Understanding bar

[VanKitten]

LWhat is a busbar?   Do I need one (or more)?
What is a neutral bar?   I see them in diagrams, but no explaination  how many do I need?

The deeper I dig into 12v wiring, the major thing I am learning is that I don't even know enough to know what I don't know.

 

[highdesertranger]

bus bar = a terminal strip where wires are connected. usually used for ground in a 12v system. more common in 120v AC systems where the neutral and grounds each have their own bus bar. do not use the 120v type bus bar in a vehicle use a terminal strip. here's a good bus bar for 12v,
https://www.amazon.com/Blue-Sea-Sys...UTF8&qid=1490882521&sr=8-2&keywords=buss+bars .
here is an example of 120v bus bar,
https://www.platt.com/platt-electri...und-Bars/Eaton/GBK14/product.aspx?zpid=271607 .
highdesertranger

 

[LoupGarou]

Consider battery terminals, you might need to make many connections to the positive post and a like number to the negative. Using busbars, you would only make a single connection from the battery post to the busbar. All the other connections would be made at the busbar.

 

[VanKitten]

If I am wiring from the battery terminals to the fuse panel (12v). Then from the fuse panel out to lights, fans, etc. isn't that just one connection anyway?

If I wanted more than one fuse panel...couldn't I "drop" the sub-panel from the first fuse panel? Then it is still one connection back at the battery post...yes?

 

[highdesertranger]

yes you can do it that way. like I said in 12v apps bus bars are most common for grounds and then for apps where you are dealing with fiberglass or wood and you must run separate grounds to a bus bar. but they can be used for any situation like a 12v hot distribution bus bar. highdesertranger

 

[John61CT]

More complex designs with monitoring shunts, control switching etc, may specify a charging buss separate from load busses.

The charge source voltage sensing wires and of course temp sensors must go direct to a battery terminal. And fuses close as possible.

 

[Weight]

Positive battery terminal, Blue Sea 5191 terminal fuse block, 2/0 cable, Blue Sea power bar common bus. The fused leads from the power bus to inverter, charging circuits, and other things such as fan, fridge, water pumps, and lights. Here are some links. https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A and https://www.bluesea.com/products/2307/Common_150A_BusBar_-_Four_1_4in-20_Studs_with_Cover I am using a heavier bus, 600 amp with 5/16 studs. I can't find the link.

 

[John61CT]

With that MRBF style fuse block, make sure it's well supported, a heavy cable will stress it.

Can find the same units as Samlex brand and others.

​Class T and ANL types can be easier to mount securely.

 

[Weight]

I have no problem with the MRBF fuse and block mounted on my battery terminal with 2/0 cables. It has been bouncing and rolling for over a year there. Blue Sea are heavily built and first class quality. I have a Samlex inverter, good stuff. I have not seen Samlex fuse stuff.

 

[DannyB1954]

 do not use the 120v type bus  bar in a vehicle use a terminal strip.

I have used these and have not had a problem. If fastened to wood, I have used them with inline fuses to feed circuits. I would not try to run 80 amps through them, but for a 30 amp service I see no problem. Why not use them?

 

[Spaceman Spiff]

The home buss bars are made to work with solid core wires.  The screw clamp doesn't work as well with stranded wire, unless the wire is soldered solid or constrained in a ferrule.

 -- Spiff

 

[VanKitten]

I'm sorry everyone, honestly...you lost me as soon as the terminology started to include acronyms. I am a true novice here....

Do I use a grounding bus or not? I will have about a possible max of about 80 amps (really max..I think). Going through two fuse panels. I think I will wire each separately coming from the battery. I will try to figure out how to get a battery monitor in too.

Since each fuse panel has grounding...and the bottom of the panel has return wire (grounding) going back on to the battery....do I put a ground bus there? Run it to the chassis from there or just back neg post of battery's.?

 

[highdesertranger]

sorry about the confusion. I sounds like you do not need a bus bar. it seems the fuse panel you are using has it's own bus bar built in. do you have a link to the fuse panel you are using? highdesertranger

 

[John61CT]

They have no special functionality, other than making it easier to terminate connections.

If you find you're putting more than 3-4 terminations on one stud, then you should use a buss.

Better to return to the battery than use the chassis only.

you lost me as soon as the terminology started to include acronyms. I am a true novice here....

When you see a term you aren't familiar with, google it. If it still doesn't make sense, ask, how you learn.

 

[Weight]

If you have a lot of wires that must connect together, you should use a bus bar. The negative connections on the fuse block is a bus bar.

 

[VanKitten]

I seem to have trouble getting the image to copy of link here....maybe too early in the morning for me.

Anyway .. it is the blue sea 6 fuse blade with neg bus.

If it is the wrong thing...I can get another ordered quickly enough. Wire should arrive by Monday...so it will be a while before I have the rough wire laced through the stud and civil joists (rafters).

 

[LoupGarou]

Does this help?

 

[LoupGarou]

Does this help?

Let's try this again. For some reason jumping between this site and Photo Bucket didn't work.

See the below thread and my response #6 for a good example on using buses.

https://vanlivingforum.com/Thread-Electrical-install-near-Barstow-CA?pid=128447#pid128447

 

[DannyB1954]

The home buss bars are made to work with solid core wires.  The screw clamp doesn't work as well with stranded wire, unless the wire is soldered solid or constrained in a ferrule.

 -- Spiff

I learned a trick many years ago from Popular Mechanics I believe. 
Strip the end of the wire twice as long as you need it. Now separate the wires into two groups so that they look like the letter L
Take the wires that come out straight and twist them in one direction. Then you can fold them in half, (so the diameter is twice). 
Now take the other wires and wrap them around the first set but in the opposite direction. 
Cut off any of the first set that protrude.

When you put them under a screw the opposing forces of the twists will keep them solid.

 

[Weight]

Those house panel grounding/neutral buses are not good to use with DC amps. Maybe a circuit needing but 1 amp. But voltage drop is a big problem in DC battery systems.