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Blown fuse

Posted: 24 Jul 2006, 16:18
by Jonni
I tried out my fridge on the 12v the other day and it blew the fuse (10a). Is there something I should know?

Posted: 24 Jul 2006, 17:33
by dbroada
at what point did it blow? As you switched on or when you drove home after?

basically the fridge is around 100Watts, so on 12v will draw 100Watts/12 volts = 8Amps. So a 10 Amp fuse should be OK but it is a bit marginal. If your battery is a bit flat - say 10 volts then the sums become 100/10 = 10.

Alternatively, if it blew when you started the van it's because the battery was discharged and your alternator AND other battery tried to recharge it too quickly.

And finally, if you consider the 10 Amp fridge load is about the same as a heated rear window and would you leave one of them on without the engine running? I hope not. Fridges EAT 12v batteries which is why you should only run them off the alternator.

Posted: 24 Jul 2006, 21:04
by Jonni
Thanks for the reply Dave. I don't actually know when it blew to be honest.

Posted: 24 Jul 2006, 21:36
by dbroada
I would make sure the LB is charged using a mains charger THEN replace the fuse. (I am assuming you have a 3 way fridge). The problem is trying to test these fridges. They can take hours to get cool (especially on 12v) so you can't really test them from a battery.