Trimetric shunt/wire size question
I’m planning the install of a Trimetric battery monitor and I have a question about mounting/wiring the shunt. After studying my layout, I feel the simplest way to mount the shunt is to make a brac...
Forum Discussion
BFL13 – I’ve considered adding a bit of copper to the far side of the shunt for my portable charger clamps. But, as you said, the shunt bolts are too short to take many lugs.
I measure the bolts at 5/8-inch and the threaded holes in the shunt at 1/2-inch. Factor in the lockwasher, the flatwasher, the big cable lug, we’re down to less than 3/8-inch of threads gripping. Add in a flattened copper pipe for clamping the charger and the grip gets down to about 1/4-inch. That makes me a bit nervous.
I’ve thought about substituting a longer bolt, but I don’t know what throwing a different metal into the mix will do the the electrical properties of the shunt, so I decided to play it safe and stick with the original bolt.
What I’ve decided to do is expose the sides of the big lug where it is crimped to the 3/0 or 4/0 negative cable and clamp my battery charger to the lug rather than adding a new piece.
I like your idea of making a bus for fittings and I may do that as one of my first mods to the system.
I may go solar, but first I want to gather more info on what I am able to reasonably do for keeping batteries charged with just the charger and little genset.
DrewE – Thanks for that explanation. I’m able to follow what you’re saying and it makes perfect sense. My father was an electrician, so I learned enough to do basic wiring, and I have a pretty good rudimentary understanding of electricity. But I also appreciate that there are factors that enter in that I may not be aware of, therefore, my inclination toward excess caution when I’m doing something for the first time. My whole purpose in posting this thread was to get validation from someone who knows this stuff better than I do for the solution that I had in mind.
Thanks again to everyone who replied!
Wayne
I measure the bolts at 5/8-inch and the threaded holes in the shunt at 1/2-inch. Factor in the lockwasher, the flatwasher, the big cable lug, we’re down to less than 3/8-inch of threads gripping. Add in a flattened copper pipe for clamping the charger and the grip gets down to about 1/4-inch. That makes me a bit nervous.
I’ve thought about substituting a longer bolt, but I don’t know what throwing a different metal into the mix will do the the electrical properties of the shunt, so I decided to play it safe and stick with the original bolt.
What I’ve decided to do is expose the sides of the big lug where it is crimped to the 3/0 or 4/0 negative cable and clamp my battery charger to the lug rather than adding a new piece.
I like your idea of making a bus for fittings and I may do that as one of my first mods to the system.
I may go solar, but first I want to gather more info on what I am able to reasonably do for keeping batteries charged with just the charger and little genset.
DrewE – Thanks for that explanation. I’m able to follow what you’re saying and it makes perfect sense. My father was an electrician, so I learned enough to do basic wiring, and I have a pretty good rudimentary understanding of electricity. But I also appreciate that there are factors that enter in that I may not be aware of, therefore, my inclination toward excess caution when I’m doing something for the first time. My whole purpose in posting this thread was to get validation from someone who knows this stuff better than I do for the solution that I had in mind.
Thanks again to everyone who replied!
Wayne
