DIY - Build and install a Bussmann RTMR Fuse/Relay Block

"Ultra Gauge"?

 

If you still have these pieces and there’s enough for two boxes I’ll take them

 

@tacozord
ok gang I'm Shure some one can answer, this question .........im Shure its a dumb ass question, but I got no electrical knowledge,
my bussman build is going to be real tight, Is there a problem with all 10 accessory grounds on one, 5 terminal ground busbar ..
2 accessory grounds on 1 terminal
is this ok to do ?

 

Hopefully some one else will chime in, but a ground is a ground in my mind. The only disadvantage I can see is if something scs up on that ground you will have multiple ungrounded things.

 

"but a ground is a ground in my mind" that's what I was thinking..............

 

You have to do the math. A particular busbar is rated for a certain number of amps. So a ground is not just a ground. When you tie all ten circuits together, the total amount of current going through that busbar and the cable connecting it to the battery will potentially increase. Now this will only happen when all ten circuits are on at the same time. So in theory it might not work, but in practice it's possible. Again...you have to do the math and then make a decision as to what you're comfortable with. For me personally, I would never risk an electrical fire in my vehicle, especially out on a trail, so I'll over-build as a safe practice and never cut corner.

 

So I don't know exactly what was going on with my ABS, VSC, and Ultragauge but everything is good now. Unplugged the Ultagauge, pushed the down page button, and no lights ever since. Hopefully it'll stay that way, but for now it's all good!

 

thanks for getting back to me. I now have another question and I don't mean to be a ass or anything, just trying to learn ........
*by tying both (- busbars) together isn't that essentially making 1 busbar ?, and total current flow through -cable to battery is the same?
* "When you tie all ten circuits together, the total amount of current going through that busbar and the cable connecting it to the battery will potentially increase" wont it be limited to 80 amps ?

once again I'm not trying to be a Dbag
thanks David

 

Yes, tying the busbars together they way they are in the writeup and then connecting the chassis/battery ground to the other end essentially makes a single busbar. If you connect the chassis/battery ground to where the busbars are tied together then each is still a separate busbar. However, the busbars specced in the writeup are 100A busbars, so there's not worries tying them together into one busbar. The Bussmann is only rated at 80A, so you would be exceeding the rated capacity of the Bussmann by 25% before you overloaded the ground busbar(s). Also, 4 AWG wire that is specced in the writeup for the main power and ground feed can handle 80A no problems with the short runs that you'd use to go from the battery to the Bussmann and jumpering the ground busbars together.

 

What he said!

 

thank you Sir I appreciate your help

 

I appreciate your help as well

 

You got it! Now quoting you, "I don't mean to be a ass or anything", a simple answer to your original question would have been "yes". But that's the easy way and not the reason I wrote up the tutorial in the first place. My hope is that you learn something and actually understand what's going on with everything. It looks like you have in this case. It got you thinking about the busbars being tied together, thus becoming one. So with the busbar I chose, it's rated at 100A. And with the RTMR rated at a maximum of 80A, the busbar meets and actually exceeds the rating of the RTMR. So I could tie 100 of them together and they'd all still only allow 100A of current. But then...and here's the gotcha. If you don't size the cable appropriately from the busbars to the battery, then you're screwed and any of the allowable rated current doesn't mean shit anymore. Any circuit will only allow a maximum current that the "weakest link" will allow. Does that make sense? With my design, our ground circuit allows a maximum of 80A because the RTMR is the weakest link.

Alright. Enough tech talk. Back to beer drinking and the beer thread. Cheers!

 

I appreciate the education and thanks for your patients w/me
not looking for the easy way, only have room for 1 ground busbar on my current mount plate , think I'm going to look for different mount plate
for a 2016 auto trd offroad
what I have now just about fits
thanks again

 

That mounting plate looks good, so one busbar will work just fine. Your challenge will be in routing the wiring underneath. Good luck.

 

thank you sir

 

How many accessories are you guys running on the boxes? I have 2 switch panels. Granted one of them has 2 switches for a winch but all together I have about 11 accessories running (C.B., roof bar, bumper bar, rock lights, rear lights, compressor, ditch lights, Sasquatch lights, light for under the hood, lights in the bed and grill light) I also plan on doing an auction battery too so I was thinking I can do another fuse box there if not do them on the same panel.

 

Bussman makes a double sized box for 10 relays/20 fuses. With a second battery it might make sense to locate another box there instead.

 

Also the screws on the busbar are plenty long enough to double up ring connectors so you don't need two buss bars if you only have room for one.

 

This is the best and most detailed DIY ever, THANKS! I am retarded when it comes to wires, took me 3 months and i finally got mine hooked up, i def learned a lot! Amazon was my best friend!