I need help selecting a busbar size

Steve_S · Nov 17, 2019

Will Prowse said:
Blueprint is now updated: https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

Excellent Will ! gotta love simple, no way around that.
Question. Assuming the alternator is the same as used for the vehicle itself and it's 12V battery, would this not overrun the alternator if it was loaded running heater/ac or charging the vehicle battery as well ? Now in an older non-computer vehicle, it's not a big deal to go from an 80A to 120A alternator, tad more tricky with computerised cars but not crazy hard either.

BTW in the last couple of years, the "jobber rebuilt alternators" have become junk due to the cheapness of parts, if anyone is looking for a good unit, ensure you get an original (out of a wreck) or a Factory Rebuilt one, which will cost a bit more than the jobber ones but will last.

Will Prowse · Nov 17, 2019

yes, but on the blueprint, it wont matter what size you choose because the lugs are touching each other. You could use a small bus bar and it would work fine. Thats why its wired like that.

And yes, use both of them as suggested in package

Will Prowse · Nov 17, 2019

Steve_S said:
Excellent Will ! gotta love simple, no way around that.
Question. Assuming the alternator is the same as used for the vehicle itself and it's 12V battery, would this not overrun the alternator if it was loaded running heater/ac or charging the vehicle battery as well ? Now in an older non-computer vehicle, it's not a big deal to go from an 80A to 120A alternator, tad more tricky with computerised cars but not crazy hard either.

BTW in the last couple of years, the "jobber rebuilt alternators" have become junk due to the cheapness of parts, if anyone is looking for a good unit, ensure you get an original (out of a wreck) or a Factory Rebuilt one, which will cost a bit more than the jobber ones but will last.

Oh it could damage the alternator. But if its a van/rv/truck etc, it will handle it no problem. It is a smart dc dc charger with temp comp and current limiting. And if you have solar, it likes to decrease alternator charging to 25 amps. Which even a car alternator can handle.

Santa · Nov 17, 2019

Will Prowse said:
Blueprint is now updated: https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

OK, now I see the pic says to use 250A busbar. Thanks for taking the time to do this today Will! You're the best!

Rootboy · Nov 17, 2019

What we are really talking about is a "Power distribution block". That makes finding them on the web easier. ;>

Here's one that ought to do:

Galco

www.galco.com

After posting this I got to wondering about its suitability for use with aluminum wire. You have to go to the Erico site for the information, but they are suitable for use with aluminum.

Santa · Nov 17, 2019

Rootboy said:
What we are really talking about is a "Power distribution block", that makes finding them on the web easier. ;>

Here's one that ought to do:

Galco

www.galco.com

After posting this I got to wondering about its suitability for use with aluminum wire. You have to go to the Erico site, but they are suitable for use with aluminum.

Will said to get a 250 Amp. It looks pretty though! ty

erik.calco · Nov 18, 2019

@Santa I'm debating a DC panel with breakers because it is starting to look economical as well as being an all-in-one. But, this is for home, not vehicle, where space isn't as limited. I'll still have a big fuse within 7" of battery bank (+) because that's there to protect the bank and its wires.

Santa · Nov 18, 2019

erik.calco said:
@Santa I'm debating a DC panel with breakers because it is starting to look economical as well as being an all-in-one. But, this is for home, not vehicle, where space isn't as limited. I'll still have a big fuse within 7" of battery bank (+) because that's there to protect the bank and its wires.

DC Panel? I am following Will's blueprint (he updated it yesterday).

erik.calco · Nov 18, 2019

Santa said:
DC Panel? I am following Will's blueprint (he updated it yesterday).

I'm sure it's overkill for what you're doing, but a DC Breaker Box would combine a bus bar and breakers for DC distribution in one. It opens the door to using those pop in breakers instead of having a stand alone breaker for each inverter or w/e distribution you add to your battery bank. It seems economical because for w/e reason, the standalone breakers seem to cost a lot more than the pop-in ones, in part because they need more protective housing. But, I'm just starting to look into it.

EDIT: Some of them come with a battery (-) bus bar, too.

I'm also looking for ways to limit or contain risk, and that is cultivating an appreciation for metal boxes.

Kiwi DIYer · Nov 19, 2019

Hi, I have had 2 bus-bars made at a local elections hardware manufacturer. They are rated to 500 amps, twice the rating of my 250 amp main fuse. From these I will be attaching the solar controller, the inverter and battery wire's.
Just picked up the 2 bus-bars that I had made. They have an isolation mounting volt and are confirmed to be rated at 470 amps guaranteed.

I need help selecting a busbar size

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada

Will Prowse

Forum Owner

Will Prowse

Forum Owner

Santa

.

Rootboy

New Member

Galco

Santa

.

Galco

erik.calco

Solar Badger

Santa

.

erik.calco

Solar Badger

Kiwi DIYer

New Member

Attachments

Similar threads