Inverter and 2 way switches.. and possible issues..??

Someone replied to my post on another subject.. hence the question is raised..

They said you cannot have ANY 2-way switches on the inverter output 110-120V circuit as it may cause overload of the neutral and create a possible fire hazard.

Anyone hear of this??

I was planning on putting in a ceiling fan on the 110V AC side in my cabin and using a switch to turn it on/off from 2 different points in the cabin (front door and back room)..

Obviously my 110V AC panel would have breakers and such and all wiring done correctly per normal codes..

Is he/she referring to something else??
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Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,351 admin
    Re: Inverter and 2 way switches.. and possible issues..??

    I am not sure, but I think you are talking about connecting two (typically) TSW inverters to share a common neutral bus. (note: almost no MSW inverter's output can be connected to a grounded neutral. And most TSW inverters can. Read the manuals before making any such connections--if done with the wrong inverter a grounded AC Neutral and Common Battery Ground can smoke the inverter).

    If you are not using inverters designed for "stacking" (creating a 120/240 VAC power system where the two inverters are 180 degrees out of phase and the A+B current subtract from each other in the neutral wire current)--Then there is the possibility of the A and B inverters' currents from adding up to the total of the two inverter's 120 VAC output current instead of subtracting like a split phase system would (i.e., center tapped transformer).

    So, if you had two 15 amp output inverters connected with a common neutral, the return current in the neutral can reach 30 amps--and overheat the return "common" neutral wiring.

    If this was a stacking inverter 120/240 VAC configuration (Outback and some other 120/240 VAC inverter and generator setups), the current would add up to zero amps on the neutral.

    Is that what you where asking about?

    -Bill

    PS: If you use two different Neutral Return Wires (i.e., a separate Hot and Neutral Wire to each load, then the neutrals themselves will not overheat--However, the Neutral Bus Bar still needs to be sized for the A+B as maximum current for "unsync'ed" paralleled inverters).
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    ywhic wrote: »
    Someone replied to my post on another subject.. hence the question is raised..

    They said you cannot have ANY 2-way switches on the inverter output 110-120V circuit as it may cause overload of the neutral and create a possible fire hazard.

    Anyone hear of this??

    I was planning on putting in a ceiling fan on the 110V AC side in my cabin and using a switch to turn it on/off from 2 different points in the cabin (front door and back room)..

    Obviously my 110V AC panel would have breakers and such and all wiring done correctly per normal codes..

    Is he/she referring to something else??

    Al;

    What you are describing is actually known as a "three way switch": ON-OFF-ON - because it can switch from two locations.
    There's is no way any such switching can cause any trouble with any type of inverter output. It simply re-arranges the hot power path; nothing to do with neutral or current.

    Nor will four way switches (hard to find them these days: they go in between three-ways to create additional change points in the circuit path and add further control locations).

    I've no idea what the warning was about. Possibly what Bill said about tying output of two different inverters together, but that's not what you are after.
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    From my other thread on 1 big and 1 small inverter in the Offgrid section..
    erne wrote: »
    also remember if you have any 2 way switches on a single inverter you can overload the neutral and create a fire hazard.
    erne wrote: »
    For the two way or three way switch what happens is one switch is on one circuit while the other is on the other, thus allowing both sides to be run on a single unfused neutral. The amperage can double without tripping a breaker and the neutral can heat due to the overload of both circuits returning on a single wire.

    I just want to know if I'll be ok with 1 inverter going to a ceiling fan via the alternate (2 separate switchs) off/on switch like most house have..
  • BB.BB. Super Moderators, Administrators Posts: 29,351 admin
    Re: Inverter and 2 way switches.. and possible issues..??

    I am not quite sure I follow the Wiring--But, this is an issue where you have several loads sharing the same return neutral and two power source.

