Fridge Wiring 'Sort Out'

[Alan de Enfield]

After a couple of months away from the boat due to family commitments in Asia I have finally started again of the wiring 'spaghetti' on the boat.

 

All of the 12v wiring was wired with 'Black & Decker' orange cable of 0.5mm^2, or 1mm², and all of the 220v side with 2.5mm²Arctic three-core.

No identification just loads of orange cables running alongside each other from the fuse panels.

 

Now getting towards the end and started to tackle the 12v Waeco fridge :

 

The fridge has been a bit of a problem for some time, in that whilst cruising it is fine with ice in the ice box, but when moored up the ice melts and the fridge is running almost continuously.

 

I decided that the obvious cause was low voltage at the fridge, so out came the meter and sure enough it was 11.5v at the fridge when it was running and 12.8v when it had 'clicked off'

 

The cable was (at most) 1mm² and the run was about 2 metres each way from the switch panel / busbar.

Reading the Waeco manual it should be 4mm² over that length.

 

I don't have any 4mm or above in the spares box so it will be a trip to find an electrical wholesaler who will sell a short length.

 

I'll report back if it solves the problem

Edited September 15, 2016 by Alan de Enfield

[Opener]

We had a similar issue, although the fridge would just 'flash' it's warning light and cycle on and off continually. John the 'lecky measured low voltage at the fridge, banged in some decent gauge cable (sorry - not sure of sizes before and after) and we have had no problems since.

[Horace42]

If you have some spare cable connect it in parallel with the existing cable. No need to run the cable the same route. Just lay it on the floor and connect each end. This will tell you if you are on the right track.

If you have some 2.5mm spare cable you can run that in parallel (= 5 mm) to replace the existing wire

[Tony Brooks]

I think its 1 sq mm CCSA for each metre between battery and fridge but use the same size cable for the return. I think 2 sq mm CCSA would suffice IF a suitably large cable feeds the switch panel and bus bar. However with fridges I would always go for larger than smaller.

[Alan de Enfield]

 

I think its 1 sq mm CCSA for each metre between battery and fridge but use the same size cable for the return. I think 2 sq mm CCSA would suffice IF a suitably large cable feeds the switch panel and bus bar. However with fridges I would always go for larger than smaller.

 

 

The cables from the batteries to the busbars are both 'huge' (about 1/2" diameter of copper + insulation - they are the same size (maybe even bigger) as the battery to starter motor cables.

[Catnip King]

I am interested in this so following the topic. I've got a super expensive fridge but got same problem as you. The cables running through are thin orange so looks like mine can be fixed by doing this too

[ditchcrawler]

After a couple of months away from the boat due to family commitments in Asia I have finally started again of the wiring 'spaghetti' on the boat.

 

All of the 12v wiring was wired with 'Black & Decker' orange cable of 0.5mm^2, or 1mm², and all of the 220v side with 2.5mm²Arctic three-core.

No identification just loads of orange cables running alongside each other from the fuse panels.

 

Now getting towards the end and started to tackle the 12v Waeco fridge :

 

The fridge has been a bit of a problem for some time, in that whilst cruising it is fine with ice in the ice box, but when moored up the ice melts and the fridge is running almost continuously.

 

I decided that the obvious cause was low voltage at the fridge, so out came the meter and sure enough it was 11.5v at the fridge when it was running and 12.8v when it had 'clicked off'

 

The cable was (at most) 1mm² and the run was about 2 metres each way from the switch panel / busbar.

Reading the Waeco manual it should be 4mm² over that length.

 

I don't have any 4mm or above in the spares box so it will be a trip to find an electrical wholesaler who will sell a short length.

 

I'll report back if it solves the problem

I have bought short lengths on eBay, handy if you only need a few meters

[Stormbringer]

I ran 2 pairs of 6mm sq to my shoreline 12v fridge, 10m from the supply and it cured all my voltage drop problems!

Been great since ....

[Bee]

Not quite the same thing but heavier cable will often sort out badly installed eberspachers and things (its still an Eber though so not quite a cure all)

[Alan de Enfield]

I have bought short lengths on eBay, handy if you only need a few meters

 

I had a look at Ebay but flexible single core seemed to run out about about £2,99/metre.

 

Called in at my local "Truck Component Motor factors" and bought a 30 metre drum of 4.5mm² for £17.80

Will have plenty left for any other 'tidying up' jobs.

 

(In the past they made me up a 1metre long battery cable with two ring terminals hydraulically crimped on and heat shrink sleeved for £6.87 + VAT)

 

They may be of interest to others :

 

"Motor Parts Direct" About 90 branches - A nationwide company

 

https://www.mpdonline.co.uk/stores

 

I get my engine filters from them as well (a fraction of the price of the OEMs)

[ditchcrawler]

I had a look at Ebay but flexible single core seemed to run out about about £2,99/metre.

