Magnum 3000w inverter in 50amp system

[unyalli]

If I go the expensive route I will install a Magnum MSH-3012-M Hybrid PSW inverter/charger. I would want the ability to run the entire RV (not all at once of course) via this unit so would have to re-wire. Looking at WFCO's manual for the 8950/30 power distribution panel it looks like the right hand 50 amp breaker powers the breakers to the right of it and the left hand 50 amp breaker powers the breakers to the left of it.


I would have to switch the GFI and water heater so all my outlets were on the right hand 50 amp breaker. Next replace the full width 20 amp breaker for the main air conditioner with a double 20 like the ones way over on the left and reconnect the Ac to one of the new 20 amp breakers and move the micro to the other. Now I would have everything I will ever use on the "red leg" and would wire it through the inverter utilizing it's built in 60 amp transfer switch. Sound about right so far?


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I would have all the left hand breakers off all the time as I would not use any of that stuff. I all ready have the ac plug from my refrigerator unplugged so it can never run on ac. The magnum manual states "The AC input and output neutrals must be isolated from each other, do not route the AC input and output neutrals to a common neutral bus." When I take the red leg loose from it's 50 amp breaker and extend it to the inverter with a length of 8/2 wire I would connect the neutral of this new wire to the neutral bus in the picture and the ground to the ground bus. Now with a second new length of 8/2 I would connect from the inverters ac output with the hot (black) going to the right hand 50 amp breaker but where will the neutral go?

Jeff

P.S. I never stated I planned on running my air conditioner off my batteries.

[Old Bounder]

The re-wiring is going to be a bit more complex than you first thought. You need to separate the neutrals of the "left" side circuits from those on the "Right" side. You'll then have two neutral bars. The second neutral bar is where you connect the Inverter T/X switch neutral.

[unyalli]

Originally Posted by loulong

The re-wiring is going to be a bit more complex than you first thought. You need to separate the neutrals of the "left" side circuits from those on the "Right" side. You'll then have two neutral bars. The second neutral bar is where you connect the Inverter T/X switch neutral.

I see it. Quite simple actually. Thanks loulong.

Jeff

[Scottybdivin]

I'm following this thread with some of the same ambitions as the OP. Thanks for posting such clear and precise photos. I will like to see how you separate the neutral bus bars. Also to the OP, you mentioned leaving all the left side breakers off, which after re-wiring includes your 2nd AC, water heater, fireplace, and W/D. I assume you mean only when dry camping? You will still have your main AC, Micro, and receptacles on the red leg but have no intention of running the AC off of the batteries. What is your reasoning for wanting the Hybrid vs the standard MS Series?

Thanks

[EngineerMike]

You can buy neutral buss "kits" at HD, Lowes, & electrical supply joints. Might want to replace a long one w/two shorts or add a new one.

Although it may look like left/right, i.e. all brkrs to left are fed by Black leg, to right by Red leg, that could easily be hokum. Could also be that from extreme left you have RR, BB, RR, B, R, BB, R where the double consonants are for Red-Red or Blk-Blk dbl (wafer) breakers and singles are for Red or Blk single standard case brkrs. In other words I'd guess its more likely that the legs alternate across the whole line of brkrs. Could be as OP stated however. Just pull the brkrs (they should pop out from the top) & check how the busses work.

FYI in rigs that come w/a high end charger/inverter like the Magnum, the usual "one-line" looks like this:
1- gen/shore-cord transfer switch into main panel breaker
2- 30A brkr in panel OUT to inverter/charger
3- transfer switch in inverter/charger (chooses between returning incoming 120V shore or gen, or send invertered 120v from batteries when no 120V input present) out to
4- sub-panel just for inverted circuits and with its own N buss
Given your "input" of inverter 120V to the Red leg of the coach panel, I don't see how you will get 120V to the inverter/charger to charge batteries, and you haven't clarified what you are doing w/the Red leg input from shore or gen. Seems like there are some bugs to work out here.

If you have room for an inverter sub-panel, this would keep the installation more industry standard (you'd arrange a single brkr out to inverter, then inverter back to sub-panel w/brkrs for inverted or passed thru shore/gen voltage). What you are discussing is way-not-standard as it disrupts the 240V incoming service that is branched out in a standard RVIA type wiring scheme expected by tech's encountering a 50A/240V RV input.

[unyalli]

Originally Posted by Scottybdivin

I will like to see how you separate the neutral bus bars.

I will in fact have to separate the neutral and ground bus bars. Figure I will remove them and cut them in half with a high speed cutoff wheel then take 1/4 inch from one of them so there's a gap when reinstalled. All the hot's going to the left (black) side will have their neutrals and grounds on the left as well as incoming shore neutral and ground. I may epoxy a plastic separator of some type in between them for over kill.

Originally Posted by Scottybdivin

Also to the OP, you mentioned leaving all the left side breakers off, which after re-wiring includes your 2nd AC, water heater, fireplace, and W/D. I assume you mean only when dry camping?

Correct which is pretty much all I do. I don't have a second air conditioner or washer dryer. Sure wish there was an externally vented gas fireplace to replace the electric one.

Originally Posted by Scottybdivin

You will still have your main AC, Micro, and receptacles on the red leg but have no intention of running the AC off of the batteries.

Correct, IF (and that's a big if) I run the air conditioner I will provide around 10 to 12 amps AC from my Champion 2000i inverter generator and over 500 watts DC of solar. The MSH will combine these to run the AC loads including the air conditioner. When the compressor starts the MSH will grab the extra watts from the DC side and if it dips into the batteries for this few seconds that is ok.

