Making busbars

**Improvised DIY** · Mar 27, 2022, 08:32 AM

Making busbars for my Li-ion batteries.

**nova_robotics** · Mar 28, 2022, 09:45 PM

Neat. I'd use those on ONE side of those ganged breakers. Both sides is daring Death to remove you from the census.

**Frank S** · Mar 28, 2022, 10:58 PM

I have a couple of mig welders with magnetic contactors in them the contactors in the machines when new were just 40 amp 2 pole with buss bars on both sides and would wear out rather quickly in 1 of the machines, so I went to 70 amp 2 pole, which lasted longer but still I felt the contacts were undersized. The largest contactor that would physically fit in the space was a 3 pole rated for 100 amps I made buss bars for it. That contactor has been in there for 4 years and I have a spare on the shelf for when it finally fails. The other machine is smaller but is seldom used at its max amps so the 70amp contactor I put in it has been working fine for quite a while now

**DIYer** · Mar 29, 2022, 04:52 AM

Thanks Improvised DIY! We've added your Busbars to our Electrical category,
as well as to your builder page: Improvised DIY's Homemade Tools. Your receipt:

Busbars by Improvised DIY

tags: electrical

**Improvised DIY** · Mar 29, 2022, 10:16 AM

I see you are quite busy around the shop. My neighbour was still doing carpentry at age 95. He lived till 105. Sometimes machines are designed with too tight tolerances to save cost. That's why they fail. I usually design my electronics to work to a 60-80% of rated capacity of the components.

**Improvised DIY** · Mar 29, 2022, 10:26 AM

Only for display purposes. You can parallel 63amp 3-pole breakers to divide the load if you don't want to go broke with a single pole breaker of 180 -200amp. Your PCC is also tripled.

**Ralphxyz** · Apr 3, 2022, 05:54 PM

How many batteries and what amperage that would use a 1/4"+ busbar?

Ralph

**Frank S** · Apr 3, 2022, 07:11 PM

Originally Posted by Ralphxyz

How many batteries and what amperage that would use a 1/4"+ busbar?

Ralph

The busbar in this case is more of a bridge between the 3 poles of the circuit breaker, The amperage of the breaker would be the limiting factor. The number of batteries are irrelevant as long as you are not trying to use a breaker of this type to parallel batteries together it is for down stream output only never as an inter bank connector. circuit Breakers are also not meant to be used as switches while under load

**Improvised DIY** · Apr 4, 2022, 04:58 AM

My busbars are good for 120 amp per pole. In my case I am using lithium ion batteries which has low output current compared to lead acid. On your breakers there would be an IC rating usually between 3 and 15kA. That is a limiting factor on the breakers when using batteries. Lead acid can exceed 1000Amps easily under short circuit conditions. Always make sure that your total CC currents of your batteries do no exceed the IC ratings of you breakers. The busbars you have should have a current rating stamped on it unless you made it yourself. There is is quite a lot of considerations to take into account like temperature, insulation, enclosure type etc. which influence the outcome. There are charts available to put you in the ball park.