Relays and Fuses
#21
Originally Posted by deathrunner
Ok 4crawler got me thinking.
With respect to relayed devices. Say my 55watt lights. From the battery I have a fuse, then the relay. They on the other end of the relay is the switch. Do I need a nother fuse before the switch? That would make sense to me.
Since I plan to have 3 relayed devices and also thier 3 switches (front lights, rear lights, air compressor), coudl I feed all three of the switches from one fuse in my fuse block? Seems like thye would all have very little draw and I could combine them on 1 fuse.
With respect to relayed devices. Say my 55watt lights. From the battery I have a fuse, then the relay. They on the other end of the relay is the switch. Do I need a nother fuse before the switch? That would make sense to me.
Since I plan to have 3 relayed devices and also thier 3 switches (front lights, rear lights, air compressor), coudl I feed all three of the switches from one fuse in my fuse block? Seems like thye would all have very little draw and I could combine them on 1 fuse.
ok but heres the problem with that. You turn on the air compressor and the motor is stuck, maybe the windings in the compressor can only handle 5 amps. Well you have a 10 amp fuse in line, so the weakest link is going to be the motor windings burning up.
So basically you can use the same wire (you should take the sub straight to the battery) but you should have each device fused with the correct size fuse.
You can put the fuse anywhere before the actual load, before or after the switch on the hot side. The best place is always as close to the power supply as possible though. I like that in case a wire breaks and shorts to the frame, then the fuse will blow before burning up the wire or whatever.
As far as a relay. I only use them when I want something else to do the switching IE. brake lights bringing on aux lights. To turn on fog lights I would just use a fuse, wire, switch and fog lights.
#22
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I guess the nice thing about putting a realy for the lights is I don't have a ton of flow coming into the cab where the switch is. Does that make sense?
Maybe I can put a different fuse on each switch but still feed from one wire.
Maybe I can put a different fuse on each switch but still feed from one wire.
#23
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Originally Posted by deathrunner
I guess the nice thing about putting a realy for the lights is I don't have a ton of flow coming into the cab where the switch is. Does that make sense?
Maybe I can put a different fuse on each switch but still feed from one wire.
Maybe I can put a different fuse on each switch but still feed from one wire.
But, for the switches (and thus relays), it is ok to use a single fuse to feed them. Its the +12V prong on the relay that you want a seperate fuse for each circuit and relay.
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09-28-2015 10:30 PM