using HP 80 , The suction is 5 psi . the temperature is 33 F on the suction side at the compressor ( I can't get at the evaporator without removing product) . the discharge pressure is OK but the temperature is a little high . I was going to open the TX valve a little more . should I check anything else before I start crawling over 10,000 pounds of half frozen fish.

Hi claude11

U have an oil separator in ur system or not? ...if it is not, it may sound there is an excess amount of oil in ur system causes some blockage in the TXV and inefficient operation of the evaporator as well the raising in discharge temperature. Otherwise check the subcooling, the filter-drier and receiver. I wish it could help

Cheers

lana
14-06-2007, 09:04 AM
Hi there,

Before adjusting the TEV check the followings :
Super heat
Sub cooling
LP
HP

If low pressure is low and super heat is high and sub cooling is OK then check for any blockage in the liquid line first. If any thing is OK then it is the TEV.

If low pressure is low and super heat is high and sub cooling is low then there is lack of refrigerant.

If low pressure is low and super heat is low then check your evaporator. Look for anything which prevents evaporation, like fans are working , frost ,...

Hope this helps
Cheers