Ground wire question?

[RioDeColumbia]

So I am trying to wire an auxiliary fuse box, and currently I am wiring up relays. The relays max out at 30 amps. The way I have wired them so far is I took on ground wire and piggy backed them into each of the 7 relays. So basically I am grounding all the relays off of 1 wire. My question is what would be the right gauge wire to do this with? Currently I am doing it with about 18-20 gauge wire, I don't know exact size but it's in that range I think.

 

[Jbat]

7 relays at 30 amps each? I'd use a bigger ground. Or run a couple separate ones

 

[RioDeColumbia]

7 relays at 30 amps each? I'd use a bigger ground. Or run a couple separate ones

How big of a ground wire do you think I should use then if I were to just use one wire. Do you think like 14 awg would work? Some people have been telling me my current set up would barely work, but it is better to use bigger wire to be on the safe side.

 

[Jbat]

I'd say you'd probably be ok with 12-14

 

[mudchet]

Assuming the round trip length of wiring from the fuse block to relays is 3' or less then 10 gauge is the minimum you can safely use. You are asking that wire to potentially carry over 200 amps of current. Thats quite a bit.
http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm

 

[RioDeColumbia]

Assuming the round trip length of wiring from the fuse block to relays is 3' or less then 10 gauge is the minimum you can safely use. You are asking that wire to potentially carry over 200 amps of current. Thats quite a bit.
http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm

Alright, then I will get bigger wire then, thanks for the help everyone!

 

[Jbat]

Assuming the round trip length of wiring from the fuse block to relays is 3' or less then 10 gauge is the minimum you can safely use. You are asking that wire to potentially carry over 200 amps of current. Thats quite a bit.
http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm

And there you have it. Nice chart, totally stealing it.

A question I have for OP is what's the chance that all the relays will be on at the same time?

 

[RioDeColumbia]

And there you have it. Nice chart, totally stealing it.

A question I have for OP is what's the chance that all the relays will be on at the same time?

I probably won't have them all on at one time most likely. I probably will only have like 4 on at one time. And yes, that chart is very handy!