Kevry open display case freezing up

[mastercheif602]

Have a open display case that has the air curtain on it.

Unit is 404a

Suction 55
Suction line 54
superheat 34

discharge 280
line temp 108
subcooling 6

Has a sporlan temp contol on it. Set unit to 30 keeps things at 39 to 40.

Unit will run for a week then freeze up. Does anyone know about sporlan electronic temperature controls.

[Gary]

Being from the usa, let's assume F and PSI. Can we also assume TXV system? Is this a single compressor system or connected to a rack? Is the condenser outdoors?... or under the cabinet?... or perhaps it is water cooled?

We can't see it from here. Paint us a picture.

[mastercheif602]

Glad you chimed in.

txv, and condenser is under unit and it is inside, and sorry psi and f

[mastercheif602]

this is what it looks like

http://www.kevry.com/html/product_page.php?prod=29

[Gary]

If we assume 75F room temperature, then the SCT is running about 39F over ambient. So I'm thinking the condenser is probably dirty, but then... 75F room air is just an assumption. It would be good to know the condenser air in and air out temps. If cleaning the condenser doesn't do it, then it probably has a leak.

[mastercheif602]

condenser is clean, the place is about 70f. Did not check the in out temp will do and let you know.

[jimmylcoleman]

Faulty Evaperator fan can cause the freeze up, as well as a Low charge. I've seen the fans start then stop. Usually catch one going bad by accident. Clogged condensors are big in my buisness...where the cutomers doesnt want dust blown anywhere around the food on display.

[jpsmith1cm]

Good grief. I had a case haunt me for months with ice up problems off and on.

Store would shut it down to defrost it 3 or 4 times, then call us.

We finally tracked the problem down to a faulty defrost controller.

By "Sporlan temperature controller" Do you mean the Omnistat or a different one?

Check everything on the refrigeration side twice, THEN, if you find nothing, replace that controller.

[fridge doctor]

Any possibility that an evap fan may have been changed recently? if so check rotation and blade attitude.