Connecting 12v Prosine 2.0 to breaker box / sub panel

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  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel

    Lets let "Hairfarm" respond, I suspect he is calling 2+ground 14/3, not uncommon when starting out. For solar, or indeed for any new construction, it's always nice to go at least 1 wire size above what's required.

    Blackcherry04, I have a 500 watt Exeltech that was used for a hand made appliance, It has a tiny 20-22 gauge wire leading to a little 3 prong connector that is the 120 output, I was amazed at how tiny the wire was. I guess they are just worried about heating and over the 2" the wire travels I guess that's fine.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Photowhit wrote: »
    ... over the 2" the wire travels I guess that's fine.
    Good point, and the NEC and UL (for inside devices) both recognize this. If the concern was voltage drop, then the short wire can be ignored. If the concern was heating, then 2" is OK provided that the attachment at one or both ends is acting as a heat sink. With one end connected to a bad three prong connector with high contact resistance, that end could actually get hotter. But as long as the other end is heat-sinked effectively, still no problem.
    SMA SB 3000, old BP panels.
  • Hairfarm
    Hairfarm Solar Expert Posts: 225 ✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Lets let "Hairfarm" respond, I suspect he is calling 2+ground 14/3, not uncommon when starting out. For solar, or indeed for any new construction, it's always nice to go at least 1 wire size above what's required.

    Oops. I happened to be referring (for some reason) to the one section of 14/3 wire that was necessarily run between 2 three-way (not single pole) switches. The rest of the cabin is, in fact, run with 14/2. My bad.

    Questions:

    1) On page 3-5 of my inverter manual it states " AC Output: The circuit breaker or fuse must be rated at no more than 30A and must be approved for use on 120Vac branch circuits. The wire used between the PROsine and the AC output breaker must be sized to match the AC input circuit breaker’s rating. The wire from the AC output breaker to your loads must be matched to the rating of the AC output breakers. This doesn't imply that I need / must install a 30A breaker in my AC load center, right? I was only planning to feed the inverter AC output into several 15amp breakers instead for my circuits. (documentation: http://www.xantrex.com/documents/Inv...1_rev-C%29.pdf) Can some please take a peak at my documentation to see if I'm interpreting this correctly?

    2) One other major screw-up on my part. The entire cabin has been wired with 14awg wire. I just checked my Xantrex Prosine 2.0 inverter and it has 12awg wire coming out which will eventually be tied into the Square D AC load center. Does this mean that I short changed myself?! In other words, since I'm using 14AWG wire that limits my AC breaker fuse to 15A, correct? If I had matched the Prosine's 12awg I could used 20A breakers right? AARRGG! What does this mean exactly? That I can't take advantage of a slightly higher breaker amperage rating?

    3) Should I install an AFCI in my AC load center? I will be installing GFCI's in my outdoor outlets and kitchen / bathroom areas. Just wondering if anyone had thoughts on an AFCI for offgrid applications. Actually, my cabin in only 480Sqft, so I don't really have a bedroom or living area to single out which is what an AFCI is recommended for.

    4) In some AC panels that I've "googled" I see that many people have connected their green ground wires directly onto the neutral bus along with the white neutral wiring, side by side. Even my own rental home is wired this way, btw.

    Like this diagram:
    Attachment not found.
    And this one:
    Attachment not found.

    The neutral bus also has ground wires attached too in addition to neutrals. My plan was to tie the neutral and ground bus together but not share a single bus. But I guess it's all the same thing really, right?

    Thanks for all the input everyone!
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Hairfarm wrote: »
    3) Should I install an AFCI in my AC load center? I will be installing GFCI's in my outdoor outlets and kitchen / bathroom areas. Just wondering if anyone had thoughts on an AFCI for offgrid applications. Actually, my cabin in only 480Sqft, so I don't really have a bedroom or living area to single out which is what an AFCI is recommended for.

