charts

crazyboy · Post by **crazyboy** » Wed Dec 01, 2004 11:44 am

does anyone hae charts with a list of what ga. wire & what size fuse to use for different things? thanks

Post by Pj » Wed Dec 01, 2004 12:13 pm

Go to page 7

http://install.whelen.com/137/13709.pdf

crazyboy · Post by **crazyboy** » Wed Dec 01, 2004 12:23 pm

ok thanks. how do i find out what size fuse to use? thanks.

KG6EAQ · Post by **KG6EAQ** » Wed Dec 01, 2004 1:17 pm

The size of the fuse depends on the requirements of what you'r fusing. The manual should tell you what it draws and then you can judge from there.

crazyboy · Post by **crazyboy** » Wed Dec 01, 2004 2:17 pm

yea but how do i judge? should i just go to the next size fuse above what it draws? so say that something drew 4 amps would i go with a 5 amp fuse?

Post by **alex** » Wed Dec 01, 2004 7:31 pm

That's probably not a horrible idea.

-Alex

Thu Dec 02, 2004 3:16 am

That's pretty much how it works. You try to find the next size closest (above) to the rated maximum draw of the device you are fusing. You don't want to go to the same size as the max draw as it is almost guaranteed to blow the fuse.

Sam · Post by **Sam** » Thu Dec 02, 2004 7:30 am

Isn't the fuse supposed to be protecting the *wiring*? If your feed is sized to handle, say, 80 amps, you don't want a short or too high of a load to draw more than that and overheat the wire, so you use an 80-amp fuse close to the power source, right?

I seem to recall a thread about idiots idiots idiots

...

Tech225 · Post by **Tech225** » Thu Dec 02, 2004 5:18 pm

eng5 wrote:Isn't the fuse supposed to be protecting the *wiring*? If your feed is sized to handle, say, 80 amps, you don't want a short or too high of a load to draw more than that and overheat the wire, so you use an 80-amp fuse close to the power source, right?

I seem to recall a thread about idiots idiots idiots ...

You're right, partially. You need to protect the main wire run at the power source. When you start your distribution network, you protect the individual wires with their own fuses, rated for whatever accessory they feed. I like to have another fuse directly at the accessory, most already have them built right in. Some may deem all this to be overkill, but I'm happy with it.

nmfire10 · Post by **nmfire10** » Thu Dec 02, 2004 8:07 pm

eng5 wrote:Isn't the fuse supposed to be protecting the *wiring*? If your feed is sized to handle, say, 80 amps, you don't want a short or too high of a load to draw more than that and overheat the wire, so you use an 80-amp fuse close to the power source, right?

I seem to recall a thread about idiots idiots idiots ...

Yes and no. If you have wire rated for 80 amps but the device it is powering only draws 5 amps, you would not fuse it for 80 amps. You would fuse it 7 amps. If someing in the device shorts, it will do a lot of damage before it starts drawing 80 amps to blow the fuse... if it even does. So your wiring will be fine but the device itself is still going to be smoking. So, fuse it for the device your running and not to exceed the wiring capability.

And yes, who can forget the "idiots, idiots, idiots" incident. However, that is the result of some [language] who used NO FUSE being fed by a 400 amp master and resulting in the poor sucker working on it later (me) burning my hands and filling the truck with smoke.

thebigphish · Post by **thebigphish** » Thu Dec 02, 2004 11:28 pm

didn't you post a pic of that mess after?