 

Called in at my local "Truck Component Motor factors" and bought a 30 metre drum of 4.5mm² for £17.80

Will have plenty left for any other 'tidying up' jobs.

 

(In the past they made me up a 1metre long battery cable with two ring terminals hydraulically crimped on and heat shrink sleeved for £6.87 + VAT)

 

They may be of interest to others :

 

"Motor Parts Direct" About 90 branches - A nationwide company

 

https://www.mpdonline.co.uk/stores

 

I get my engine filters from them as well (a fraction of the price of the OEMs)

I only suggests ted it as you said you were going to an electrical wholesaler then you would need 2 reels

[Chalky]

When I fitted the boat out I ran a pair of 25mm cables from the domestic fuse box (via a 45A breaker) to a fuse box in the middle of the boat. The plan was to run a 12V fridge from there. I ended up fitting a mains fridge so they've never been used for a fridge however the cable has been useful for adding a number of circuits that have been added since the fit out (reading lights, sockets etc).

If its only 2 * 2m lengths then fit the biggest you can or fit a local fuse box and distribute from there.

[WotEver]

I only suggests ted it as you said you were going to an electrical wholesaler then you would need 2 reels

 

Or one reel and some red insulting tape

[Richard10002]

When I fitted the boat out I ran a pair of 25mm cables from the domestic fuse box (via a 45A breaker) to a fuse box in the middle of the boat. The plan was to run a 12V fridge from there. I ended up fitting a mains fridge so they've never been used for a fridge however the cable has been useful for adding a number of circuits that have been added since the fit out (reading lights, sockets etc).

If its only 2 * 2m lengths then fit the biggest you can or fit a local fuse box and distribute from there.

 

My fridge works fine, but I get some voltage drop between the main switch board and sockets at the front of the boat.

 

I'm thinking of running a pair of thicker wires from the main switchboard to a second board in the saloon, then feeding from that.. I was thinking 25mm2 as more than enough.

 

The only difficulty is running it hidden. I'd guess the existing wires were fitted as the boat was being built, so they run along the ceiling behind the panels... Anyway.. I'll have to find a way over the winter some time.

[cuthound]

Or one reel and some red insulting tape

Or red & black heat shrink.

[WotEver]

Or red & black heat shrink.

Well now you're going all high tech

[ditchcrawler]

 

Or one reel and some red insulting tape

A bit like old Fords, whatever colour you like so long as its black.

[WotEver]

A bit like old Fords, whatever colour you like so long as its black.

Which I always believed was true until last week when I learned that the only colour that you couldn't buy a Model T in was black. From its introduction in 1908 up until 1913 you could have one in blue, gray, green, or red, but not black.

 

It's true from 1914 onwards though

 

Tony

[Paul C]

You could do what Peugeot do.....just use any colour to hand, but print tiny numbers along the wire which are bound to rub off or be completely illegible when you come to wire a towbar or something......

[Neil Smith]

My 12v fridge freezer is 2 metres away from the fuse board and is wired in 2mm cable with no problems when off grid.

 

Neil

[WotEver]

My 12v fridge freezer is 2 metres away from the fuse board and is wired in 2mm cable with no problems when off grid.

 

Neil

Which proves absolutely nothing other than you are lucky.

[Tony Brooks]

And just happens to comply with the usually recommended 1 q mm CCSA per meter between battery and fridge with the almost certainly large CCSA cable to and from the fuse board being more than adequate to prevent volt drop on the fridge starting.

 

The message from thins thread must be "use the recommended size of cable or larger for electric compressor fridges".

[WotEver]

 

And just happens to comply with the usually recommended 1 q mm CCSA per meter between battery and fridge...

 

I believe that's the 'there and back' distance, so in this case should be 4mm².

 

But with the short-ish run plus a good thick cable to the fuse board he's got away with it.

 

Tony

[Tony Brooks]

 

I believe that's the 'there and back' distance, so in this case should be 4mm².

 

But with the short-ish run plus a good thick cable to the fuse board he's got away with it.

 

Tony

 

The Danfoss collection of Data sheets for the BD35 series of 12V compressors gives a table that on a glance seems to confirm your view but the maximum cable length heading has a small star by it. Below the tables it says "* Length between battery and electronic unit".

 

My old Shoreline instructions said 1 sq mm CCSA for each metre between the battery and fridge and use the same size of the negative. The table in my present Waco instructions confirms this.

 

However as I said the thicker the better so your interpretation will never cause people grief - unlike a certain professional marine harness supplier but I can not go into that on a public forum because they were still of the view that their calculations trumped Danfoss and colluded with the fridge an freezer makers to alter the fridge settings rather that supply and fit the recommended cable..

[Machpoint005]

A bit like old Fords, whatever colour you like so long as it's black rust.