connecting inverter with bonded neutral to panel with same ?

ashenashashenash Registered Users Posts: 7
Hi all, I'm a long-term reader and a first-time poster to this excellent board. I knew I could get good answers here.

I have a Wagan Proline (5000 watt 120 volt 42 amp) inverter on my offgrid solar w/batteries system. I would like to connect via an interlock or manual transfer switch to my house breaker panel (GE Gold Load Center 100amp 20 circuit) I only want to power 120v loads (no 240v) I realize I'll need to move all the 120v breakers I want to power to the right side of the panel.

Yes I know not to backfeed the grid by cutting the utility off before connecting to the inverter, that's what the interlock is for.

The inverter has hardwire connections for house distributed wiring and the manual states "neutral bonded to ground internally per code"
The house main panel has neutral bonded to ground per code.

Knowing that there should only be one place where the neutral and ground are bonded, I was stumped.

So I called Wagan and the lead tech told me "no problem just connect like this"
1. Wire the inverter neutral straight thru/no breaker to the panel neutral
2. Wire the inverter ground straight thru/no breaker to the panel ground
3. Wire the inverter hot to a 50 amp breaker in the panel
4 Ground to earth the inverter chassis (house panel has water pipe ground)
5 For the 20' run use 8/2 with ground romex or marine grade

When I asked about the multiple neutral/ ground bonds he said "No problem,just wire it like I said, since the 120v inverter does not "technically" have a neutral"

So, does all this add up to good advice ? Just wire into the panel , breaking only the hot wire ? And grounding the inverter chassis to earth ?


Other folks have said that the only way to safely connect my inverter to my house wiring is to use a transfer switch that breaks the neutral.
But there seems to be no real concensus about this

I want to believe the Wagan guy, he seems very knowledgeable . Just want to make sure I asked the right questions.


Yes my solar/battery/inverter is sufficient for the loads I want to power. I've been using it with extension cords

I am ready to lose the extension cords and get this inverter wired up to my panel. I can handle the connections safely (at least with the interlock kit scenario) but I will use a pro if it gets more complicated (transfer switch)

Thanks in advance for your input
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Comments

  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    Welcome to the wonderful world of code approved grounding. He is right. The neutral is your current carrying conductor for current to the ground. The Inverter ground is the EGC - equipment grounding conductor - to protect you by grounding the metallic parts of the inverter in case they happen to get energized. The third ground (#4 in your ist) is the GEC - grounding electrode conductor - is your lightning protection . If the inverter doesn't use the neutral, it doesn't have to be installed. The EGC is absolutely needed, can be one size smaller than your current carrying conductors (#10 in your case) and must be green. The GEC, if it is routed seperately from the others (outside the conduit so that it doesn't induce surge currents into the other conductors) needs to be #6 minimum usually solid CU and should go directly to the ground rod if possible. The alternative is to combine the GEC and EGC together into one wire inside the conduit, but has to be #8 minimum, green, and has to be bonded (bond bushings) to both ends of the conduit instead of just one as the conduit acts as an inductive choke during current surges (lightning) and bonding both ends reduces its impedance. That's the theory anyway. If your inverter is close to the ground rod, run the GEC separetely - if far away, easier to combine it with the EGC.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    He is wrong. With two N-G bonds you have a ground loop which can cause problems. One or the other must be removed.

    With two in place the ground wire between the breaker panel and inverter can carry current while in normal operation. Ground wires should not carry current unless there is a fault. It all has to do with the amount of resistance in each line and how that affects current flow.

    Electrical safety ground has nothing whatsoever to do with lightning protection. That is a completely different can of worms.

    That 5kW inverter - what is the DC Voltage? Please tell me it is 48 and not 12.
  • BB.BB. Super Moderators, Administrators Posts: 29,849 admin
    Re: connecting inverter with bonded neutral to panel with same ?

    If you wire the Green wire ground and the White Neutral directly to your home's main panel--You will usually see that the Green Wire bus bar and the White neutral bus bar are exactly the same bus bar, or the two are directly connected together electrically via a jumper wire or grounding screw. So, connecting the two Green and White wires to the same bus is OK... Personally, I would keep the two G&W wire the same AWG size... Since they are in parallel, you will have operating AC current flowing through both of them and there is no way to know (ahead of time) if they are going the "split" the current flow in 1/2 or if one or the other wire will be carrying 100% of the AC neutral current (since both wires are connected in parallel with unknown common connections at both ends).

