How Victron Multiplus connects to breaker panel?

**joe6789** · 10-02-2019, 04:06 PM

Need some help installing my Victron Multiplus 2000w inverter/charger on a 50A Reflection. I'm unclear how the circuit breaker panel relates to the AC-in and AC-out on the Multiplus.

Should the shore power cable go into the circuit breaker panel, then run a cable from breaker panel to Multiplus AC-in, then another cable from Multiplus AC-out back to the breaker panel? Or should I skip the breaker panel on the way in and go direct from shore power to Multiplus AC-in?

I understand my 50a rig has two 50a AC legs, and that (without installing something more sophisticated) the inverter on the Multiplus can only power one of the legs. That's fine with me -- I don't need the inverter for much. But it does seem to complicate the installation. I'm wondering if I'm supposed to run one leg of shore power to the breaker panel and the other leg to the Muliplus, and then a cable from the Multiplus AC-out to the breaker panel's second leg.

I've seen some info online about installing a second circuit panel or sub-panel, but that seems more ambitious than my skillset allows. I'm really looking for the simplest solution.

A few notes: I will also be installing two 100aH Battle Born lithium batteries and the BMV-712 battery monitor (but not the Digital Multicontrol or Color Control). I later plan to install about 400w of solar and an MPPT controller, though wanted to tackle this battery + inverter upgrade first.

Thanks!

**cookinwitdiesel** · 10-03-2019, 02:15 PM

Originally Posted by joe6789

Need some help installing my Victron Multiplus 2000w inverter/charger on a 50A Reflection. I'm unclear how the circuit breaker panel relates to the AC-in and AC-out on the Multiplus.

Should the shore power cable go into the circuit breaker panel, then run a cable from breaker panel to Multiplus AC-in, then another cable from Multiplus AC-out back to the breaker panel? Or should I skip the breaker panel on the way in and go direct from shore power to Multiplus AC-in?

I understand my 50a rig has two 50a AC legs, and that (without installing something more sophisticated) the inverter on the Multiplus can only power one of the legs. That's fine with me -- I don't need the inverter for much. But it does seem to complicate the installation. I'm wondering if I'm supposed to run one leg of shore power to the breaker panel and the other leg to the Muliplus, and then a cable from the Multiplus AC-out to the breaker panel's second leg.

I've seen some info online about installing a second circuit panel or sub-panel, but that seems more ambitious than my skillset allows. I'm really looking for the simplest solution.

A few notes: I will also be installing two 100aH Battle Born lithium batteries and the BMV-712 battery monitor (but not the Digital Multicontrol or Color Control). I later plan to install about 400w of solar and an MPPT controller, though wanted to tackle this battery + inverter upgrade first.

Thanks!

That is the right approach. I recommend having a junction box with bus bars for neutral and ground where you split and recombine the 6/3 cable into separate legs before and after the inverter to keep it clean going to shore power and to the breaker panel.

Remember that only one side of your breaker panel will be powered by the inverter so you may want to move some circuits/breakers around to make sure you have power where you need it while off the grid. If you want to add a 2nd inverter down the road you would just mirror the setup on the other hot leg.

I also recommend reaching out to a solar integrator or BattleBorn themselves to get some consultation on your install as there are some details you do not want to guess on to make sure everything is safe.

**jungleb0y** · 10-03-2019, 09:42 PM

An easy install would be to go to the big box store and pick up enough 6/3 cable to run from where ever you're going to install the multiplus, this new cable you will take one end and feed it into your panel and disconnect the side on the panel that you want to have power from the inverter and then connect that to the black wire going to your multiplus (use an aluminum splicer/reducer and wrap that in rubber tape and then electrical tape), connect the red to the spot which you removed from the panel, and then connect the neutral (white) and ground (bare) to the blocks in the panel.

Fish that cable through your rig to where the multiplus is going to be residing and just before there put a junction box (ideal would be a dual 50A breaker panel one for both the feed (black) and return (red)) do the following.

From the multiplus on both neutrals for ac-in and ac-out run a 6awg line to the panel/junction and connect them with either a split bolt or on a terminal block to the neutral coming from the panel, do the same for the grounds but this can be a 8awg i believe.

For the ac-in on the multiplus run a 6awg line to the black cable coming back from the panel (if you use a breaker connect it through the breaker) connect it with a split bolt.

For the ac-out on the multiplus run a 6awg line to the red (return) cable coming back from the panel (if you use a breaker connect it through the breaker) connect it with a split bolt.