    Say you have a Washer and Freezer sharing the return path of a common neutral. And you have the washer and freezer so that they can be powered by the inverter. And you have a "Three Way Switch" wired so that you can flip the Washer to the AC Generator output instead. Now--if there is a failure (or overload) on both the Inverter/Freezer circuit and the Washer/Generator circuit, the common return currents add up on the neutral return wire.

    I think this is what is being discussed... (generator + inverter; two different inverters, etc. with common grounded neutrals).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    "For the two way or three way switch what happens is one switch is on one circuit while the other is on the other"

    :confused: What on Earth is he talking about?

    A three way switch interrupts a single wire and gives it the option of two different continuing paths. The second such switch picks up these two paths and redirects it back to the single wire, then to the load, and from the load the current returns on neutral. It is not a problem for inverters or generators or utility or battery power for that matter.

    Maybe he thinks you plan on having two separate power runs to one device, each with it's own switch? That's called "totally improper wiring procedure".

    You can Google images for three-way wiring and see how simple it is.
  • icarusicarus Solar Expert Posts: 5,156 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    Get and read a copy of "wiring simplified" and understand 3 way (and 4 way switches. There really is no such thing as a "2 way" switch, (in this context), a simple on/off switch is a "single pole/single throw switch. You could also have single pole/double throw and double pole/double throw switches, non of which are described as "2 way switches"

    A 3 way switch simply switches both on or off from two locations, a four way from 3 (or more) locations.

    Please more accurately describe you wiring situation RE: inverter. The only issue that I know about is feeding 2 circuits on different neutral busses, feeding on a three wire cable with shared neutral. In this case you could feed say 15 amps on each hot leg from separate breakers, but the neutral would be carrying 30 amps if it both hot legs were on the same buss. Putting each feed on opposite busses results in the neutrals being 180 degrees out of phase, with the net result, the neutral only "carries" 15 amps.

    Tony
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    Heres my layout as I see it happening..

    SystemLayoutDrawing.jpg

    The only thing not in the picture is the ceiling fan.

    I want to have 2 separate (location) switches to turn in on or off.. Like some houses do.. I've done it in my last house using GRID.. wiring isn't the question..

    I was questioning ernes comments that using an inverter may cause an issue with the neutral causing a fire hazard.. though I don't see how that could occur.. if that was the case my house would have burnt down..
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    ywhic wrote: »
    I was questioning ernes comments that using an inverter may cause an issue with the neutral causing a fire hazard.. though I don't see how that could occur.. if that was the case my house would have burnt down..

    You are correct; it is not possible. Single power source means there is only one power path ever available: hot to neutral.

    Even if you used two separate standard switches (don't) it could not present a problem.

    I took out some bad wiring in the old house where they'd loop a circuit back to the same leg through two breakers. Worked perfectly in operation, but the wiring wasn't protected because it had 30 Amps of breaker feeding 15 Amps of wire capacity - and you couldn't shut the circuit down until you figured out what stupid thing they'd done!
  • erneerne Solar Expert Posts: 41
    Re: Inverter and 2 way switches.. and possible issues..??

    I stand corrected on the term 2 way. Three and four way switches are designed to be used on a 220 volt system and it is against code to jumper an electrical box to use the two 110 volt lines in a single fashion. The electrical box is designed to have the two circuits 180 degrees out of phase. Any thing else in not code. The usage of both sides of a electrical box on a single inverter could nullify your insurance if a fire were to occur. I have seen these
    jumpers in use last for years without problems and I just helped extinguish a fire due to this non code violation. The house was a total loss. You make the decisions and you live with the consequences.
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    More than likely I will be using a single 2000w inverter for the entire system..

    So only a single 110V line coming thru..

    All the 3 way switch pictures I have seen do not show anything saying only for 220 VAC systems on them..