    The Transfer Switch Step #3 (black wire to 50 amp breaker in panel)... While technically, you can connect the inverter that way to your loads--You end up with two issues.

    First, the you have to make sure that either the main house breaker is off whenever the 50 amp breaker is on--And that the 50 amp breaker is off whenever the main house breaker to the utility grid breaker is on. While it seems simple enough--It is not safe and it is not legal. It is two easy to to make a mistake (no interlock between the 50 amp and Main utility breaker. If both breakers are no--You either kill the AC inverter if the utility is working... Or you energize the utility lines if the utility power is down (and possibly kill somebody or a lineman if the AC lines are down).

    There are manual transfer switches that allow you to wire up individual circuits in your home to your backup power supply (inverter or generator). Here is an example of a manual, multiple circuit retrofit AC transfer switch product line (I know nothing about the products or the companies):

    http://www.reliancecontrols.com/q-series-pro-tran.aspx

    Your second issue with #3... There are two bus bars in your main panel... Line A and Line B (assuming you have standard North American 120/240 VAC split phase power). With a single 50 amp breaker, only 1/2 of your home's circuits will get AC power--The other 1/2 will still be dead (you are only powering one of two bus bars).

    If you power both Line A and Line B with your 5,000 watt AC inverter (even with the manual AC transfer switch I linked to), there is another issue.

    It depends on how your home is wired. With 120/240 VAC split phase power. It is legal and common that a pair of Black+Read (line A and line B) share a common neutral (example would be a 3 conductor Romex+Ground wired out to a kitchen). A shared white/neutral wire will never carry more current than the single 120 VAC line breaker rating (because A and B lines are 180 degrees out of phase, their total current subtracts from each other). If you jumper A+B so you can power all of your home's loads, if there is a shared neutral to some of your 120/240 VAC circuits, the shared neutral will now have up to 2x rated current flowing through it (A&B are now the same phase -- I.e., A+A line current). So--You have to identify and shared AC Neutrals and never supply them with A+A power or rewire with a separate neutral to each load.

    This can be all done (I did this with a very similar manual transfer switch and made sure that the circuits I powered in my home did not share a common neutral when I connected my panel to a 120 VAC only backup generator).

    I am nervous about what you are doing.

    I don't like 5,000 watt 12 VDC inverters (5,000 watts on a 12 volt battery bus can carry 560 amps (or 2x that during starting loads)... That is a lot of current at 12 volts (or any voltage).

    And I still wonder if the MSW Wagon Inverter has AC output to DC input galvanic isolation--The manual is pretty clear that this MSW inverter has an isolated AC output. Most MSW inverters cannot be connected as listed below without shorting out the AC inverter...

    If I have the correct manual:

    http://www.wagan.com/media/pdf/manuals/2012.pdf
    HIGH OUTPUT AC TERMINALS
    There are three insulated terminals on the front panel of the inverter. These terminals
    are for connecting 11 5 volt AC devices that require more than 1 5 amps to operate.
    Other uses are for connection to distributed wiring that has multiple AC outlets. Any
    wiring that is directly connected must be 10 gage or larger. Facing the front panel,
    the terminals are:

    Left / Middle / Right
    Earth (Ground) / Neutral / Live (Hot)

    NEUTRAL and EARTH are bonded inside the inverter to comply with the National
    Electric Code (NEC) requirement that any AC source must have a neutral to ground
    connection.
    GROUND TERMINAL [Chassis Ground Terminal]
    This terminal is for attaching a 6 gauge insulated safety ground wire. This safety
    wire protects personnel if there is an unlikely failure in either the cabling or
    enclosure insulation. Do not directly connect this ground to any negative DC terminal
    on the inverter. This safety wire is to be connected to the vehicle frame or earth
    ground or negative battery terminal as described in the installation procedure.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    #2 and #4 together would violate code for single ground bond strap of neutral at service entrance.

