Fuse for fridge

Submitted: Monday, Aug 26, 2002 at 00:00

ThreadID: 1821 Views:1245 Replies:8 FollowUps:2

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Smutty

What size fuse should I use at the battery if i'm running 6mm wire to the back of my truck for running a fridge that draws 3 amps and also an extra socket for a fluro. Cheers

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Reply By: Member - Nigel - Monday, Aug 26, 2002 at 00:00

Monday, Aug 26, 2002 at 00:00

a 5 amp fuse should do it, and if that blew then maybe a 7.5 amp. The fluoro should only draw around an amp, and there shouldn't be much loss in the cable.

AnswerID: 6047

Reply By: Sparky - Monday, Aug 26, 2002 at 00:00

Monday, Aug 26, 2002 at 00:00

Hope you don't get stuck with any sort of electrical problem in the bush, Smutty!!! If your fridge draws 3 amps and a fluoro quite a lot less you only have to add the two together and maybe allow a bit more if you wish fior a safety margin and you get a 10 amp fuse to cover it easily. Try less if you wish but there's no real point as you're looking at guarding against a short circuit and thereby a fire and 10 amps will certainly do it for you! Also a tip - trial and error is an excellent way of solving a problem - try a 4amp fuse. If it blows try larger etc.

AnswerID: 6050

Follow Up By: Smutty - Tuesday, Aug 27, 2002 at 00:00

Tuesday, Aug 27, 2002 at 00:00

Sounds like i'm a bit lacking in electrical knoledge hey, but i'm a licienced electrician and work in the electronics field. The reason i asked the question is it seems that autoelectricians and 4WD shops around my area are full of bleep. I just had to make sure i wasn't going crazy or missing something really obvious. Doing the resistance versus voltage drop figures i can just justify 6mm cable altough 4mm would be ample. The 4WD shop said just throw in 6mm cable and a 30 amp fuse(amazing) and the auto electrician(who had the best price for cable) said a 20 amp fuse would be good. The totally amazing thing i came across was the fuse holders they were both using. They were both fly wire fuse holders with approx 3mm cable leads. Talk about inducing your own voltage drop!!!!! I feel sorry for people who have limited mechanical knowledge and visit shops that are supplying sub standard engineering/ workmanship. Cheers Smithy

PS At least people on this forum have a bit of common dog bleep.

FollowupID: 2656

Follow Up By: Sparky - Thursday, Aug 29, 2002 at 00:00

Thursday, Aug 29, 2002 at 00:00

Smutty, you are an electrician? I am amazed.

FollowupID: 2690

Reply By: Rob - Monday, Aug 26, 2002 at 00:00

Monday, Aug 26, 2002 at 00:00

http://www.aroundoz.8m.com/diy_vehicle_fridge_wiring.htm

AnswerID: 6052

Reply By: Member - Nigel - Monday, Aug 26, 2002 at 00:00

Monday, Aug 26, 2002 at 00:00

Something I forgot earlier, the startup current of the fridge compressor may be more than the rated amps of the fridge, so a 10 amp fuse would probably be a better option than a 5 amp.

AnswerID: 6055

Reply By: Mal58 - Tuesday, Aug 27, 2002 at 00:00

Tuesday, Aug 27, 2002 at 00:00

Smutty,
With the instructions that came with my Fridge, it suggested that you use a "self resetting" circuit breaker rated at 15 or 20 A. This I did, and have had no problems.
Rgds,
Mal58

AnswerID: 6070

Reply By: Blackie - Tuesday, Aug 27, 2002 at 00:00

Tuesday, Aug 27, 2002 at 00:00

I hate it when I can't work out what the bleeps are.

AnswerID: 6073

Reply By: John - Tuesday, Aug 27, 2002 at 00:00

Tuesday, Aug 27, 2002 at 00:00

G'day smutty,
I recon I would run A Higher Rating fuse, and probly go with the 20 or 25 amp.
The reason I say this is, What are you protecting anyway....I asume its the supply line to to rear of the vehicle, incase of shorts etc etc, A 25 amp fuse with blow very rapidly if that occurs.
Put the fuse right at the battery so if you get a rub through on the cable you are still protected (amazing how many people put their fuses at the rear of the vehicle).
Anything you plug in should have its own protective fuse anyway.
To small a fuse in the supply line causes all sorts of nusance tripping of the fuse, such as varing loads presented by the fidge, surge currents etc etc.
And as sujested above a thermal circuit breaker (resetable) on the supply line fitted right at the supply (battery) is by far the best option.
Anyway good luck,...John

AnswerID: 6075