Thread: Fuse or Circuit Breaker

Originally Posted by drivesafe

He has no idea what he is talking about.

How can you say that, he’s Ronny Dahl - he’s an influencer.

Originally Posted by AK83

For d2dave, have you already installed an fuse/breaker to the aux battery? Is the question just related to how to fuse aux to the van?

Yep Aux battery was installed over 10 years with a 50 amp breaker at both ends.

This thread is about protecting my cable from aux battery to campers house batteries, via Anderson plug on rear bumper.

Isn’t that what you catch when you drive with the window open ?

Dave,
Ho much current do envisage the Tvan batteries drawing?

What cable is running from the cranking battery to the auxiliary battery?

I can't see the point of a 100 amp braker/fuse between the auxiliary batt and the Anderson plug when there is a 50 amp braker at the main batt, as all your current needs to pass through that 50 amp braker.

Can you connect you new cable to the non battery side of the rear circuit braker, rather than have a second one?

Tony

For my minor contribution - fuses are cheaper and probably more reliable - but you need to have replacements when you need them. And in a few years, these may not be as easy to find, especially in Woop-Woop!

Circuit breakers are much more convenient in use, but more expensive, and if it does need replacement, an exact replacement is not going to be readily available.

I do both, a resettable circuit breaker or self resetting if its a critical requirement thing with a bigger fuse.

so if you want a 100A load youd fit a 100A circuit breaker with a 120A fusible link between the breaker and the battery.

The logic.. if thecircuit breaks in the middle of no where shorting out, it trips the breaker. you find the damage, fix it and reset the breaker, and you can do this dozens of times if you need to (say you have an intermittant cable nick you cant find) if the breaker spot welds itself and you get the short, the fuse goes.

Remember if your doing it for a battery to battery connection you need circuit breakers and fuses at each end of the cable.

The suggestion of the 80 amp fuse, is to future-proof the setup.

The circuit breakers may last for ever, or need replacing at some time.

50 amp auto resetting circuit breakers can tolerate sporadic high current event that may trip them, but then they just cool down, reset and everything gets back to working and you will never be aware the system has tripped.

But a 50 amp fuse or manual resetting circuit breaker in the same type of event, will leave the setup open circuit until you discover the system has tripped.

So you need to replace an auto resetting circuit breaker with a higher current capacity fuse or manual resetting circuit breaker to reduce the chances of such event causing issues and with 6B&S cable, 80 amps is the highest safe current rating you can use.

Originally Posted by TonyC

Dave,
Ho much current do envisage the Tvan batteries drawing?

What cable is running from the cranking battery to the auxiliary battery?

I can't see the point of a 100 amp braker/fuse between the auxiliary batt and the Anderson plug when there is a 50 amp braker at the main batt, as all your current needs to pass through that 50 amp braker.

Can you connect you new cable to the non battery side of the rear circuit braker, rather than have a second one?

Tony

A good point Tony. However, as I am running a fuse I am going for a fuse with a higher amps than the breakers. This way the breakers should protect the fuse.

The fuse will still protect the cable from aux battery to the Anderson plug and through to the house batteries.

And yes I could probably connect the cable between existing circuit breakers, but with the way it is set up this would involve a longer run of this very heavy cable and be more labor intensive.

And to answer your first question, batter to battery is 6 B&S, the same as I am running to my Anderson plug.