Changing out AB Cold Machine Fan

[zboss]

No ... No water pump. The cold /frost goes right up to the top 90% of the evaporator.

It wasn't cooling at all when we bought the boat so we had a tech look at it... He refilled the refrigerant and said the cap hadn't been replaced correctly. Was like $35 bucks for his visit and it's kept things frozen ever since. I have not noticed the level change since it was fixed.

We have the compressor set at 3000 vs the top speed of 3500.

I want to add a 12 volt small fan to tumble the fridge air but I'm not sure where to wire it.


Sent from somewhere other than where I want to be!

[Doug Brown]

Hi - on both of the units I have had - one from 20-years ago and the current one that is about 5-years old, the AB fan was out in the open and you could see the two wires going into the fan motor (22-ga (???) red and black).

Remove fan, snip wires, install butt connectors, put Hella fan wires into butt connector to make sure the Hella fan is pushing/pulling air in the direction you want, and then finish crimping wires into the butt connector.

If you leave the new wires to the Hella fan a little long you can install the Hella fan a couple of inches away (I usually have it about 4 to 6-inches away) so you get a rear blast of cooling air over the entire thing - fins, compressor body and electronic package.

The only other real "trick" to AB units is have a large cool air inlet source for the Hella fan to draw from and a real big air exit so all the hot air gets blown out of the AB compartment. Think "big" so the hot air has somewhere to go and doesn't get "trapped" around the AB unit.

[Stu Jackson]

Originally Posted by zboss

I want to add a 12 volt small fan to tumble the fridge air but I'm not sure where to wire it.

Many folks have found it easier to buy a small battery powered (AAA or C cell) fan and move it around inside the box, rather than hard wiring it into the boat 12V system.

Your boat, your choice.

[zboss]

Originally Posted by Stu Jackson

Many folks have found it easier to buy a small battery powered (AAA or C cell) fan and move it around inside the box, rather than hard wiring it into the boat 12V system.

Your boat, your choice.

Great idea.


Sent from somewhere other than where I want to be!

[SV THIRD DAY]

The Danfoss Electronic Controller output that powers the condensing fan is 0.5A, so you have to be careful in just connecting another small fan to that circut because if the Controllers senses an over-Amp situation on the fan...bingo....unit trip off and Red LED Flashing error light.

The battery fan is a good idea or you can use a 12v relay tied into the fan circut that trips on an additional fan either in your box, to vent the mounting location of your compressor unit, or to run a Bar is Open Light...you get the picture.

If you want to install an air circulation fan in the box, a nice way is to run a seperate 12v circut through a thermostat so that whenever your box hits the set-point the circulation fan comes on to help equalize your box temps.

Here's a link to the 12v DC fan we use on the Condensing unit:
http://www.mechatronics.com/pdf/MD1238.pdf
These suckers are low amp and run for years and years and years...

They have lots of good DC fan choices:
DC axial fans for electronics cooling from Mechatronics, Inc.
We use a little

[onestepcsy37]

Originally Posted by Stu Jackson

FWIW, the fuses on our Cold Machine (fridge not freezer) are 10A. The builder put a 15A in the electrical panel, but the one on the unit is 10A. How do I know? The original unit, still on our boat, had a backup fuse in a small plastic bag right at the electronic module.
.

You got me worried stu. When I installed my ab cu200 ten years ago I followed the instructions religiously, including a 15 amp breaker on the positive lead going in to the unit. Now you are saying there is a 10 amp fuse on the ab unit too? Where is it? Thanks for the info...

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

[onestepcsy37]

Originally Posted by Stu Jackson

Many folks have found it easier to buy a small battery powered (AAA or C cell) fan and move it around inside the box, rather than hard wiring it into the boat 12V system.

Sounds like me. Mine runs on 2 D cells. But if I wasnt so damn lazy I would hard wire a small 12v fan from the control module...

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

[colemj]

Originally Posted by SV THIRD DAY

The Danfoss Electronic Controller output that powers the condensing fan is 0.5A, so you have to be careful in just connecting another small fan to that circut because if the Controllers senses an over-Amp situation on the fan...bingo....unit trip off and Red LED Flashing error light.

The battery fan is a good idea or you can use a 12v relay tied into the fan circut that trips on an additional fan either in your box, to vent the mounting location of your compressor unit, or to run a Bar is Open Light...you get the picture.

If you want to install an air circulation fan in the box, a nice way is to run a seperate 12v circut through a thermostat so that whenever your box hits the set-point the circulation fan comes on to help equalize your box temps.

Here's a link to the 12v DC fan we use on the Condensing unit:
http://www.mechatronics.com/pdf/MD1238.pdf
These suckers are low amp and run for years and years and years...

They have lots of good DC fan choices:
DC axial fans for electronics cooling from Mechatronics, Inc.
We use a little

The Danfoss controller has a 0.5A circuit for its normal fan as well as an additional 0.5A circuit for an auxiliary fan.

Rich, those fans you list draw 0.85-2.5A. Are you using them with a relay? Also, those are very noisy fans - 52-62dba! However, they do move a lot of air volume - actually seems a bit more than needed.

Our AB came with two fans (we have the optional ducting kit) that each move 69cfm, draw 0.16A and have 32dba noise levels. One recently failed and I replaced them both with fans that move 74cfm, draw 0.11A and have 15dba noise levels: SilenX EFX-12-15 Case Fan - Newegg.com

Fans can add a lot of noise to the compressor - it is virtually silent without the fan. If your compressor is located in living areas that are not sound-isolated from it, a quieter fan can help.

I don't understand how a 6" Hella fan is advantageous. One needs the fan to force cool air through the condensing coils - not just blow on the unit itself. It would be better to add another fan in a push-pull arrangement like ours is, or to use it to exhaust air out of the compartment, than to just put a large fan in the compartment to blow air around.

Mark

[colemj]

Originally Posted by colemj

Our AB came with two fans (we have the optional ducting kit) that each move 69cfm, draw 0.16A and have 32dba noise levels. One recently failed and I replaced them both with fans that move 74cfm, draw 0.11A and have 15dba noise levels: SilenX EFX-12-15 Case Fan - Newegg.com

Fans can add a lot of noise to the compressor - it is virtually silent without the fan. If your compressor is located in living areas that are not sound-isolated from it, a quieter fan can help.

Just an update on living with the new fans I mention above. These things are completely silent. Our compressor is mounted in a living area with an air exchange grill in the compartment. We were always able to hear the low hum of the compressor fans when running. We cannot hear anything at all with these new fans - not even when I put my head in the compartment right next to the compressor.

If anyone needs a cheap update to their fans, I recommend these.

Mark

[onestepcsy37]

Thanks for the URL. Its about the same price as the one I bought at the junk shop. Will get one for a spare.

My fans are also inside the cabin. Most noticeable at night when we're sleeping. But its reassuring to hear those fans running and know that the fridge hasnt broken down.