    Question is whether the inverter boost circuitry is totally isolated from HV DC and AC secondary side of inverter. If it is you should also be able to ground to inverter case to the negative terminal of battery while neutral side of AC out is grounded to inverter case. This is to ensure the battery terminals do not have 120vac relative to ground which would be a safety hazard.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    Bill; If I read it right he says the inverter has a built-in N-G bond, as such it should be pure sine.

    It can't be done the way it's described, that's for sure. it would not be safe for ground, disconnect, or powering 240 loads if the breaker allocation doesn't work out right.

    Not sure it is a 12 Volt 5kW inverter either. If it is, I'd toss it in the trash where it belongs and get a good unit instead.
  • BB.BB. Super Moderators, Administrators Posts: 29,849 admin
    Re: connecting inverter with bonded neutral to panel with same ?

    The manual I found (based on his description) says it is a 12 volt MSW type inverter (grounding quotes from that manual)...

    There are a few MSW inverters that have AC to DC isolation (I believe that Magnum has some Isolated MSW inverters).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    Not sure it is a 12 Volt 5kW inverter either. If it is, I'd toss it in the trash where it belongs and get a good unit instead.

    'coot - ever heard the old phrase "you ain't seen nuthin' yet"?

    Check out the 10,000 watt 12V inverter:
    http://www.wagan.com/index.php/products/power-inverters/off-grid-home-inverters/2483-10-000-watt-continuous-power.html

    Let's see, 10,000 watts is like 90 amps @ 110V. Right? On one single phase wire? And on the DC side, at 90% optimal efficiency ~11,000 watts @ 12VDC is 917 amps. Right? From WHAT? And be able to maintain 12V at the inverter studs?

    ROTFLMAO! Sorry. Couldn't help it :cry:
    --
    Chris
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ChrisOlson wrote: »
    Let's see, 10,000 watts is like 90 amps @ 110V. Right? On one single phase wire? And on the DC side, at 90% optimal efficiency ~11,000 watts @ 12VDC is 917 amps. Right? From WHAT? And be able to maintain 12V at the inverter studs?

    Don't forget about 20,000W peak rating!
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?
    NorthGuy wrote: »
    Don't forget about 20,000W peak rating!

    Where do you guys get these fantastic numbers ?

    It is a 5k (continuous) inverter with 10k peak if I tie into my household load center it will be through a 60 amp breaker, so 60 amps max into the panel

    The battery bank is on 2-250 amp breakers which trip reliably when tested, in over a year of regular use they have never tripped under my normal loads

    The bank also has 2-500amp backup fuses in the unlikely event that the breakers fail to trip
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?
    Not sure it is a 12 Volt 5kW inverter either. If it is, I'd toss it in the trash where it belongs and get a good unit instead.

    While I am sure that 24 or 48 volt inverters have their advantages this 12v unit has performed reliably and is adequate for my current needs

    Your snarky comments are not helpful.

    Thanks to all who have offered useful info.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    While I am sure that 24 or 48 volt inverters have their advantages this 12v unit has performed reliably and is adequate for my current needs

    Your snarky comments are not helpful.

    Thanks to all who have offered useful info.

    My comments are not snarky, they are technically accurate: to draw the actual full Wattage rating of the inverter from 12 Volts would require more than 400 Amps of current. It is not possible to draw that much current through a single standard wire (such as 4/0) so parallel conductors are required to meet the maximum power. Such wiring is problematic, to say the least. Furthermore you would need a tremendous Amp hour battery bank to survive such a demand.

    Therefor we see this is a badly designed inverter. The 5kW rating is stuck on it to sucker people into thinking it is superior to 12 Volt inverters that produce "only" 2kW. This is not honest marketing. Most people will never load their inverters to this point, and so the maker gets away with it.

    I am even more sure than you that 24 and 48 Volt inverters have their advantages because I understand what I'm talking about. Ignore my advice at your own peril.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ChrisOlson wrote: »
    'coot - ever heard the old phrase "you ain't seen nuthin' yet"?

