12v cable problem

[Oliver]

With age, our 12v Shoreline fridge has developed a problem giving the '1 light' error message (Battery voltage below the cut out setting) - quite often. This didn't use to happen, but the fridge (and our batteries) are now 7 years old. Having checked the wiring, the builder used 6mm cable for a 35 foot run from the batteries but the fridge manufacturer says 10mm should have been used.

 

Have just spent a very frustrating day trying to run 10mm cable from the batteries to the fridge but can't get the wire behind the panelling in the galley. Tried attaching the 10mm wire to the 6 mm and pulling it up but we can't get past a narrowing which we think is either a cable tie or a baton or something and which we can't get to (or see). Have looked at different routes but we simply can't get the 10mm wire to the fridge without wrecking a large area of panelling or other areas.

 

My question is this.

 

Would running the 10mm cable from the batteries to about 3 foot from the fridge and then using a jointing block to connect to the 6mm give less voltage drop than when the 6mm cable was in place for the whole 35 foot?

 

Thanks

(Builder now defunct so can't go back to him.)

[by'eck]

Yes although not ideal.

[bowten]

With age, our 12v Shoreline fridge has developed a problem giving the '1 light' error message (Battery voltage below the cut out setting) - quite often. This didn't use to happen, but the fridge (and our batteries) are now 7 years old. Having checked the wiring, the builder used 6mm cable for a 35 foot run from the batteries but the fridge manufacturer says 10mm should have been used.

 

Have just spent a very frustrating day trying to run 10mm cable from the batteries to the fridge but can't get the wire behind the panelling in the galley. Tried attaching the 10mm wire to the 6 mm and pulling it up but we can't get past a narrowing which we think is either a cable tie or a baton or something and which we can't get to (or see). Have looked at different routes but we simply can't get the 10mm wire to the fridge without wrecking a large area of panelling or other areas.

 

My question is this.

 

Would running the 10mm cable from the batteries to about 3 foot from the fridge and then using a jointing block to connect to the 6mm give less voltage drop than when the 6mm cable was in place for the whole 35 foot?

 

Thanks

(Builder now defunct so can't go back to him.)

It will help but would be better of course if yer could get that damned last few feet.How about using 12mm cable and connecting to the 6mm.

Edited April 21, 2012 by bowten

[Ex- Member]

You probably have, but did you try pulling the cable through Both ways. Just a thought!

[bowten]

You probably have, but did you try pulling the cable through Both ways. Just a thought!

OOOH I never thought o that,cool one dude.

[Oliver]

Julynian - yes tried pulling both ways.

 

Bowten - we've already bought 80 foot of 10mm cable (40 ft each of red & black)

 

Will sleep on it and see if inspiration strikes and we can get that last 3 foot.

 

Thanks

[Ex- Member]

Julynian - yes tried pulling both ways.

 

Bowten - we've already bought 80 foot of 10mm cable (40 ft each of red & black)

 

Will sleep on it and see if inspiration strikes and we can get that last 3 foot.

 

Thanks

 

I'm not sure how much panelling you can get to and how much you have to traverse, but in the past I've used 15mm plastic plumbing pipe and drain rod. But the best is the carbon fibre telescopic poles, I do have quite a bit of space behind my lower panelling though and got well over half way up the boat with one of these.

 

 

[bowten]

Julynian - yes tried pulling both ways.

 

Bowten - we've already bought 80 foot of 10mm cable (40 ft each of red & black)

 

Will sleep on it and see if inspiration strikes and we can get that last 3 foot.

 

Thanks

Yep cheap it aint.

[The Bagdad Boatman (waits)]

Can you feed multiple i.e. 3x6mm cable for the last yard?

[Arthur Brown]

Actually as you say that the whole system is seven years old, I'd expect the fridge to be ageing due to moving parts and the batteries to be ageing due to natural process but not the cable to be degrading with age, though the connections could be degrading and needing cleaning. Actually I'd be looking at the charging and battery systems.

[DeanS]

Before running the 10mm wire, have you tried connecting it by running the cable down the passage etc temporarily to see if the problem with the fridge IS actually the cable. If you still have the light going on, it could be something else, like a bad battery connector. I would do that before hassling too much getting it through the cable ducting?

[Brummegem]

If the problem was a voltage drop,this would be ok running 6mm cable for the last few feet,but would say that the problem exists in the batterys or the fridge,as the batteries and the fridge have worked well for 7 years with the existing cable.I would run a 120strand by.3mm cable for this run meaning that there are 120 thin copper strands within the cable each been .3mm thick.Have you been advised that the original cable is 6mm or it could be Thin Wall(TW)cable which would look a lot thinner than the new cable you have purchased but contains the same amount of copper.

[cheshire~rose]

On our boat we tend to use the fridge operating light as a visible warning of when the battery level is getting low. It flashes a green light on and off when there is a low battery level and when all the lights are off in the cabin it is very noticeable that something is flashing. We used to see it regularly if one of us got up to use the loo in the night and we knew that as soon as it was a reasonable time to do so the next morning we would need to start the engine and get some life into the batteries.

 

That was before we replaced the batteries! We rarely see the light now and as others have said if the fridge has been running perfectly well with the existing cable up until now I would suspect at the age they are it is time to bite the bullet and replace the batteries.

[bottle]

As others have said, if it has been OK for seven years. What has changed?

 

Answer the batteries are seven years old and are dying/dead.

 

Yes change the cable but as I and others think the problem is in the charging/battery area.

 

The batteries have lasted very well, so the charging regime must be good.

 

So that just leaves the batteries.

[rgreg]

If you phone Shoreline they can send you a small wire which attaches to the connectors at the rear of the fridge and reduces the voltage cut out level. It used to cost less than £10.

[NMEA]

Cable pulling using the old cable as a mouse often results in a foul, usually due to the joint between the two cables, if you join with adhesive lined heat shrink there will be no areas to foul and you get a nice smooth transition between the two, a bit of WD on the cable helps too. I use this method for running radar, VHF and nav light cables up very tall yacht masts as well as interior cabling and it has never failed me (yet). Also if you use really good quality thinwall cable it may well have the same or very close O/D to what you currently have.

Edited April 22, 2012 by NMEA