Fuse or Circuit breaker on diy canister light?

[pcscuba]

I'm almost done building my light. I've gotten down to the wiring and I was wandering what everyone was using. I could use a circuit breaker but it is difficult to find one that I can bolt down. Then again I could use a fuse. (Same problem) What do you guys think?

[canuckdiver]

my personal preference would be a circut breaker. That way you don't have to dissassemble any more of the wiring/battery than is absolutely neccessary. You can buy breakers that are solder-lead equipped, about the same size as a AAA battery ;)

[nickjb]

If you can get a circuit breaker then that will be best. A thermal fuse would be nice too. These are either self resetting or one shot (hard to solder, but cheap).

The simplest way to add a basic fuse is to use a car one. These fit straight onto a pair or 1/4" spade connectors (and you usually have a spare to hand)

[DNAXdiver]

cave and tech divers have alwasy regarded fueses and circuit breakers as being in the same category as burst disks on tanks additional failure points more likely to cause problems than avert them thats why you wont see them on any serious caving light

circuit breakers espec they are delicate and fussy items not really suited for damp envirionments unless you get milspec

they are the sort of convolution that tends to show up on lights made/sold by people who have very little experience using them might want to ask the guyes recommending them how many years theyve been cave dving

just mark your wires carefully be careful when you hook up your charger dont leave any bare wires to short and replace your cord before it is totally knackered and youll never need a fuse


pcscuba once bubbled...
I'm almost done building my light. I've gotten down to the wiring and I was wandering what everyone was using. I could use a circuit breaker but it is difficult to find one that I can bolt down. Then again I could use a fuse. (Same problem) What do you guys think?

[nickjb]

DNAXdiver once bubbled...
cave and tech divers have alwasy regarded fueses and circuit breakers as being in the same category as burst disks on tanks ....



I tend to agree. But... while the wiring in a DIY torch isn't exactly rocket science there is a lot that could go wrong. NiCds, for example, have a very low internal resistance and can give out a huge amount of energy if shorted.

We had to evacuate our building when one of our contractors overcharged a battery pack we were experimenting with. It was very messy.

I'd suggest putting some protection in it until you are completely happy with the way it works

[mddolson]

I placed a standard automotive 6 amp fuse in my 12 volt cannister light.

It handles the 50 amp inrush current of my 50 watt MR16 halogen lamp just fine.

I also suggest you use a 1 - 1.5 HP dc rated switch for the same reason.

My fisrt switch was only 1/2 HP rating and it welded itself ON.

Mike D