Need PV combiner box that can handle two seperate outputs for 2 inverters.

rollandelliott
rollandelliott Solar Expert Posts: 834 ✭✭
I'm putting together a 10KW system that is run off two 5KW inverters. I guess the traditional way of doing the wiring is to have a fuse/combiner box for each inverter.
I'm wondering if there is a fuse/combiner box that is wired to handle two seperate inverters? all within one box?
I like this box
http://www.youtube.com/watch?v=Z2-iMza2MLQ
made by midnite solar. Skip the video until 3:50 and you can see how it is wired. However All 6 of the fuses are combined to ONE positive and ONE negative wire
for my application I need 3 fuses combined into a Plus and Negative out put
AND a seperate 3 fuses combined into a Plus and Negative out put

does anything like that exsist?

Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    Out back FLEXware PV 12 is what your looking for I think.

    Specs
    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.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    Are you looking to tie the DC side in one box or the AC side in one box (generally, the NEC would want separately derived power sources to have separate boxes/conduit/wiring to avoid shorts/mis-wiring).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SolaRevolution
    SolaRevolution Solar Expert Posts: 410 ✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.
    Photowhit wrote: »
    Out back FLEXware PV 12 is what your looking for I think.

    Specs

    Yea. You'll need the combiner that comes with two neutral bus bars. It will also have two positive paralleling bus bars.
    You should be fine with the NEC as long as the Combiner is listed for this use. Do check out the wire ampacity charts. With four output "current carrying conductors" in the same conduit you will need to derate the wire by another 80% factor. NEC Table 310.15(B)(2)(a). This is in addition to all of the other wire ampacity rating issues including 1.56 x Isc and any tempurature or voltage drop considerations.

    -Alex Aragon
  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    OK cool thanks for all the help everyone!
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    SolarBOS makes a DC combiner box with two isolated outputs.
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    And, saw this post on the Midnite Forum yesterday, stating that the MNPV12 also has dual, isolated neg busbars, for products made in the past year of so-- that Forum thread:
    http://midnitesolar.com/smf_forum/index.php?topic=590.0

    This is the (indirect) link to the MNPV12:
    http://www.midnitesolar.com/productPhoto.php?product_ID=144&productCatName=PV Combiners&productCat_ID=9&sortOrder=9

    EDIT: well the link to the Combiner will not select the MNPV12.
    SO, if anyone wants to see the MNPV12, use the second link above, and choose PV Combiners, and then MNPV12.

    The photos are old, and do not show the two neg busbars, but Ryan, the MN Tech support chief mentions that they are there in units made within the past year or so. Have not looked at the pricing of MN vs OB. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    Hi Vic,

    I think the 'Specs' link I provided clearly shows the seperate Negative Busbars. I think I read somewhere that they have a link between the bars that must be removed to use them on seperate systems.
    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.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.
    Photowhit wrote: »
    Hi Vic,

    I think the 'Specs' link I provided clearly shows the seperate Negative Busbars. I think I read somewhere that they have a link between the bars that must be removed to use them on seperate systems.
    Does it have separate positive busbars?
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Need PV combiner box that can handle two seperate outputs for 2 inverters.

    Photo,

    Well, have not seen any pics that show the dual neg busses, but believe that they ARE there. The venerable OB PSPV Combiner had a position for the second PV Neg buss. This is what I used on a recent install, as it was on site, just added the OB optional Neg buss. The MN stuff is designed by the same guy/crew ... so ...

    And ggunn, Well, the manual shows the segmented Pos buss, which is also carried over (in general) from OB. Link to manual:
    http://www.midnitesolar.com/pdfs/MNPV12_&_16_Instructions_Rev_-.pdf

    Am very pro Midnite, as they are very aggressive in addressing what the market seems to demand. AND, MN gives great support via e-mail, phone and on their Forum. OB seems much less aggressive to me, but give very good support, especially by phone. Schneider seems to have NO regard whatsoever to their customers. They took down the Xantrex Forum years ago, and generally in my experience give inconsistant, incorrect "support" to their paying customers.
    YMMV, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.