Originally Posted by Scottybdivin

What is your reasoning for wanting the Hybrid vs the standard MS Series?

It's all about the hybrid. Check out page 32 (load support) of the MSH-M Manual. This is what makes the hybrids different. Victron makes units that do this as well. Xantrex does not. I prefer the made in USA magnum.

Jeff

[unyalli]

Originally Posted by EngineerMike

Just pull the brkrs (they should pop out from the top) & check how the busses work.

Before spending any money I will absolutely do this and verify the documentation is correct.

Originally Posted by EngineerMike

If you have room for an inverter sub-panel, this would keep the installation more industry standard (you'd arrange a single brkr out to inverter, then inverter back to sub-panel w/brkrs for inverted or passed thru shore/gen voltage).

I know, but a sub panel will require buying it (not a big deal) cutting into my wall to mount it, then running all the wiring to it. I may have to extend the wiring of some of the circuits so they reach. To me what I'm envisioning is simpler. Should I ever need to return the unit to stock I will pull out all my stuff, reconnect the red leg to it's 50 amp breaker then install some 8 awg jumpers in the split bus bars connecting them back together.

Jeff

[ernieh]

Originally Posted by unyalli

Before spending any money I will absolutely do this and verify the documentation is correct.


I know, but a sub panel will require buying it (not a big deal) cutting into my wall to mount it, then running all the wiring to it. I may have to extend the wiring of some of the circuits so they reach. To me what I'm envisioning is simpler. Should I ever need to return the unit to stock I will pull out all my stuff, reconnect the red leg to it's 50 amp breaker then install some 8 awg jumpers in the split bus bars connecting them back together.

Jeff

You forgot to add that you will be violating the NEC and voiding your insurance as well. What "works" isn't always what's "right".

One of my greatest fears when I worked in the electrical trades was a building that had been wired by an "engineer" not an electrician.

Almost everything in the NEC is there because someone, somewhere got hurt or died when it wasn't followed.

[unyalli]

Originally Posted by ernieh

You forgot to add that you will be violating the NEC and voiding your insurance as well. What "works" isn't always what's "right".

One of my greatest fears when I worked in the electrical trades was a building that had been wired by an "engineer" not an electrician.

Almost everything in the NEC is there because someone, somewhere got hurt or died when it wasn't followed.

True True. Hmmmm.....

[unyalli]

Originally Posted by ernieh

You forgot to add that you will be violating the NEC and voiding your insurance as well. What "works" isn't always what's "right".

One of my greatest fears when I worked in the electrical trades was a building that had been wired by an "engineer" not an electrician.

Almost everything in the NEC is there because someone, somewhere got hurt or died when it wasn't followed.

So let's explore this sub panel topic. The only one I've found so far is the 30 amp 5000 series by progressive dynamics the guys that make my PD9245C. I might be able to mount this in the wall right next to or above the existing panel for a factory look and hopefully the wiring will reach. Is there a smaller panel out there with AC only?

[Old Bounder]

Originally Posted by unyalli

So let's explore this sub panel topic. The only one I've found so far is the 30 amp 5000 series by progressive dynamics the guys that make my PD9245C. I might be able to mount this in the wall right next to or above the existing panel for a factory look and hopefully the wiring will reach. Is there a smaller panel out there with AC only?

It doesn't have to be an RV sub panel. Check the ones available at Lowe's and HD. Do a search for sub panels.

You really do need to consider this approach. As you have described your approach, you are eliminating a main breaker on the red lead of your incoming power. That's not a good thing.

With a sub panel, you can send the power to the inverter transfer switch after it has passed through a main breaker. You won't need another main breaker in the sub panel, so it doesn't have to be very sophisticated. A simple breaker box is sufficient.

[ernieh]

Originally Posted by unyalli

So let's explore this sub panel topic. The only one I've found so far is the 30 amp 5000 series by progressive dynamics the guys that make my PD9245C. I might be able to mount this in the wall right next to or above the existing panel for a factory look and hopefully the wiring will reach. Is there a smaller panel out there with AC only?

Actually you have more choices. My motorhome has a breaker panel that does exactly what you need. It has main buss bars for the high loads (AC, washer, dryer, block heater, etc.) and a sub panel for the inverter supplied items. I don't know the brand offhand, but will check it out. The panel is probably no larger than what you have now.

[unyalli]

I went down to the RV show in Denver yesterday and looked at a number of class A's with inverters. They had an all AC distribution panel like ErnieH is talking about and a separate DC panel with push to reset circuit breakers. The AC panel had Inverter L1 and L2 in breakers and then Inverter L1 and L2 out breakers. I could not tell what was on Inverter power though. There was no clearly defined shore and inverter sections it was 15 or so breakers in a row. I tried to tell what brand panel it was and couldn't.

[Old Bounder]

Originally Posted by unyalli

I went down to the RV show in Denver yesterday and looked at a number of class A's with inverters. They had an all AC distribution panel like ErnieH is talking about and a separate DC panel with push to reset circuit breakers. The AC panel had Inverter L1 and L2 in breakers and then Inverter L1 and L2 out breakers. I could not tell what was on Inverter power though. There was no clearly defined shore and inverter sections it was 15 or so breakers in a row. I tried to tell what brand panel it was and couldn't.

I suspect the inverter was actually a Magnum Dual input/output inverter/charger. That's a nice piece of gear.