I need help selecting a busbar size

[Santa]

Can someone please help me select a busbar size for this arrangement of Will's? https://www.mobile-solarpower.com/400-watt-w-alternator-charging.html I am getting a 300 amp ANL main fuse for the circuit breaker, if that even matters. I didn't see it in Will's book. TY

 

[Nomadic Diesel]

https://www.amazon.com/Bay-Marine-Supply-BusBar-Distribution/dp/B075XCMC2T/ref=sr_1_fkmr0_1?keywords=Bay+Marine+BusBar+-+4-Post+Power+Distribution+Block+-+Pair+of+5%2F16%22+Black+%26+Red&qid=1573872638&sr=8-1-fkmr0

 

[Santa]

https://www.amazon.com/Bay-Marine-Supply-BusBar-Distribution/dp/B075XCMC2T/ref=sr_1_fkmr0_1?keywords=Bay+Marine+BusBar+-+4-Post+Power+Distribution+Block+-+Pair+of+5%2F16%22+Black+%26+Red&qid=1573872638&sr=8-1-fkmr0

In Will's blueprint there is only 1 of those, so where (and why) would I need two?

 

[Nomadic Diesel]

Why two? One for the positive cables and one for the negative cables, common and chassis ground. I have not viewed Will's diagrams. No need, my system is already installed.

 

[Santa]

Why two? One for the positives and one for the negatives plus common plus chassis ground. I have not viewed Will's diagrams. No need, my system is already installed.

That's a little over my head. ty

 

[Nomadic Diesel]

If Will's diagram does not include a positive and negative buss bar I would suggest you look elsewhere like here: https://www.explorist.life/solarwiringdiagrams/

 

[Santa]

If Will's diagram does not include a positive and negative buss bar I would suggest you look elsewhere like here: https://www.explorist.life/solarwiringdiagrams/

Ha! $40 a month, no thank you.

 

[CheezWiz]

Please keep discussion civil. Remember we all have different levels of knowledge and skills. We're here to help each other out, not attack one another for not knowing something.

 

[Nomadic Diesel]

The wiring diagrams are free.

 

[Santa]

The wiring diagrams are free.

Custom wiring diagrams $40 a month

 

[Santa]

The wiring diagrams are free.

Just nevermind

 

[CheezWiz]

@Santa the suggested link is a solid choice. The black one for negative and the red one for positive. Thinking about the function of a bus bar, it allows us to safely connect high current wires together. The selection requirements will be dictated by your loads. I'm about to nod off at the moment but I'll be back in the morning to try and clear up your question.

 

[Santa]

@Santa the suggested link is a solid choice. The black one for negative and the red one for positive. Thinking about the function of a bus bar, it allows us to safely connect high current wires together. The selection requirements will be dictated by your loads. I'm about to nod off at the moment but I'll be back in the morning to try and clear up your question.

I understand positive and negative, but why didn't Will use 2 in his blueprint? Its just confusing to add something I have no idea how to place it. Sweet dreams.

 

[gnubie]

He's used the breaker terminal as a interconnection point. Since there's only a limited number of things in the mix - battery/inverter/charger - its a fair enough thing to do. If you had more devices a bar for + distribution would be the way to go.

 

[Will Prowse]

You can use 2 bus bars, or 4, or whatever works for your components. Depends on how much space you have, and how many things you wish to connect. As long as everything is rated to carry the load, you can wire it however you wish.

I think I should make a video about this. Have seen a few questions about it. I think it is because people just want a direct blueprint to follow. But every system is different and it really depends on what is being connected. And yes, using a circuit breaker as an interconnection point works great. But it needs to be calculated to work for the components/wire so OCPD can protect wire and component from short circuit or overload situation.

 

[CheezWiz]

When it comes to busbars, short answer could be "Trust me from experience, you want more than one." and a longer answer follow-up "When it comes to using DIY solar, you never seem to have enough spots to hook stuff up, because you will regularly be adding, changing, reconfiguring, etc.."

Coming from a background in ham radio, we never use chassis ground for anything. We always run a ground wire back to the battery for anything. That is where a negative bus bar comes in. I don't want a bunch of wires hanging off the battery ground, so a single wire to a busbar is a better choice for me. Same for the positive side.

 

[CheezWiz]

@Santa what sort of loads are you looking at servicing? Never hurts to buy a busbar bigger than needed as they are relatively inexpensive.

 

[Santa]

You can use 2 bus bars, or 4, or whatever works for your components. Depends on how much space you have, and how many things you wish to connect. As long as everything is rated to carry the load, you can wire it however you wish.

I think I should make a video about this. Have seen a few questions about it. I think it is because people just want a direct blueprint to follow. But every system is different and it really depends on what is being connected. And yes, using a circuit breaker as an interconnection point works great. But it needs to be calculated to work for the components/wire so OCPD can protect wire and component from short circuit or overload situation.

That would be great if you did a video Will. I am trying to follow your blueprint to a T. So, should I buy a 250a busbar (that's the maximum it shows)? I clicked the link in your blueprint to select one, but I don't know which amperage to select. Looking forward to a video when you have time. Thank you for all you do!

 

[Will Prowse]

I am making a new blueprint and board set up @Santa

 

[Steve_S]

I am making a new blueprint and board set up @Santa

A slight suggestion will. Apply the "Rule of Three". If you are asked the same question 3 times or more, it's time to write it up as one answer and post it to a "Sticky", reference section or FAQ list. This way when the Q is asked again, just point them there. It keeps things consistent, easier to update and saves a heap of time & effort as well. Much more fun ripping apart a pack than typing answers all day no ?