    I really don't see how a switch powering a circuit with another switch make/breaking the circuit can cause an issue..
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    erne wrote: »
    I stand corrected on the term 2 way. Three and four way switches are designed to be used on a 220 volt system and it is against code to jumper an electrical box to use the two 110 volt lines in a single fashion. The electrical box is designed to have the two circuits 180 degrees out of phase. Any thing else in not code. The usage of both sides of a electrical box on a single inverter could nullify your insurance if a fire were to occur. I have seen these
    jumpers in use last for years without problems and I just helped extinguish a fire due to this non code violation. The house was a total loss. You make the decisions and you live with the consequences.

    erne, this is not so.
    Three way and four way switches are designed to be used on 120 VAC systems to switch lights or other low current loads on and off from multiple locations. They are definitely not designed to switch 120 VAC loads between two legs of 240 VAC or two 120 VAC sources or any other such application.

    Whereas a standard 240 VAC electrical service box is designed to split 120 VAC loads between the two legs of the service, this has nothing to do with 3 way switches.

    There is really no problem with feeding both L1 and L2 from the same hot of a 120 VAC inverter. The neutral line can not be overloaded in this way, nor does it present any fire hazard as there is only one power source and the only power path is from hot to neutral, regardless of whether the hot output is split to handle two sets of breakers at the service panel.

    The source of the fire you experienced could only be due to improper wiring from the service panel to the load. Someone obviously connected a greater than 15 Amp load between two hot lines and one neutral. This mistake could be made on any type of service including a full 240 VAC system (which would also start a fire). When the two breaker bus bars are fed from one source each breaker should have its own hot and return neutral. Never should a neutral be shared. Regrettably some 240 VAC in some locales are allowed to be wired thus with the notion that the current will balance between the two hots. This is in my opinion a bad wiring practice, yet it is allowed by code in some areas.

    Even if a load were connected to two hot lines (same source) and one neutral so that the hot had double the current capacity the neutral can only be overloaded if the load exceeds the wire rating. There had to be a confluence of mistakes to cause that fire. Powering both breaker busses off one inverter would not do it, nor would the proper use of 3-way switches. Even any normal plug-in load would not cause the problem.

    Fortunately inverters fault before breakers blow; they are not as dangerous a power source as the 48kW potential of a utility service.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    The only problem might be with "split" kitchen type outlets or circuits that normally on grid, have three wires (+ ground) going to the receptacle. In these cases, the receptacle is supplied with two hots, one from each leg of the utility supply, but only one neutral. If you have two loads plugged into this split outlet, or connected to such a circuit, the "neutral" only carries the difference between the two loads. If the two loads are exactly equal, the neutral carries no current. It is with these split circuits supplied with two hots and only one neutral, where problems can occur when both hots are connected together in the panel, to one 110 volt supply. In this case, if two electric kettles are plugged into one split receptacle wired with only one neutral, that neutral must carry the total load of BOTH kettles, while each of the two "hot" supply wires, each protected with a 15 amp breaker, only carry the load of one kettle each.
    In other words, each hot is restricted to 15 amps by it's circuit breaker or fuse, and the neutral could end up carrying 30 amps. The cure? Run TWO neutrals to the receptacle, or circuit, one for each hot on the receptacle or circuit if supplying the two hots with single phase 110 volts.
    This has nothing to do with "2 way", 3 way, or 4 way switches.
  • icarusicarus Solar Expert Posts: 5,156 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    I have never seen anyone wire outlets that way, but I suppose it could be done. Typically, a split receptical is wired with 3 wire (red/black/white) with out outlet switiched from a wall switch, the other always on. Wiring two hots from the same phase would have the potential to over load the neutral. Instead of wring it with two neutrals, simply ensure that the two hots are on different phases of the buss. That said, if you are jumping a panel (feeding it all on one phase either from the grid, genny or inverter, there is no second phase so you would be forced to run either 2 2 wires, or a 4 conductor wire. Seems like a lot of trouble.