    When you decide this, keep in mind that AFCI consumes power, about 2W, which translates to 17.5kWh per year.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel

    1 - You don't have 20 Amps at 120 to play with, 2000/120= 16.7 Amps so a 15 Amp breaker may keep you from having the prosine kick out.

    2 - So long as your under the rated breaker your fine, might even suggest a heavier gauge from Inverter to Sub panel (if you break the bond at inverter it can be your main.

    3 - "I will be installing GFCI's " Your coming off a GFCI on the Prosine, I don't think you can stack GFCI outlets, I also don't think a Arcfault will work behind a GFCI, but plead ignorance. (I read up and it appears that stacking GFCI's is fine)

    Your Neutral and Ground white and green or bare, should be connected(Bonded) in one place and only one place. Someone stated that if you have a GFCI on your inverter you have a bond there, so you should break the bond at the panel if this is the case. Regauardless you will not be able to connect with the GFCI if you don't break the bond between the Nuetral and Ground ain the box. Xantrex appears to have implied that it doesn't have a bond (can't recall what you had said about your call with them, and am leaving work, I'll reread later at home and perhaps I didn't understand that)
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel

    I guess you read this ?? on page # 3-6. It's tricky because with generator input it's not bonded, so you'll have to create one with the generator if you use it.

    Neutral Grounding:

    The neutral conductor of the PROsine’s AC output circuit is automatically
    connected to the safety ground during inverter operation. When AC utility power
    is present and the PROsine is in Charger mode, this connection is not present, so
    that the utility neutral is only connected to ground at your source panel. This
    conforms to National Electrical Code requirements that separately derived AC
    sources (such as inverters and generators) have their neutral conductors tied to
    ground in the same way that the neutral conductor from the utility is tied to ground
    at the AC source panel.

    http://www.xantrex.com/documents/Inverter-Chargers/PROsine-2/PROsine_2.0_User%27s_Manual(445-0089-01-01_rev-C).pdf
    .
  • Hairfarm
    Hairfarm Solar Expert Posts: 225 ✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Neutral Grounding:

    The neutral conductor of the PROsine’s AC output circuit is automatically
    connected to the safety ground during inverter operation. When AC utility power
    is present and the PROsine is in Charger mode, this connection is not present, so
    that the utility neutral is only connected to ground at your source panel. This
    conforms to National Electrical Code requirements that separately derived AC
    sources (such as inverters and generators) have their neutral conductors tied to
    ground in the same way that the neutral conductor from the utility is tied to ground
    at the AC source panel.

    That is correct. I did see that in my manual too. Thanks.

    My generator won't be grounded. It will only be rolled out of the shed and used when needed and won't be "living" near any ground source to use effectively. Xantrex tech says ungrounded generators are ok to use, even MSW ones. The default, factory position of the inverter bonding screw is "Auto bonding to ground in invert mode". However, my "shore-power" (actually my generator) will not be grounded. Therefore, I'll have to manually relocate the inverter "bonding" screw in the other hole, the permanently "unbonded in all modes" position. But then I will definitely have to bond the neutral to ground in my AC load panel. That way, I can hook up my non-grounded generator and be set up correctly. The "Auto bonding to ground in invert mode" setting assumes that the shore power (usually for prosine inverter applications like RV's, Boats, etc) will always be grounded. But in my situation my "shore-power" won't be grounded, so I use the "unbonded in all modes" setting and bond at the panel to "force the issue". This is how it was explained to me by Xantrex.

    I'll try to clarify the GFCI issue that applies to my specific inverter as it was explained to me.

    The GFCI on my Prosine is on a completely different "circuit" and has nothing to do with the main AC out wiring. I think there might've been some confusion about this in regards to some posts about my Prosine. My Xantrex Prosine 2.0 product was offered originally in two flavors, one model had a GFCI outlet wired into the back of it. But it also had another set of outgoing AC wires for a load center / breaker box, as well as a set on incoming wires for a generator or charger.
    The second "flavor" that was offered did not have a GFCI on the back, only an AC out/in wiring scheme like the former. It has a simple metal plate covering the AC side instead of a GFCI outlet like my model. I didn't even care about the GFCI when I bought it on Craigs list. It was just a great deal.