    Check out the 10,000 watt 12V inverter:
    http://www.wagan.com/index.php/products/power-inverters/off-grid-home-inverters/2483-10-000-watt-continuous-power.html

    Let's see, 10,000 watts is like 90 amps @ 110V. Right? On one single phase wire? And on the DC side, at 90% optimal efficiency ~11,000 watts @ 12VDC is 917 amps. Right? From WHAT? And be able to maintain 12V at the inverter studs?

    ROTFLMAO! Sorry. Couldn't help it :cry:
    --
    Chris

    Yes, AIMS makes a piece of junk like this too. They rely on four parallel conductors to supply the current. Even then 4/0 would be pressed at maximum power. The battery bank required to support that would be a nightmare. And you don't get enough scrap value from the case to make it worthwhile hauling in to the recycler.

    It's bad marketing hype is all it is.
  • islandguyislandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    @ashenash
    I am using something similar, a 6k MSW that will surge to 12K. While it has been pointed out that my set-up is probably not the best way to go about it, in general the comments here have been very helpful and I've certainly learned a great deal here.

    A couple of things to suggest; At the top of your mains panel, placing a jumper between the two 110v legs will allow you to use both sides of your panel.

    In my case, to get around the limitations of a MSW inverter I also purchased a smaller PSW. This inverter is dedicated to circuits for computers, AV setup and power tool battery chargers.

    In working with a budget I purposely chose the 6K MSW for a number of reasons. Size, price, 50 amp charger and the belief that it would be somewhat abuse proof. Even with what I have learned here I probably would have started out with that unit.

    Something that BB linked to: http://www.screenlightandgrip.com/html/emailnewsletter_generators_ext.html excellent read on generator output and equally applicable to inverters in my opinion. Depending on your usage it might make you rethink the importance of a PSW inverter.
  • solar_davesolar_dave Solar Expert Posts: 2,347 ✭✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    Where do you guys get these fantastic numbers ?

    It is a 5k (continuous) inverter with 10k peak if I tie into my household load center it will be through a 60 amp breaker, so 60 amps max into the panel

    The battery bank is on 2-250 amp breakers which trip reliably when tested, in over a year of regular use they have never tripped under my normal loads

    The bank also has 2-500amp backup fuses in the unlikely event that the breakers fail to trip

    They are talking about a different one from the same manufacuter:
    http://www.wagan.com/index.php/products/power-inverters/off-grid-home-inverters/2483-10-000-watt-continuous-power.html

    and the point is even a 5000/10000 surge is huge on a 12 V system! That is a max of 833 amps @ 12 V. How you going to past that much amperage? What gauge wire is required?

    BTW 10,000 watts @ 120V is 83 amps.
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    islandguy wrote: »
    A couple of things to suggest; At the top of your mains panel, placing a jumper between the two 110v legs will allow you to use both sides of your panel.

    May not be such a good idea if the panel is connected to some 240V source.

    Before you do anything, could you please tell us why do you need to connect it to a panel and why do you use "interlock". Is this panel connected to something else? I understand that this cannot be grid because the system is off-grid. But it has to be connected to somethig because otherwise you would wire directly to the panel, right?
  • islandguyislandguy Solar Expert Posts: 80 ✭✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    @Northguy
    Good point! I was thinking it was all off grid all 110v loads.

    Thanks.
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    That Wagan inverter is not even UL Listed. It is illegal to hook it to a grid service entrance in the US. The neutral/ground bonding is minor compared to the compliance issue for any device hooked to a grid service.
    --
    Chris
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?
    solar_dave wrote: »
    They are talking about a different one from the same manufacuter:
    http://www.wagan.com/index.php/products/power-inverters/off-grid-home-inverters/2483-10-000-watt-continuous-power.html\


    and the point is even a 5000/10000 surge is huge on a 12 V system! That is a max of 833 amps @ 12 V. How you going to past that much amperage? What gauge wire is required?

    BTW 10,000 watts @ 120V is 83 amps.

    Had they read the op they would have seen: I have a Wagan Proline (5000 watt 120 volt 42 amp) inverter on my offgrid solar w/batteries system. I would like to connect via an interlock or manual transfer switch to my house breaker panel (GE Gold Load Center 100amp 20 circuit) I only want to power 120v loads (no 240v)

    How do I past that much amperage ? I don't.need to. The battery bank is protected by 250 amp breakers and 500 amp backup fuses (is there an echo in here ?)