    Tony
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    Tony;

    It's allowed in BC and I guess NS. Probably not in Ontario. Wasn't in NY.
    It is a bad practice in my book. If the neutral line fails for whatever reason you can have your toaster send 240 VAC through the clock radio!
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    Tony;

    It's allowed in BC and I guess NS. Probably not in Ontario. Wasn't in NY.
    It is a bad practice in my book. If the neutral line fails for whatever reason you can have your toaster send 240 VAC through the clock radio!
    Exactly re the toaster sending 240 to the clock radio. lol
    I don't know the latest code updates here, things keep changing, but some years back, when I built my place, not only was it allowed, it was mandated for kitchen counter outlets and if I hadn't done it, wouldn't have received final approval. Be interesting to know if that's still the case.
  • erneerne Solar Expert Posts: 41
    Re: Inverter and 2 way switches.. and possible issues..??

    I am not good with the written word and am afraid I have confused the matter. Let me try for the final time.

    I did not say the switching was 220V it is 110V but when you use a 110V inverter you can only safely use only 1/2 of your 100 amp or 200 amp electrical box. If you jumper the mains and wire to the other 110V (which should be 180 degrees out of phase) side you are in violation of the NEC. That is when things happen in multiple switching.

    In a normal a/c grid powered house a 3 way switch has a red wire, a black wire, a white wire, and a bare wire. The red wire (hot) is hooked to a circuit breaker, the black wire (hot) is hooked to another circuit breaker and are installed together (side by side) in the main box. The white (neutral) is connected to the neutral bar, and the bare (ground) to ground. This puts the red and black (hot) wires 180 degrees out of phase to each other. If a fault occurs on one while the other is running it allows the breaker to control and disconnect before the neutral is over heated. This is because the 180 degree phase difference is not using the same portion of the neutral. If the mains are run by a single 110 volt inverter and a jumper is installed to make active the side of the panel that should be 180 degrees out of phase “both breakers” are producing electricity to the neutral overloading it amp wise causing a dangerous condition. A normal plug or single light switch has only 3 wires in it. A black (hot) a white (neutral) and bare (ground). Jumping is putting your investment and well being in jepordity, and is violating the NEC.
  • Ralph DayRalph Day Solar Expert Posts: 886 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    When originally wiring my kitchen (1983) split receptacles were required...3 wire, double pole breaker. When I went off grid and from 120/240 to 120 only I just wired the kitchen receptacles with both hots on the same leg (no other way, panel is all same phase). They are separated enough around the counters that heavy loads like toaster, microwave or whatever, are far enough apart that you don't plug them into the same receptacle, ever. They're also never used at the same time, ever. It didn't require re-thinking lifestyle, but it might for some who have lots of countertop appliances close together (and unlimited power).

    Ralph
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    erne wrote: »
    I am not good with the written word and am afraid I have confused the matter. Let me try for the final time.

    I did not say the switching was 220V it is 110V but when you use a 110V inverter you can only safely use only 1/2 of your 100 amp or 200 amp electrical box. If you jumper the mains and wire to the other 110V (which should be 180 degrees out of phase) side you are in violation of the NEC. That is when things happen in multiple switching.

    Nope. Powered from an inverter, jumpering the two legs is merely extending the size of the box. It may technically be a violation of the NEC, but it is in no way a problem or a hazard.
    In a normal a/c grid powered house a 3 way switch has a red wire, a black wire, a white wire, and a bare wire. The red wire (hot) is hooked to a circuit breaker, the black wire (hot) is hooked to another circuit breaker and are installed together (side by side) in the main box. The white (neutral) is connected to the neutral bar, and the bare (ground) to ground. This puts the red and black (hot) wires 180 degrees out of phase to each other. If a fault occurs on one while the other is running it allows the breaker to control and disconnect before the neutral is over heated. This is because the 180 degree phase difference is not using the same portion of the neutral. If the mains are run by a single 110 volt inverter and a jumper is installed to make active the side of the panel that should be 180 degrees out of phase “both breakers” are producing electricity to the neutral overloading it amp wise causing a dangerous condition. A normal plug or single light switch has only 3 wires in it. A black (hot) a white (neutral) and bare (ground). Jumping is putting your investment and well being in jepordity, and is violating the NEC.

