RV Inverter fail! Please help.

[Brian Boyd]

So, I am not an electrical engineer or an electrician. I have been in home remodeling business for 30 years so I thought I would be capable of a DIY solar power project on my 29 YO Diesel Pusher.
RV world originally with Heart 20D inverter on an inverter loop. Incoming shore power would go to the 100 amp split panel with one circuit getting per from inverter in an "inverter loop". This would power basics plus a microwave directly off one side of inverter.
MY plan: to wire the whole panel from a split phase 5000 watt 24v inverter, to have a 10000 watt battery bank consisting of 8 Lifepo4 100ah 12v batteries wired in series and parallel. I used a 60 amp LiTime MPPT with 6 250 watt Renogy type N panels. Panels in series and parallel 2+2+2.
My system worked great with solar power only and Ran 2 rooftop AC with no problem. Shunt keeping score. However when I plugged into shore power I got smoke and a failure code from the inverter.
Lots to unpack in finding this problem

1. shore power was a 50 amp Nema 1450 R
2. Shore power had a 50 to 30 dog one followed by an inline tester/supressor. Lights on device indicate normal.
3. 25' RV cord with another adapter back to 50 amp gen type plug on rv.
4. Power in goes through auto switch with generator power leads. Generator leads have a go between wire original from manufacturer so not true 240.
5. New 240v inverter input has Ground+Hot+Hot.
Output Has Neutral plus hot plus hot. Case has a ground. Pics below.
6. I have not plugged in with 50/50 cord. Only the 30.
7. Inverter company engineer says failure related to "angle of phase".
8. Bypassed inverter and used RV on shore power.

Trying to not burn up another inverter. I have no 240 devices to power.

 

[Brian Boyd]

Also, input neutral is wire together with output Neutral since no place for neutral on input side. All grounds wired together.

 

[Brian Boyd]

I split input terminal for neutral on output so I pulled it on the inside and connected the neutral with a but splice, marking with white vinyl tape and covering splice with 2 layers of adhesive heat shrink.

 

[zanydroid]

It’s not safe to plug a 50 to 30 120V dogleg into a split phase inverter. The support engineer’s assessment is basically saying the same thing. To be honest given that you’re missing a few critical concepts in how these systems work (and these systems are not plug and play), I think you need to pay someone to install or pay someone/make friends with someone who does a lot of EV systems to remotely selecting equipment for you / supervising your install.

Possible solutions (I can think of ways for each of these to blow up, so don’t just go blindly trying them).
- find an inverter that explicitly supports the mode you have in mind. I believe Multiplus 2x120 would be promising
- use 120V inverters

I don’t really have the time to explain beyond this (in part bc it involves a lot of coaching and tutoring over time, in part because I don’t know RV wiring), maybe you can add this when pinging others.

 

[zanydroid]

That inverter looks cursed from the start just from how it has inputs labeled L/L/G. That implies to me it requires extra hardware outside to handle switching of shore to inverter power

 

[jberger]

Why do you think you need 240v?
I doubt anything in your coach actually uses it, I think you are confusing the generator's output of (2) 120v legs as 240v.

You need to keep the transfer switch in place or wire a new one as that is where the N/G bonding needs to take place and be able to switch between Shore, Generator, Inverter. Screwing up this bonding can kill you, so get it right.

As mentioned above, look at the Multiplus ii as your inverter solution, it will greatly simplify the wiring, but you will need to reconfigure your battery into either 12v or 48v to support the current models.

 

[Brian Boyd]

Why do you think you need 240v?
I doubt anything in your coach actually uses it, I think you are confusing the generator's output of (2) 120v legs as 240v.

You need to keep the transfer switch in place or wire a new one as that is where the N/G bonding needs to take place and be able to switch between Shore, Generator, Inverter. Screwing up this bonding can kill you, so get it right.

As mentioned above, look at the Multiplus ii as your inverter solution, it will greatly simplify the wiring, but you will need to reconfigure your battery into either 12v or 48v to support the current models.

I have already v set up batteries for 24 volt and put in a 24/12 stepdown. I have nothing to that requires split phase. I do want to be able to use 50 amp shore power but only need one side. If I make the panel into single phase I will need to use only one side of the split phase input. Right now I have a separate auto transfer/ phase selector. While my 6500 watt Marquis propane Gen has two leads it has to be single phase as they are hip joined along the way.
I think I am going to convert to single phase and cap one of the 50 amp inputs from shore or just eliminate the l2 wire from inlet plug.