    Cabling: 1/0 is recommended, but I used 2/0 . 2 for the neg, 2 for the +

    Forgot that the inverter has overcurrent shutdown.

    AC side would be on a 60 amp breaker

    does anyone else have deja vu ?
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    Cabling: 1/0 is recommended, but I used 2/0 . 2 for the neg, 2 for the +

    They recommend 1/0 for 5,000 watts on 12V? And you used 2/0 with 250 amp breakers? This only gets worse. What code book did you pull that out of? For automotive you can run 265 amps on 2/0. But not in residential, AC or DC. 2/0 copper conductors are 175 amp max @ 75C rating.

    Anyway - you cannot hook that inverter to a grid service entrance because it is not UL1741 compliant. Period.

    Technically, you can use a UL Listed generator transfer switch, with a switched neutral, and hook it in similar to the way a standby generator with a bonded neutral would be connected to a residential grid service. But you cannot hook the inverter's output directly to the panel in any way, shape or form. If you have shared neutrals from one side of the panel to the other, those will have to be pulled and put on the transfer switch. Being that you have an internally bonded neutral, it requires a separate driven ground rod for the off-grid system.
    --
    Chris
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    Had they read the op they would have seen: I have a Wagan Proline (5000 watt 120 volt 42 amp) inverter on my offgrid solar w/batteries system. I would like to connect via an interlock or manual transfer switch to my house breaker panel (GE Gold Load Center 100amp 20 circuit) I only want to power 120v loads (no 240v)

    We all read it and understand it. The reference to the 10kW inverter from the same company was to demonstrate the problems with inverters from that company.
    How do I past that much amperage ? I don't.need to. The battery bank is protected by 250 amp breakers and 500 amp backup fuses (is there an echo in here ?)

    Apparently there's an echo somewhere, as that is unnecessary redundant over-current protection.
    Cabling: 1/0 is recommended, but I used 2/0 . 2 for the neg, 2 for the +

    Yes; two parallel cables. Bad idea. Each needs to have its own circuit protection. 1/0 is good for 150 Amps continuous max, so duals would take 300 - which doesn't make the current expected at 5000 Watts. You are smart to use 2/0 instead which can take 200 Amps.
    Forgot that the inverter has overcurrent shutdown.

    That would be for over-current on the AC side, not the DC side.
    AC side would be on a 60 amp breaker.

    Which would be right for 5kW on 120 VAC (42 Amps), but there should be no such thing as 5kW on any single 120 VAC circuit.
    does anyone else have deja vu ?

    Yes; you wouldn't believe the number of times I've been asked to fix systems that were comprised of poor-quality components. It's all too familiar to me.

    And as Chris said; the inverter is not UL listed and legally can not be connected to your service panel.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ChrisOlson wrote: »
    They recommend 1/0 for 5,000 watts on 12V? And you used 2/0 with 250 amp breakers? This only gets worse. What code book did you pull that out of? For automotive you can run 265 amps on 2/0. But not in residential, AC or DC. 2/0 copper conductors are 175 amp max @ 75C rating.

    Not sure of this, but reading the OP's post #19, I think he used TWO 2/0's in parallel. I find that part of the code a bit confusing... I think there is some provision for doubling up cables in some circumstances.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    Had they read the op they would have seen: I have a Wagan Proline (5000 watt 120 volt 42 amp) inverter on my offgrid solar w/batteries system. I would like to connect via an interlock or manual transfer switch to my house breaker panel (GE Gold Load Center 100amp 20 circuit) I only want to power 120v loads (no 240v)

    I still don't understand. Are you off-grid or do you have a grid connection? The panel that you refer to, is it connected to grid or any other power source at the moment?
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    vtmaps wrote: »
    Not sure of this, but reading the OP's post #19, I think he used TWO 2/0's in parallel. I find that part of the code a bit confusing... I think there is some provision for doubling up cables in some circumstances.

    Parallel 2/0 conductors is fine. But you can't put a 250 amp breaker on each one. 200 amp breaker and the max continuous current rating of the wire is 175 @ 75C, per conductor.