You might also want to run the ethernet cable for the 712 along side of the 6/3 cable and put the panel for that somewhere near the breaker panel or if you have other plans for that you can do whatever with it as it's bluetooth as well and you can see it from your phone so no real reason to have it installed except for ease not having to whip out the phone to check it.

On my install on the 315 under the hutch by the panel I installed a contactor that switches power to the second leg on the panel based on if there is power in the shore power cable or not.

That's my 25¢

Additionally, all split bolts and splices need to be wrapped in rubber tape with an electrical tape exterior, you can search youtube to learn how to do that.

**joe6789** · 10-06-2019, 01:13 AM

Thanks cookinwitdiesel and jungleb0y. Both explanations were helpful. If others read this thread in the future, another good description of this methodology is at the following link in the "Splitting" a 50-ampere Load Center section: http://www.jackdanmayer.com/Wiring.html

I think my plan is to leave one leg (black) as it is currently installed going into the breaker panel. But I'll disconnect the other leg (red) from the breaker panel, splice it into a longer cable inside a junction box, and run that extended red cable into the inverter. And then put a new red cable from the inverter back to the breaker panel to the exact spot where I had disconnected it.

The part I'm less certain about is the neutral and ground. I'll repeat what I did for the red leg for the neutral and ground as well (disconnecting them from the breaker panel, splicing into longer cables which run into the inverter, and then back to the breaker panel). But that means the black leg (the side NOT connected to the inverter) will enter the breaker panel with no neutral or ground wires. Yes, the neutral and ground eventually make it into the breaker panel after passing through the inverter, but I'm not certain if that's acceptable, or if instead the black leg needs it's own neutral and ground that don't pass through the inverter.

**jungleb0y** · 12-18-2019, 09:24 PM

Sorry for such a late reply on this (you have probably already completed this), I don't make it around here very often.

I don't personally see the need for an additional junction box at the panel side as that is what the panel is there for and has more than enough room inside it to contain the new 6/3 cable which houses all of the wires you need that will run to and from the inverter, a supply and return a neutral and ground (these just make a link), the neutral can be combined at the inverter for the ac-in and ac-out feed at the inverter a well as the ground's (except of course 2 of the same color wires which can be corrected with electrical tape in our case red, as was mine).

The only place I will suggest you put a additional junction box would be at the inverter to make the combination of the Neutral and Ground as there isn't sufficient room inside the inverter to do this. As I mentioned before I also recommend making this junction box a dual position breaker panel so that you can put 2 50 amp breakers in it to protect the supply and feed lines coming from shore and to your panel.

**jungleb0y** · 12-18-2019, 09:31 PM

Originally Posted by joe6789

The part I'm less certain about is the neutral and ground. I'll repeat what I did for the red leg for the neutral and ground as well (disconnecting them from the breaker panel, splicing into longer cables which run into the inverter, and then back to the breaker panel). But that means the black leg (the side NOT connected to the inverter) will enter the breaker panel with no neutral or ground wires. Yes, the neutral and ground eventually make it into the breaker panel after passing through the inverter, but I'm not certain if that's acceptable, or if instead the black leg needs it's own neutral and ground that don't pass through the inverter.

Sorry just read this again, your not going to be disconnecting the ground or neutral from the existing shore power connection, you want to tie into the existing bus bars that are inside the panel and run those up to the inverter hence the need to only use the 6/3 which has the 3 6awg cables and the 8awg ground.

Edit: reason is if something happened at your inverter your are going to be isolating the other leg coming from shore and will then have an open neutral and no ground.

**BB&LAB** · 12-19-2019, 08:50 AM

I purchased from Amsolar their Smart ATS box which made the install easier and works seemlessly with my Victron Multiplex 3000K

**cookinwitdiesel** · 12-19-2019, 08:54 AM

This diagram shows what sort of wiring would need to happen on the AC side.

You can see the 2 boxes used to break apart and recombine the main 6/3 cable before and after the inverter. The other stuff is specific to my plan and may not be relevant to you but focus on the AC wiring.

**jungleb0y** · 12-19-2019, 11:04 AM

Originally Posted by BB&LAB

I purchased from Amsolar their Smart ATS box which made the install easier and works seemlessly with my Victron Multiplex 3000K

That powers both sides of the panel in your situation too right?

**Ed and Cathy K** · 12-19-2019, 02:14 PM

I used a contactor with a 120VAC coil that I connected to the 2nd leg before my hard wired EMS. The EMS has a built in timer that permits the contactor to be in the position before power is applied.