 

[Brian Boyd]

That inverter looks cursed from the start just from how it has inputs labeled L/L/G. That implies to me it requires extra hardware outside to handle switching of shore to inverter power

That is correct. I have a separate auto transfer switch.

 

[RvNaut]

Nothing in your rig uses 240v. The 240v unit you chose is wrong for the job... I'm not going to even try to address the wiring... I did what you are trying to do. I installed an All-In-One 120v system....

Thread 'The Build - 48 volt 280Ah - RV Integration'

Aug 18, 2022

Good Day Arm Chair Electricians
I live in a 2004 Safari Trek 31SBD. It currently has no solar, a 12 battery bank made up of 4 6-volt golf cart batts ( buh bye none too soon) and Freedom 451 Inverter charge controller( also soon to go buh bye). My power needs are vaaaahst :D I run a full size desktop computer and home stereo, recording gear etc etc... and then I intend to add a mini-split... ditching the existing AC and Heat systems. maybe run fridge a hot water on solar... I suck and intend to suck a lot of electrons.

The battery is a 16s 280Ah 48-volt setup using an Overkill 16s 100...

• RvNaut
• Replies: 19
• Forum: Vehicle Mounted Systems

 

[Mattb4]

It would help if you gave make and model of inverter.

Also, input neutral is wire together with output Neutral since no place for neutral on input side. All grounds wired together.

I would guess this is the issue. Incoming neutral might need to be isolated (not connected to anything) since the secondary side of the inverters transformer is providing it. By connecting the output neutral you are shorting the transformer if I am not mistaken.

 

[solar8484]

Assuming the 30A dog bone you used to tap the shore power is a TT30 (3 prong), you connected 120V AC to the 240V only AC input and shorted (Hot to Neutral) the inverter. Guaranteed to blow up every time. The hot legs on the NEMA 14-50 shore power connector should provide the 240V AC needed by the inverter.

 

[time2roll]

I assume the 50-30 adapter or the neutral pass through was the issue. Wiring manual should explain this.

If you want to stay with same, only use tested 50 amp power.
Get a separate battery charger to use a 30 amp 120v connection. Inverter will provide AC power from battery as needed.

 

[Brian Boyd]

e inverter. Guaranteed to

u want to stay with same, only use tested 50 amp power.
Get a separate battery charger to use a 30 amp 120

ovide AC power from bat

ral is wire together with output Neutral sinc

rong for the job

Nothing in your rig uses 240v. The 240v unit you chose is wrong for the job... I'm not going to even try to address the wiring... I did what you are trying to do. I installed an All-In-One 120v system....

Thread 'The Build - 48 volt 280Ah - RV Integration'

Aug 18, 2022

Good Day Arm Chair Electricians
I live in a 2004 Safari Trek 31SBD. It currently has no solar, a 12 battery bank made up of 4 6-volt golf cart batts ( buh bye none too soon) and Freedom 451 Inverter charge controller( also soon to go buh bye). My power needs are vaaaahst :D I run a full size desktop computer and home stereo, recording gear etc etc... and then I intend to add a mini-split... ditching the existing AC and Heat systems. maybe run fridge a hot water on solar... I suck and intend to suck a lot of electrons.

The battery is a 16s 280Ah 48-volt setup using an Overkill 16s 100...

• RvNaut
• Replies: 19
• Forum: Vehicle Mounted Systems

Only because I have a split panel and the inverter I replaced is split phase. I am considering just going single phase, capping off one side of 50 amp input, and wiring the two sides of the panel together. I can lable for the future.

 

[dopeassjackson]

That inverter looks cursed from the start just from how it has inputs labeled L/L/G. That implies to me it requires extra hardware outside to handle switching of shore to inverter power

When dealing with 240v things its prety typical for it not to matter what side of the 120v leg goes where.

It sounds like you put 120v to a 240v appliance?

 

[time2roll]

1. shore power was a 50 amp Nema 1450 R
2. Shore power had a 50 to 30 dog bone followed by an inline tester/supressor. Lights on device indicate normal.
3. 25' RV cord with another adapter back to 50 amp gen type plug on rv.


Trying to not burn up another inverter. I have no 240 devices to power.

Also get a 50 amp extension if needed. When using 50a supply and have a 50 amp RV there should be no step down to 30 amps. In effect that cord is the fuse and will melt. Always use the 30 amp pedestal connector if using a 30 amp cord.

From the pedestal or through the adapter the 30 amp is 120v 30 amps.

The 30 to 50 adapter connects the single 30A hot to both the hots going into the RV.