Bus Bars / Distribution Panel

[gmflash88]

If I'm putting (or thinking/planning on putting) a distribution panel for AC and DC power in my bus, do I also need bus bars? Aren't I accomplishing the same task through the use of the panel?

Sorry if that's the dumbest question you've read today.

Thanks!

[rossvtaylor]

Well...not the dumbest...but the day's not over yet.

Anyway, I'm glad you asked. Electrical stuff isn't worth guessing over, so we appreciate the questions!

Bus bars are only for common connections, like AC neutrals or grounds. You would never use a bus bar for "power" wires (lines or hots... or positives for DC), because each of those should be protected by a fuse or breaker.

Tell me, and us, more about your plan and there are lots of folks here who will help you.

[bigskypc50]

A distribution panel is just a fancy bus bar with fuses or breakers. A bus bar is more for solar or dc stuff after the protection device, such as say you have 15 led light strips and you have 15 wires that’s to much for one connection on the fuse. You would instead run wire from the fuse to bus bar then wire the 15 led leads to that

[rossvtaylor]

bigskypc50 makes a good point...so I guess that emphasizes my desire to clarify what you mean. In the case of what bigskypc50 describes, I'd think of that as a terminal strip or a terminal block where you can connect multiple devices to one protected circuit. In my feeble mind, a bus bar is different. Probably, that's just me? Either way, tell us more about your proposed layout and we'll help you set it up right.

[bigskypc50]

We are going to confuse the guy, LOL when I hear terminal strip I think of say 15 non interconnected connection points.

https://www.newtechindustries.com/16...0-volts-ac-dc/

Originally Posted by rossvtaylor

bigskypc50 makes a good point...so I guess that emphasizes my desire to clarify what you mean. In the case of what bigskypc50 describes, I'd think of that as a terminal strip or a terminal block where you can connect multiple devices to one protected circuit. In my feeble mind, a bus bar is different. Probably, that's just me? Either way, tell us more about your proposed layout and we'll help you set it up right.

[gmflash88]

Originally Posted by bigskypc50

A distribution panel is just a fancy bus bar with fuses or breakers. A bus bar is more for solar or dc stuff after the protection device, such as say you have 15 led light strips and you have 15 wires that’s to much for one connection on the fuse. You would instead run wire from the fuse to bus bar then wire the 15 led leads to that

Well, on that note...by my count, I'll have the following:

AC Circuits - (1) 20a to rooftop AC Unit (shore power only), (2) 20a feeding left and right side of bus receptacles.

DC Circuits - (1) to 12v fridge/freezer, (1) to 2 LED strips, (2) to feed USB receptacles on left and right side of bus, (1) to water pump, (1) to water heater (ignition), (1) to diesel heater, (1) to max air fan

I'm sure I'm missing something. With that in mind, would the distribution panel do that just fine without bus bars and a bunch of inline fuses? Sorry if I'm not following. I'm the furthest thing from an electrician!

[bigskypc50]

I assume you will have an inverter with some kind of transfer switch in it? In that case you would do this shore power to inverter, inverter out to ac Circuit breaker panel then your Ac panel with your three ac breakers then Out to the air con and outlets make sure your inverter can pass the air con power too.

The dc side is were your bus bars come into play,

That would be like this Battery’s neg to neg bus bar, battery pos to master disconnect then to pos bus bar. Then your inverter charge controller and DC distribution panel from those bus bars. You would want like a blue sea 12v pannel. Also fuse pos leads from pos bus bar.

Attached is mine

Originally Posted by gmflash88

Well, on that note...by my count, I'll have the following:

AC Circuits - (1) 20a to rooftop AC Unit (shore power only), (2) 20a feeding left and right side of bus receptacles.

DC Circuits - (1) to 12v fridge/freezer, (1) to 2 LED strips, (2) to feed USB receptacles on left and right side of bus, (1) to water pump, (1) to water heater (ignition), (1) to diesel heater, (1) to max air fan

I'm sure I'm missing something. With that in mind, would the distribution panel do that just fine without bus bars and a bunch of inline fuses? Sorry if I'm not following. I'm the furthest thing from an electrician!

[gmflash88]

Originally Posted by bigskypc50

I assume you will have an inverter with some kind of transfer switch in it? In that case you would do this shore power to inverter, inverter out to ac Circuit breaker panel then your Ac panel with your three ac breakers then Out to the air con and outlets make sure your inverter can pass the air con power too.

The dc side is were your bus bars come into play,

That would be like this Battery’s neg to neg bus bar, battery pos to master disconnect then to pos bus bar. Then your inverter charge controller and DC distribution panel from those bus bars. You would want like a blue sea 12v pannel. Also fuse pos leads from pos bus bar.

Attached is mine

I think I'm getting it. Yes, I will have a inverter charger. So my inverter needs to have enough power for the AC? My intention is a 2500w but I was hoping to connect the AC to shore power directly and not have to pass through the inverter. My rudimentary set up (without fuses/dist panel illustrated) is below.

EDIT: Looks like the running wattage will be 1650w so I should be goo through the inverter. Was just hoping to not put the load on it. Not sure if that matters or not.

[bigskypc50]

No your inverter don’t have to be able to power the Air Con just be able to pass the power on. Two diff stories. If you wanted to run the AC unit from shore power only you would need a 2nd AC Circuit breaker panel then you would have this setup shore power to 1st ac panel two breakers one to Air con then 2nd to inverter/changer. Then to post inverter ac pannel. and two more ac breakers for left and right sides. Un needed cost and parts

Edit: You would just not turn on the. Air con unless you had shore power connected. Look at the transfer switch specs on your inverter just don’t pull more then it can pass on

[gmflash88]

Originally Posted by bigskypc50

No your inverter don’t have to be able to power the Air Con just be able to pass the power on. Two diff stories. If you wanted to run the AC unit from shore power only you would need a 2nd AC Circuit breaker panel then you would have this setup shore power to 1st ac panel two breakers one to Air con then 2nd to inverter/changer. Then to post inverter ac pannel. and two more ac breakers for left and right sides. Un needed cost and parts

Got it. That helps a lot!

I literally just bought the bus two weeks ago and have it parked (wouldn't start today...could be that it's -15 here or that I left something turned on in the 37 switches that I don't know what they do). I'm a ways away from getting to electrical, but I'm a planner!

That and I have a buddy who does low voltage work for large commercial projects and residential electrical on the side and the sooner I can get him a list of materials, the more time I have for all the odds and ends that might "fall off the truck" lol.