Wire Gauge, Fuses and Relays

So I've done my fair share of 12V electrical wiring in my Tacoma (Bussmann relay/fuse panel, lights, radios, etc) but I need some advice for this Rigid E-Series 20" light bar that I'm installing on my Tundra.
https://www.rigidindustries.com/e-series-pro-20-spot-flood-combo-black-120313.html



The specs say 214 watts, Amp Draw 15.



I purchased this Light bar without the Rigid Harness so I'm building my own. I'm using the same Deutsch DTP2 connectors so I can plug into the light bar, but I'm trying to figure out what wire GA to use and what fuse. I have a 40V relay that I will mount in the engine bay, wired to a switch in the cab.

My math says 214W/13.8V = 15.5 Amps, specs say 15A draw. Guessing the circuit will only be 10ft or so, so only a 3% voltage drop, plus the 80% rule. 15.5 calculated x 1.2 = 18.6Amps.

I've seen a bunch of different charts, some calling for 10ga wire, 12ga and 14ga. this one from Blue Sea says 12ga


this one says 10AWG


Looking for someone here to double check my math.

What wire gauge should I use and what size fuse?

 

I would think that the 12 gauge and 15 amp is fine. @RainMan_PNW is our go to electrical guy.

 

Thanks for tagging the guru! I was leaning towards 12ga/15A, 10ga seems like too much. Id like to use 14ga but I think that might be cutting it close.

 

I have a 30" single row Rigid lightbar I'm going to install soon and I plan to just match the wiring lead that was coming off the back of the bar itself — 12ga

 

http://circuitwizard.bluesea.com/

 

For DC stuff, this is what I use (same that Dave just posted) to check things.

I'm an amateur at best, and more adept at chasing down wire diagrams and figuring out switches and relays than the rest of it, but thank you.

Now, I see you stating 13.8V, but that is "optimum voltage" when with the alternator providing power. You should figure your math at battery voltage (12V) which puts that amp load closer to 18 (so either the stated wattage is wrong or the stated amp draw is wrong). Either way, plugging in the info in the above calculator for a "critical voltage drop" you come up with #12 (same as the blue sea chart you posted). And honestly, unless you have your relay in the cab itself, your wire length should really be under 6ft most likely and you could get away with #14.

 

Exactly what I was looking for, thank you!

 

Solid DTP pins/sockets are a size 12 and accept 12 or 14AWG. Run 12AWG for a bit of buffer if you ever overload and blow a fuse.

 

Appreciate the advice, I think I will run 12ga just for a bit of a buffer. I don't want to put the end of the connector off the light bar because its a $800 light bar lol. I basically got it for free, I bought a 2014 and up Rigid Tundra Grill insert for $150 and it had the 20" E series and 2 Rigid Dully Pods, took the lights out and sold the insert for $150!

 

I kinda wish I had the single row 30" rigid light bar because this 20" double row is going to be tricky to mount on my 2nd gen. They dont really make brackets and I want it to be flush somewhere on the front bumper. Its just a hair too tall to fit right above the license plate, might be able to sneak it behind the grill.
got any ideas?

 

Since you have the mesh grill you could probably put it behind there and still get pretty good light output. Or maybe get one of those "hidden lower lightbar brackets" that keep it behind the plastic and then make a little spacer on each side to fit the 20"?