View Full Version : Defrost drain line (& heater)

04-06-2016, 09:53 PM
We have bought and put together a walk-in freezer/cold store, each have their own through-roof mono refrigeration unit.
Unfortunately when it was removed the wires were just cut, i've figured out most of it.

The defrost drainline appears (from pictures, it wasn't included) to be copper wound in a heating wire. It travels along the back wall from the chiller, through the freezer then forward to the front exrterior wall where it dropped to a sump/pump type thing. I will dispense with the later as i can just run to ground/drains (outdoor shed).

There doesn't appear to have been any fall on the pipe, if i put a fall in the new pipe, and insulate it can i get away without heating?

Both fridge units, have a drain point in the bottom tray, with a cable hanging out of the outlet, one is severed but one seems to end in a sensor, am i right? how can i replace it?

In addition i have the severed temp sensors that hang down through the roof, oddly they appear to splice to a shared multicore cable (using differing pairs of wire). I have no idea why this is (why would they need to travel any distance together?) or where to terminate the sensors on each unit.

I can provide pictures if anyone is feeling generous enough to help me

Many thanks

05-06-2016, 09:33 AM
I have another unknown part but i'm now suspecting it's a heated vent? Inset into front wall of freezer with tiny two core wire going to it. This wire seems almost identical to that hanging out of evaporator drain point.

SO if it is a heated vent, does that mean the evap wires are heater wires that go inside the first run of drain pipe before the externally wound heater wire starts

05-06-2016, 11:36 AM
pictures would be helpful.

05-06-2016, 01:45 PM
That would be a heated vent,the drain should be heated is it copper if so two options either put the heater tape inside the pipe for the part of it that's in the freezer or wrap it around it only heat it if it's copper don't insulate it of course it has to have a slight fall,pictures would be a great help as many as possible.

05-06-2016, 01:57 PM
Chiller evap and start of Drain line
http://i22.photobucket.com/albums/b316/GreenBeast999/Farm/Internal%20chiller_zpswyesizov.jpg (http://s22.photobucket.com/user/GreenBeast999/media/Farm/Internal%20chiller_zpswyesizov.jpg.html)

Here is the front of freezer with what I assume is a heated vent (just above door microswitch)
http://i22.photobucket.com/albums/b316/GreenBeast999/Farm/Front%20freezer_zpsyqxopwxj.jpg (http://s22.photobucket.com/user/GreenBeast999/media/Farm/Front%20freezer_zpsyqxopwxj.jpg.html)

This is the back of the chiller evap unit, with the unknown wire coming out, it appears sealed at the end (on the freezer one it is severed before)
http://i22.photobucket.com/albums/b316/GreenBeast999/Farm/20160605_100004_zpssmhr0shx.jpg (http://s22.photobucket.com/user/GreenBeast999/media/Farm/20160605_100004_zpssmhr0shx.jpg.html)

This shows the freezer evaporation where the drain line continues and is heated. All I have been provided with its the first 12" of the heater wire and the fused switch.

http://i22.photobucket.com/albums/b316/GreenBeast999/Farm/Internal%20freezer-2_zpszcotpdd9.jpg (http://s22.photobucket.com/user/GreenBeast999/media/Farm/Internal%20freezer-2_zpszcotpdd9.jpg.html)

05-06-2016, 01:59 PM
One thing that is really stopping me at least testing the unit is the temp probe. Where *should* it terminate, I don't appear to have an obvious cut wire near the pcb on the roof

05-06-2016, 07:26 PM
Ok figured what the probes are, they must be temp recording sensors for logging temps.
The unit appears to be working, just waiting for it to hit set point. I can't seem to change the set point but that's no big deal yet