MPP LV6548 Ground/Neutral Safety?

[timselectric]

I could go with two of the growatt 3000TL models and run in parallel to get split phase but im trying to keep things simple

Simple is best.

 

[MT off grid]

Simple is best.

I'm not sure what to do now, just when I think I have it figured out I find out I don't have anything figured out, never thought it would be so hard to just run a few critical loads off of a back up power supply

 

[timselectric]

You have to work with what you have existing.
Or, make a lot of modifications.

 

[MT off grid]

You have to work with what you have existing.
Or, make a lot of modifications.

I'm trying to work with what I have but unfortunately I don't think I have anything to work with

 

[MT off grid]

You have to work with what you have existing.
Or, make a lot of modifications.

If I went with two of the growatt 3000TL wired in parralel I could have two phase, how would that work with the two multiwire branch circuits I have? Could I just do the cord set like you were explaining earlier

 

[timselectric]

If I went with two of the growatt 3000TL wired in parralel I could have two phase, how would that work with the two multiwire branch circuits I have? Could I just do the cord set like you were explaining earlier

Yes

 

[MT off grid]

Yes

So stay split phase with two units and make my own manual transfer switch/plug, would i be able to wire it so it only runs my 120 circuits or would it need to run 120 and 240 circuits, those multiwire branch circuits have me paranoid now, I think the growatt 3000TL have a bonded neutral that can be broken by removing a ground screw, if I remove that screw i shouldn't have any problems?

 

[timselectric]

You will feed 120/240 split-phase, to the bottom bus.

 

[MT off grid]

You will feed 120/240 split-phase, to the bottom bus.

Okay, so im right back to where I was before the discovery of the multiwire branch? What happens if an inverter fails would that cause an over current issue with the multiwire branch circuits and fry electronics plugged in

 

[timselectric]

You would lose one side of the split-phase system.
Half of the panel would be dead. No other problem.

 

[MT off grid]

You would lose one side of the split-phase system.
Half of the panel would be dead. No other problem.

Oh right, sorry, the Mike holt video i watch was talking about someone accidentally removing a neutral wire which would cause an over current issue and burn up electronics, so on my two circuits that are multiwire branch if I turned one breaker off I wouldn't cause a problem? Mime holt said the two breakers should be connected so they both turn off at the same time, dose that go back to of someone doesn't know what they are doing and they only flip one breaker off and remove the neutral you burn stuff up? Sorry for the rambling, just typing as things pop in my head

 

[timselectric]

dose that go back to of someone doesn't know what they are doing and they only flip one breaker off and remove the neutral you burn stuff up?

Yes

 

[MT off grid]

Yes

So two growatt 3000TL it is, now to call an electrician to see if he wants to help, thank you for all of your help

 

[BuffaloTrace]

You already have 3 different panels. Just add another 120 volt only panel next to the most convenient, and make that a dedicated inverter panel.

 

[koppted]

Wire the breaker, to a receptacle.
Wire the bottom bus, to a reverse service receptacle.
Make a short cord to plug into both receptacles. (manual bypass)
Add input and output cords to the inverter.
They can be plugged into these receptacles. (Inverter power)
Or, a generator can be plugged into the reverse service receptacle, to feed the bottom bus. (Generator power)

Hello don't mean to get off topic. Could you explain the idea of "reverse service"? I've noticed that some wiring devices on hubbell's website says reverse service on some of their pin and sleeve connectors, never understood what it meant.

 

[timselectric]

Hello don't mean to get off topic. Could you explain the idea of "reverse service"? I've noticed that some wiring devices on hubbell's website says reverse service on some of their pin and sleeve connectors, never understood what it meant.

Standard receptacles are for outputting power.
You plug into them, to get power.
Reverse service is the opposite.
You plug in to it to give power.
They are for inputting power.
Like from a generator.

 

[timselectric]

Hello don't mean to get off topic. Could you explain the idea of "reverse service"? I've noticed that some wiring devices on hubbell's website says reverse service on some of their pin and sleeve connectors, never understood what it meant.

 

[MT off grid]

Yes

Just got this email response from MPP solar



No, there's no problem with "bonded neutral" as the way our LV6548 (or other inverters) handle N-G is as follows:

• line mode (AC bypass): output N-G open (unbonded)
• inverter mode (battery or solar): output N-G short (bonded)

This is in compliance with UL and GFCI safety standard. If neutral-ground is not bonded under inverter mode, then you'll trip RCD which tests for residual / leakage current.
I'm aware there's some recent discussion on the Web about whether you need to bond output neutral to ground -- generally the answer is no, because our inverters manage this automatically already so you don't have to do it separately.

Hope this helps.

 

[timselectric]

Just got this email response from MPP solar



No, there's no problem with "bonded neutral" as the way our LV6548 (or other inverters) handle N-G is as follows:

• line mode (AC bypass): output N-G open (unbonded)
• inverter mode (battery or solar): output N-G short (bonded)

This is in compliance with UL and GFCI safety standard. If neutral-ground is not bonded under inverter mode, then you'll trip RCD which tests for residual / leakage current.
I'm aware there's some recent discussion on the Web about whether you need to bond output neutral to ground -- generally the answer is no, because our inverters manage this automatically already so you don't have to do it separately.

Hope this helps.

Yes
This is how all inverters are supposed to work.
The issue becomes a problem, when using multiple inverters in parallel.

 

[MT off grid]

You already have 3 different panels. Just add another 120 volt only panel next to the most convenient, and make that a dedicated inverter panel.

That was my original plan, add solar subpanel, move all 120 circuits to that panel, add 100 amp transfer switch, quote was $2600.00, out of my budget