    The GFCI can be considered a second "circuit within" the inverter. The GFCI is a two outlet receptacle and has nothing to do with the other AC out wiring. Please see pic:
    Attachment not found.

    I'll leave the GFCI in place because it will be useful to have and wire the second set of AC out wiring to my load center. This second AC set of wires will have nothing to do with the GFCI already installed in my inverter. They perform two separate, isolated functions. I'll have no problem wiring a GFCI in my kitchen, bath, and outdoor areas. I've decided not to use an AFCI since my cabin is one big room anyway. That and the fact that an AFCI uses monitoring current, a fact brought to my attention by Northguy which I later researched. My Prosine will be fed into a QO load center by way of 6 circuits protected with 15amp breakers, etc. If I occasionally need a 30 amp power supply, I guess I'll have to turn on my 5k generator for that.:cry:

    Also, I bought LED fixtures for the interior / exterior of the cabin. 15 LED lights in all. All are rated for 9 watts per bulb. Even if all of the LED bulbs are on at once it will only use 135 watts. I just can't get over how cool that is! I explained this to my neighbor who still uses a 150 watt incandescent bulb, (more than the total wattage of all my 15 LEDS powered up at once) in his workshop and he made beeline to Home depot to see for himself:D

    Thanks,
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel

    I'm sorry, I wasn't aware that you had both a hardwire and a GFCI outlet, I thought you had intended to plug into the GFCI. I have several 1800watt prosines and they don't have both, rather an either or. Infact, I just purchased my first with a GFCI and will have to run it as a dedicated curcuit or figure out how to disconnect the bond in the inverter if there is one, still reading as it's a military unit and has a printed manual larger than available online. Sorry if my comments lead to any confusion. My bad.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Photowhit wrote: »
    (I read up and it appears that stacking GFCI's is fine)
    AFAIK, the only sure problems with stacking GFCIs are that when there it a trip, you can have problems finding the one that tripped, and also that with GFCIs that will not reset without power applied, you have to go about the trip-finding and resetting process in order from the panel out toward the load. Otherwise if you try to trip a device to test whether it is getting power or not, you may actually be unable to reset it until you have restored everything upstream.
    The other problem I think you see more often is that one of the GFCIs may be hidden inside a jet tub enclosure or other odd place.
    Now GFCIs used on ungrounded circuits for partial protection may be less tolerant of stacking.
    SMA SB 3000, old BP panels.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Connecting 12v Prosine 2.0 to breaker box / sub panel
    Hairfarm wrote: »
    That is correct. I did see that in my manual too. Thanks.

    My generator won't be grounded. It will only be rolled out of the shed and used when needed and won't be "living" near any ground source to use effectively. Xantrex tech says ungrounded generators are ok to use, even MSW ones. The default, factory position of the inverter bonding screw is "Auto bonding to ground in invert mode". However, my "shore-power" (actually my generator) will not be grounded. Therefore, I'll have to manually relocate the inverter "bonding" screw in the other hole, the permanently "unbonded in all modes" position. But then I will definitely have to bond the neutral to ground in my AC load panel. That way, I can hook up my non-grounded generator and be set up correctly. The "Auto bonding to ground in invert mode" setting assumes that the shore power (usually for prosine inverter applications like RV's, Boats, etc) will always be grounded. But in my situation my "shore-power" won't be grounded, so I use the "unbonded in all modes" setting and bond at the panel to "force the issue". This is how it was explained to me by Xantrex.
    Ok, that works. How do you plan to use your Generator Output ?? Is it all going to the Inverter Input and through the transfer switch ??