Freezer Icing Up

[wackiejackie88]

Hey everyone, I own a Traulsen 3-door freezer in my bakery. I have a problem with ice building up in the evaprator hump and it strats to hit the blower motor after a few days. I called Traulsen and spoke to their techs and theyre all baffled.

Now, heres a little history on the unit. It was bought in 1996 and we've had problems since day-one. We made it a remote unit because of all the noise it made. My tech can't seem figure out the problem either. So I though I would have a crack at it...here are some of the problems i took care of. The evaportor hump cover was never put on properly and wasn't screwd down. The pipe for the drain pan leading out of the evaporator hump didn't have putty around it. The air duct in the freezer was not put up again after the ice forced it down. Two door gasket were leaking a little. Now all these problems have been resolved and i still have ice build up.

After all these repairs i still got the ice build up and it builds up quick (2-3 days than it starts to hit the fan motor). Today i spoke to a Traulsen tech and asked him if he though that maybe we had condensation because of the defrost cycle being too long...he said it could be a possibility. He instructed me to put two more pins in the defrost timer (total of 6) for 20-25 instead of 32 minutes where it is now. Note: the Traulsen techs asked if the freezer went into deforst we established that it did because the evaporator never had any ice on it.

I also asked if maybe the drian line leading to the basement could be bringing warm air into the evaporator hump...he said its possible and instructed me to put a p-trap on the drain line.

If any of you guys or gals have any idea on whats wrong please let me know. Any information is much apprecaited. Thanks

-Jack

[PaulZ]

Hi Jack
There a re a few reasons an evaporator can ice up.
Has your tech checked the refrigerant charge.
Has he checked the superheat of the TX valve if it has one, if it is a capillary system is it partially blocked.
Is the drier partially blocked.
Is the air getting into the cabinet from somewhere.
Is the air flow too low or restricted, partially blocked evaporator.
Is the fan going the right way or the right blade for the direction of the motor.
If there are multiple fans is there one not running, it may look like it is but could be going backwards because of the other fans drawing the air through this fan and not the coil.
Let us know what is found.
Paul

[wackiejackie88]

Hey Paul, Thanks very much for the reply I will mention what you said to my techs and the techs at traulsen. The thing is the evaporator is not icing up its the box where the evorator is on top of the freezer the ice grows beneath the evaporator and drain pan around the perimeter of the box. I assumed and so did the techs at trualsen that it was a condenstaion problem. But i will mention what you said to them. If you have any more info please let me know. Thanks agian.

-Jack

[PaulZ]

Hi Jack
If the evap has no ice most of the previous info won't apply except for the air getting in. What type of defrost does the evap have, electric or hot gas?
If it's electric get all the heater elements checked and make sure there is an element at the bottom of the evap and one in the drain tray.
Paul

[fridgey]

Hi Jack,

Also check the if the drain line has a drain line heater and if it does is it working properly. If there isn't one or it's not working the drain will be blocked frozen with ice. When the system goes on defrost the water can't drain away causing ice to build up in the drain pan, and then hits the fans like you say.
Hope this helps.
Cheers

[philfridge]

The thing is the evaporator is not icing up its the box where the evorator is on top of the freezer the ice grows beneath the evaporator and drain pan around the perimeter of the box.

Sounds like system short of gas freezing at evaporator inlet of capillary line/ TEV. You need to get the basics sorted first before you look eleswhere