    Nope. A normal 3-way switch has three terminals. One is the 'key', the other two the 'points'. The key goes to the hot wire. The two points connect to two points on another 3-way switch whose key then feeds the load with the current returning through the neutral.

    What you are describing is a completely wrong way of wiring a 3-way in. NEVER should you power one load from two different legs and NEVER should a 3-way switch be connected in the manner you describe. Your circuit switches one load between two power legs and serves no purpose.

    If both legs of a 240 VAC service were connected to the same load at the same time it would create a dead short across the 240 feed, and something would go up in smoke.

    Feeding two wires from one leg to any load and back through a single neutral also will not overload the neutral. There has to be a load that exceeds the current capacity of the neutral line. That is the only way this can happen.

    As a note to everyone and anyone, if you go to your local big lumber/hardware/electrical supply store up near the check-outs there inevitably will be a rack full of "how to" books. Get one on basic electrical wiring and read it before you undertake any such project. There's a million ways of wiring things wrong, and many of them can end up burning your house down or killing you.
  • PhotowhitPhotowhit Solar Expert Posts: 4,963 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    Ok I was doing fine, have done a 3way switch for my dad, a quick diagram here;

    http://www.homeimprovementweb.com/information/how-to/three-way-switch-option2.htm

    ...but now I'm worried about using my 200 Amp box by pulling my 200 Amp breaker and the 220 breakers (all on one side and using a 30 amp breaker as my main on that side of the box, guess I need to isolate it. Funny I described my plans to 2 brothers, both electricians and they didn't say anything...

    Time to do some reading...

    Here's a link to assorted ways of doing a 3way outlet, the link above is the way I choose to do it since it was an existing shed turned on from inside, I put switches at the doors. It is pretty convoluted(?)
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • icarusicarus Solar Expert Posts: 5,156 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    There are literally dozens of different ways to properly wire three way switches, depending on application and wiring method. There are on line diagrams that show a whole myriad of different ways to wire them.

    As for jumpering a split phase panel, as 'Coot suggests, it is only a matter of making the hot buss bigger. There may be a technical violation of the NEC, but if the main disconnect is sized for the buss, and the individual breakers are sized for their wire sizes there should be no problem with safety. That said, I am guessing that each leg of a 200 amp split phase panel is rated for 100 amps (the buss rating) so I would not put 200 amps of current on that buss, but I don't think that is what anyone is talking about.

    T
  • PhotowhitPhotowhit Solar Expert Posts: 4,963 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    I was just speaking to my own situation, switching out my 200 amp service to a 3000 watt inverter (120 single phase...lol)

    Pulling the 200 amp main and using a 30 amp breaker as a main on one side of the box, to give some protection to the line, though the inverter is more likely to trip 1st...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Super Moderators, Administrators Posts: 29,351 admin
    Re: Inverter and 2 way switches.. and possible issues..??

    Each Hot Leg of a 200 amp box should be rated to 200 amps.

    However, the Neutral bond point (if rated) would only be rated to 200 amps maximum (I assume everything is rated).

    If you bus the two hots together--I would still only feed them with a single 200 amp breaker (or a total of 200 amps if a 100 Amp inverter and another 100 amp non-synchronized inverter). In either case, that would give you a maximum of 200 amps on the neutral return.

    Obviously, a 200 to 400 amp 120/240 VAC off grid system is HUGE and not anything that most people would be even worried about.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    In this box that hold 6 breakers (or 6 tandems).. you will see how I jumped the phases together..

    connectLOADhots.jpg

    I will be using some 2 AWG to jump them in the 110 AC box.. (this box was used for my panels but I plan on using the SAME box..)

    This will make it into a single 110V AC phase bus bar basically.. I don't see how this can be an issue.. there is no 2 sides to this.. its 1 solid 110V HOT line..

