Hello, 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?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?JeffP.S. I will never try to draw a continuous 3000 or even 2000 watts from my batteries.Moderator edit to re-size pictures to forum limit of 640px maximum width.

Of course what you have described is the so called easy part of your install.I think your 3000WATT INVERTER will need around 250AMPS DC Current to operate it at full load which has to come from your battery bank. I notice the spec sheet calls for a 400AMPS DC source to be used. This is some serious capacity requirement.You will need to install several batteries in your battery bank to handle this very large load even for just a few hours. Also when you increase your battery bank capacity then you also have to increase your ON-BOARD Charging system to be able to recharge the battery bank in the desired time you want to the battery bank to return back to a usable charge state.Alot of planning will be required in this area as well. The only real time example I can offer from experience is I had to load down a 1500WATT Inverter with test equipment on one Antenna field repair test we were involved with back in my working days. All we had was a rental car with it's single probably a 105AH battery in it. We fired up all of the test equipment was wanting to use which just barely added up to a full load of 1500WATTs. They all fired up normal but only lasted about 15 minutes before running the rental car battery down to a full discharge.1500WATTS operated by a 12.3VDC source would represent around a 120AMP DC LOAD (not counting losses). 120AMPS is half the current load of the 3000WATT Inverter so this would drain the 105AH battery in about 7 minutes all things being equal. If you are wanting to run your trailer setup for 8-10 hours like most of us want to do you are going to need many 12VDC batteries in your battery bank... The manufacture wants you to install a 400ADC battery source which will include larger battery cables and a much larger setup to give you a more reliable system to use. Just passing along to make sure you are understanding what you may be up against for the 3000WATT INVERTER install.Roy Ken

Jeff,Interesting problem - I guess Magnum wants you to buy two inverters to run a 50a trailer huh? What a PITA!I put a separate incoming power panel in a cabinet above my house panel, which feeds the Magnum. Originally I thought I would move my AC and Fridge to it, but decided not to hassle with it. I wanted to be able to run the AC in a pinch if things got really hot.

RoyB wrote:You will need to install several batteries in your battery bank to handle this very large load even for just a few hours. Also when you increase your battery bank capacity then you also have to increase your ON-BOARD Charging system to be able to recharge the battery bank in the desired time you want to the battery bank to return back to a usable charge state.Jeff, I missed that part, is this install going in a motorhome, so an extra alternator or bigger alternator is required?The Magnum has a 125 amp 4-stage charger, but that only works on shore power, not driving down the road :)

GordonThree wrote:Jeff, Interesting problem - I guess Magnum wants you to buy two inverters to run a 50a trailer huh? What a PITA!Only if you want both legs. I don't. I bought this rig because it was the only fifth wheel toy hauler out there within my weight restrictions. The two major draw backs with this rig are the 50 amp service and that asinine cougar touch panel. We can never have everything we want.GordonThree wrote:I wanted to be able to run the AC in a pinch if things got really hot.I live and camp out west usually above 6000ft altitude. All though we see 95 degrees it's never humid so rarely if ever NEED air cond. With this hybrid inverter and the solar IF I need AC I can provide the 1600 watts between my 1500 watt 2000i champion and the 700 watt solar array. The batteries are for the inrush surge when the compressor starts thus the 3000 watt size. In addition to all the left side breakers the AC breaker would be off all the time as well. If I turned the AC breaker on the microwave breaker would go off.JeffIn addition if I ever started to need AC more often I would replace that obnoxiously loud and inefficient 15k Dometic with a 13.5k Coleman Mach III PS (not the plus). This way I would only need 1100 watts.Moderator edit to re-size picture to forum limit of 640px maximum width.

Hi,Two of these would work to power a 50 amp RV: Outback 1300 wattTo stack units, you need the OutbackMATE (~$230) and the OutbackHUB (~$150 for the 4 port).

Magnum 3000w inverter in 50amp system | Good Sam Community

13 Replies

GordonThree
Explorer
Feb 25, 2014
RoyB wrote:

You will need to install several batteries in your battery bank to handle this very large load even for just a few hours. Also when you increase your battery bank capacity then you also have to increase your ON-BOARD Charging system to be able to recharge the battery bank in the desired time you want to the battery bank to return back to a usable charge state.

Jeff, I missed that part, is this install going in a motorhome, so an extra alternator or bigger alternator is required?

The Magnum has a 125 amp 4-stage charger, but that only works on shore power, not driving down the road :)
GordonThree
Explorer
Feb 25, 2014
Jeff,

Interesting problem - I guess Magnum wants you to buy two inverters to run a 50a trailer huh? What a PITA!

I put a separate incoming power panel in a cabinet above my house panel, which feeds the Magnum. Originally I thought I would move my AC and Fridge to it, but decided not to hassle with it. I wanted to be able to run the AC in a pinch if things got really hot.
RoyB
Explorer II
Feb 25, 2014
Of course what you have described is the so called easy part of your install.

I think your 3000WATT INVERTER will need around 250AMPS DC Current to operate it at full load which has to come from your battery bank. I notice the spec sheet calls for a 400AMPS DC source to be used. This is some serious capacity requirement.

You will need to install several batteries in your battery bank to handle this very large load even for just a few hours. Also when you increase your battery bank capacity then you also have to increase your ON-BOARD Charging system to be able to recharge the battery bank in the desired time you want to the battery bank to return back to a usable charge state.

Alot of planning will be required in this area as well. The only real time example I can offer from experience is I had to load down a 1500WATT Inverter with test equipment on one Antenna field repair test we were involved with back in my working days. All we had was a rental car with it's single probably a 105AH battery in it. We fired up all of the test equipment was wanting to use which just barely added up to a full load of 1500WATTs. They all fired up normal but only lasted about 15 minutes before running the rental car battery down to a full discharge.

1500WATTS operated by a 12.3VDC source would represent around a 120AMP DC LOAD (not counting losses). 120AMPS is half the current load of the 3000WATT Inverter so this would drain the 105AH battery in about 7 minutes all things being equal. If you are wanting to run your trailer setup for 8-10 hours like most of us want to do you are going to need many 12VDC batteries in your battery bank... The manufacture wants you to install a 400ADC battery source which will include larger battery cables and a much larger setup to give you a more reliable system to use.

Just passing along to make sure you are understanding what you may be up against for the 3000WATT INVERTER install.

Roy Ken

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Magnum 3000w inverter in 50amp system

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