Hubbard 480AEL

[WinterHill]

Hi

A few questions about a walk in freezer. The outdoor unit is a Hubbard 480 AEL-3 fitted to a 12 by 6 foot box from a vehicle.
This unit is cooling fine but when the compressor stops the indoor unit pours a load of water onto the floor!
Is this a defrost function?
How does the defrost system work?
Should the box have a drain running to the outside?
Should the indoor fan be running all the time or just when the outdoor unit is running?
Any help appreciated.
Thanks

[Brian_UK]

Firstly it sounds like a blocked drain.

You say "when the compressor stops", do you mean it has reached temperature or when the system is turned off?

Yes, there should be a drain to outside.

Indoor fan should run at all times to keep the air circulating and the sense the temperature. It should be off during defrost periods.

[WinterHill]

Thanks for the answers Brian.
When I say it stops I mean when temp is reached. At this point the motor and compressor outside stop and the indoor unit stops running. How long should the defrost period last?
I will fit a drain system shortly as the floor is becomming iced up inside.

[vtmpnate]

Your system's controller may be set to stop evaporator fan operation when the box temp reaches setpoint. Check the controller settings. The setting for evaporator fan operation can usually be changed so that the fan operates continuously even when compressor cuts out. If its a Danfoss EKC201, turn the system on, press the upper button for 2 seconds then scroll through the menu using the upper or lower buttons until you reach F01. You can change the setting by pressing the upper and lower buttons simultaneously. Change the fan operation from "off" to "on" during compressor cut-out using the same upper/lower buttons. Press both buttons simultaneously again to record your setting. It will blink 20 seconds before returning to displaying box temp. Hope this helped.

[WinterHill]

This is excellent advice and exactly what I needed. I will check the controller type and try your instructions.
But, how exactly does the defrost system work? Does it fill the system with hot gas or simlar as it seems to drip very quickly after the system stops running.
Many Thanks

[vtmpnate]

Good luck. I apologize though if I had given the impression that I'm familiar with the particular system that you are working on. I am not.

I was just guessing that the system you have uses a typical off-the-shelf controller from Danfoss. It may very well be the case... or not. Your system may be using another brand (in which case you may want to start another thread asking how to change parameters for that particular brand and model), or perhaps it is the manufacturer's proprietary/bespoke controller.

As for the defrosting method, I can only suggest that you check the piping/wiring/evaporator for hot gas solenoids, reversing valves, and electric heaters to find out what method it uses to defrost. hope this helps.


This is excellent advice and exactly what I needed. I will check the controller type and try your instructions.
But, how exactly does the defrost system work? Does it fill the system with hot gas or simlar as it seems to drip very quickly after the system stops running.
Many Thanks

[utc/tk foreman]

If the unit is pouring water out of the evap section after it reaches temp, it may be just the water draining off the coil that, while the fan is on, is being pushed against the coil. I see the same thing happen on alot of the straight truck units i work on in the spring and summer. Basically the force of the fan is keeping the dropplets of water from falling down and out of the coil.

[WinterHill]

Hi Again

I had a look at the controller today and both the evaporator and compressor were wired into the same point on the controller. I moved the evap wire from pin 5 to pin 4 and it now runs continuously. The compressor still starts and stops when required.
The controller is a Ektron REK33-0027 but I can't seem to find any info on the net about it.
Any ideas.

[Brian_UK]

Hi Winterhill,

This manual is for a different 'fridge but contains instructions for an REK33 so could be useful.

http://www.nisbets.co.uk/downloads/User_Manual_G590_G591_G592_G593_G594_G595_U629_U630_U632_U633_U634_U635_CC663_CABINET_ML_A4_v10.pdf

It's 6MB as it is in 6+ languages.

[WinterHill]

Thanks Brian

What would you reccomend for a defrost cycle. 20 mins every 6 hours?

[Brian_UK]

Probably a good starting point.

[alpha]

Hi, I haven't got my 480 information in front of me at the moment but from memory defrost settings are defrost every hour, defrost termination @15degC, max defrost cycle 15mins.

I would rather terminate defrost by temperature than time, depending on door openings and ice buildup I would tweak defrost interval to suit conditions.