Busbar stacking wires question?

RobOfYork

New Member
If I have a busbar with 6 lugs but have to connect 8 wires to it, can you put 2 wires on a single lug? Of course the busbar would be rated to handle maximum amp load of the system.
 

HRTKD

Boondocker
Yes, that will work. I have have four post bus bars with a couple posts that have two cables into each one.
 

Diysolar123

Solar Addict
make sure to use properly sized COPPER lugs (a curse on whichever marketing fool started the copper clad aluminum trend!!)
 

rmaddy

Solar Enthusiast
When you do put two wires on one stud, put on the wire that needs the most amps first, then the wire needing fewer amps. And this might be overkill but I even put my higher amp-needing wires on the studs closest to the battery and the lower needing wires farther from the battery. The idea is minimizing resistance to the wires needing the most amps.
 

Bob B

Photon Sorcerer
I would double up the ones with the lowest current ... and put the one with the highest current on first as rmaddy said.
 

HRTKD

Boondocker
Thanks everyone. The responses have helped to clear up any confusion I had. I'm learning slowly. :)

Learning slowly is better than learning quickly, which often involves lots of sparks and smoke.
dizzy.gif
 

LB3

Solar Enthusiast
If I have a busbar with 6 lugs but have to connect 8 wires to it, can you put 2 wires on a single lug? Of course the busbar would be rated to handle maximum amp load of the system.
ABYC:
11.14.4.1.10 “No more than four terminals shall be secured to any one terminal stud. If additional connections are necessary, two or more terminal studs shall be connected together by means of jumpers or copper straps.”

11.14.4.1.10.2.1. “...the combined circular millimeters of the conductors does not exceed the circular millimeter capacity of the terminal“
 

Offgrid_UpNorth

New Member
I have two solar charge controllers, so I put the lug on different studs. Something like this:

SCC#1
Battery
Inverter
SCC#2
@HRTKD appreciate showing what you connect where on the Busbar! I have a similar system, with two cc for two different arrays (one is lower voltage/amperage). My question is that when I add an additional set of 6v batteries in series--is it okay to have both negative batteries flow through my battery monitor shunt--one negative going from shunt to busbar... but then my TWO battery positives going to my busbar? Looks uneven--is that okay?

@Hedges mentioned having CC going to same stud:

RED Busbar (4 stud)
SCC#1 & SCC#2
Battery #1
Inverter
Battery #2

BLACK Busbar (4 stud)
SCC#1 & SCC#2
Battery (one negative wire coming from battery monitor shunt)
Inverter
(open stud)

How does that sound?
 

HRTKD

Boondocker
In my case, there is only one positive lead from the battery to the bus bar because there is a switch between the battery and the bus bar.

The optimization of the wiring arrangement is probably only good for .001% better throughput. So don't overthink it too much. Otherwise, your plan looks OK to me. Maybe put SCC#2 on the open stud.
 

Offgrid_UpNorth

New Member
In my case, there is only one positive lead from the battery to the bus bar because there is a switch between the battery and the bus bar.

The optimization of the wiring arrangement is probably only good for .001% better throughput. So don't overthink it too much. Otherwise, your plan looks OK to me. Maybe put SCC#2 on the open stud.
Thanks @Hedges appreciate reigning in my analysis paralysis :) I have a switch i planned to install between my two 6v series positive and busbar. Not sure how I’ll tie in another series of batteries to the shutoff and busbar down the road, but will post that question later after I research more!
 
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