    Will a 2/0 copper conductor carry 265 amps? Absolutely - no problem. The problem is in wiring residential vs automotive or marine applications. For residential you can't recommend that 265 amps is OK for 2/0 cable because of NEC.
    --
    Chris
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?

    We all read it and understand it. The reference to the 10kW inverter from the same company was to demonstrate the problems with inverters from that company.

    Sorry If I misunderstood, but its seems that the references to 20k watts and 917 amps are not pertinent to my inverter or this discussion

    Apparently there's an echo somewhere, as that is unnecessary redundant over-current protection.

    So too much safety is a bad thing ? (The 500 amp anl fuses were already in line on the cables, using them I was able to repurpose materials and add another failsafe)


    Yes; two parallel cables. Bad idea. Each needs to have its own circuit protection. 1/0 is good for 150 Amps continuous max, so duals would take 300 - which doesn't make the current expected at 5000 Watts. You are smart to use 2/0 instead which can take 200 Amps.

    Each has its own circuit protection times 2. And you think I'm smart !

    That would be for over-current on the AC side, not the DC side.

    And when the inverter shuts down the battery circuit is broken


    Which would be right for 5kW on 120 VAC (42 Amps), but there should be no such thing as 5kW on any single 120 VAC circuit.

    Never said I need or use 5kW, 3500 max and even less would be possible with my current breakers.


    Yes; you wouldn't believe the number of times I've been asked to fix systems that were comprised of poor-quality components. It's all too familiar to me.

    The echo in here and the deja vu are from me having to repeat the specs multiple times. I never asked you to "fix my system" It works fine as is. I came here to get input about connecting my current working system to my panel. Several posters offered good input, some even offered solutions.

    Throwing a working inverter in the trash is not a solution. If all you can do is denigrate my system then you may consider yourself "unasked" and make way for creative input.

    And as Chris said; the inverter is not UL listed and legally can not be connected to your service panel.


    Ah, there's the rub. It can be done safely, but not legally. I will consider this, and remain aware that what is safe is not always legal and vice versa

    I respect you opinion. After all, you are a moderator on a discussion board on the internet.

    So, have the last word, as I fully expect you will.

    I need a good laugh.
  • solar_davesolar_dave Solar Expert Posts: 2,347 ✭✭✭✭
    Re: connecting inverter with bonded neutral to panel with same ?

    What I don't understand is why you would use 12V for this when 48V would simplify your wire requirements so much? And probably provide a safer solution.
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?
    NorthGuy wrote: »
    I still don't understand. Are you off-grid or do you have a grid connection? The panel that you refer to, is it connected to grid or any other power source at the moment?

    I should have said "off-grid w/batteries backup for blackouts or alt power when I don't want to burn coal"

    I am still on the Progress-Duke teat, unfortunately.

    I dream of being totally self-sufficient for electricity but realize as a DIYer that it takes baby steps. I also realize that amps kill with no apology. So I ask a lot of questions, formulate a design, and when it is over my head I have it reviewed by my master electrician friend and installed by my journeyman buddy.

    And I still get a chuckle when I see a pricey sell-all that fails to provide any juice during a blackout.

    Thanks for your interest.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    solar_dave wrote: »
    What I don't understand is why you would use 12V for this when 48V would simplify your wire requirements so much? And probably provide a safer solution.

    Because he is not an engineer and does not understand the consequences of the high current situation.
  • ashenashashenash Registered Users Posts: 7
    Re: connecting inverter with bonded neutral to panel with same ?

    simple economics
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    I am still on the Progress-Duke teat, unfortunately.

    The MSW inverter that you have produces a square wave, instead of sine wave, while all the appliances are designed for sine way. Something may burn down. Sort of like a lottery.

    So you want to switch between solar and grid and you bought a manual transfer switch for that.

    There are two ways you can connect your inverter.

    1. You connect it for the whole house, so you whole house gets switched. It's either or.

    2. You create a subpanel and you move part of your loads into this subpanel. Then loads that you moved get switched. The rest sits on the grid.

    These are wastly different, so you need to chose one of these.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: connecting inverter with bonded neutral to panel with same ?
    ashenash wrote: »
    simple economics

    Nope.
    Engineering.
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