    Just need to install a GROUND terminal block.. and the neutral block is isolated and sitting there already as well..

    For less than $30 (for the simple box) I can't really complain..
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    ywhic wrote: »
    In this box that hold 6 breakers (or 6 tandems).. you will see how I jumped the phases together..

    connectLOADhots.jpg

    I will be using some 2 AWG to jump them in the 110 AC box.. (this box was used for my panels but I plan on using the SAME box..)

    This will make it into a single 110V AC phase bus bar basically.. I don't see how this can be an issue.. there is no 2 sides to this.. its 1 solid 110V HOT line..

    Just need to install a GROUND terminal block.. and the neutral block is isolated and sitting there already as well..

    For less than $30 (for the simple box) I can't really complain..

    The potential problem comes with the neutral block and its connections to the supply. In a 100Amp 220 box, that neutral bar is rated for 100Amps (as would be obtained when the load is all on one leg of the 220 supply.) If you feed the same input waveform to both sides of the 220 volt bus, the current in the neutral could be as much as 200Amps.

    As long as the box is oversized compared to your actual loads (that is your total 120 volt load is less than 100Amps, for example), then this will not cause a problem. It will still not be a "legal" use of that equipment, but it will work.

    You can keep the total current to 100Amps either by feeding the box from a single 100Amp breaker, or by putting a main breaker of 50Amp 220 rating in the panel.
    SMA SB 3000, old BP panels.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    :confused:
    Am I the only one who understands his power source is a 2kW inverter? How is he going to overload 100 Amp bus bars with something that's only capable of putting out <20 Amps?

    Try to stay focused on the topic at hand, please.
  • icarusicarus Solar Expert Posts: 5,156 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    Fact is though 'Coot, we don't know the rating of the load center he is using. It is looking like 50 amp load centre, so a 2 kw inverter would certainly not over load the load centre.

    Tony
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??

    It looks like the Jumper is one from one of the hot legs to the ground buss.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    icarus wrote: »
    Fact is though 'Coot, we don't know the rating of the load center he is using. It is looking like 50 amp load centre, so a 2 kw inverter would certainly not over load the load centre.

    Tony

    Have you ever seen a load center rated for less than 20 Amps? I haven't.
    Fact is I use a Square D 100 Amp 240/120 six breaker load center for this same purpose and have the two sides jumpered and I know for an absolute fact there is no chance that my 3.5 kW inverter will ever overload it under any circumstances. It simply is not possible.

    And again I will state that the inverter will fault before any 15 Amp breaker trips.
  • ywhicywhic Solar Expert Posts: 612 ✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    It looks like the Jumper is one from one of the hot legs to the ground buss.

    Poor photo angle.. I assure you the wire is going over and around that other side to the bottom + side..

    The neutral bar is the one on top..

    Yes it is a 100 amp load center.. QO612L100

    Correct I am running a single 2000w Pure Sine Inverter.. and if at some point I would add a 2nd 2000w unit I would undo the jumper, and just plug in the 2nd unit to that SIDE only..

    so 3 circuits on 1 leg.. and 3 circuits on another.. again just 20 amps max per circuit.. well under the 50 amps 'per + leg'..

    I don't think having all the neutrals ride into the same neutral bus bar would be an issue.. would it??

    Obviously all the GROUNDS would also feed a GROUND terminal bar (not pictured)..
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Inverter and 2 way switches.. and possible issues..??
    ywhic wrote: »

    so 3 circuits on 1 leg.. and 3 circuits on another.. again just 20 amps max per circuit.. well under the 50 amps 'per + leg'..

    I don't think having all the neutrals ride into the same neutral bus bar would be an issue.. would it??

    Obviously all the GROUNDS would also feed a GROUND terminal bar (not pictured)..

    Okay, a 100Amp 220 volt load center is designed for 100 Amps on each phase.

    You do not even need to worry about 50 Amps on the neutral, that limit is actually 100 also.
    SMA SB 3000, old BP panels.
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