Splicing #16 AWG to a #4 AWG

I'm installing a MidNite surge protector on the box that carries the PV-in disconnect. The neutral wire runs thru the box (i.e., its not broken in the box.) I need to attach the #16 wire from the surge protector to the #4 PV-in. I could use a split-bolt for this, but that seems clumsy, not to mention taking up space in a small box.

The solution that I've come up with is to strip an 1/8" of the insulation from the #4, strip and wrap the #16 around the #4, make a mechanical connection and then apply solder. 

Is this an OK solution? Or is there a better one?

Thanks.

Comments

  • cupcakecupcake Posts: 254Solar Expert ✭✭
    how about a using a screw-type bus-bar block with various sized holes... scew the #16 in a small hole then a #4 in a bigger hole, then a #4 jumper going to your box/component..


    :)


    ~1.5Kw PV in parallel
    Morningstar MPPT-60 controllers (2) in parallel
    3 Trojan tr-1275's in parallel 450ah total
    Samlex 2,000 watt 12-volt inverter hardwired


  • geoffleachgeoffleach Posts: 4Registered Users
    cupcake said:
    how about a using a screw-type bus-bar block with various sized holes... scew the #16 in a small hole then a #4 in a bigger hole, then a #4 jumper going to your box/component..

    Thanks. Although the #4 PV-in wire passes thru the box, it is not cut in the box. In fact, the only reason its there at all is to connect to #16 from the surge protector, which is attached to a knock-out.

  • bill von novakbill von novak Posts: 731Solar Expert ✭✭✭✭
    I'm installing a MidNite surge protector on the box that carries the PV-in disconnect. The neutral wire runs thru the box (i.e., its not broken in the box.) I need to attach the #16 wire from the surge protector to the #4 PV-in. I could use a split-bolt for this, but that seems clumsy, not to mention taking up space in a small box.
    Are you sure the 16ga wire can carry the fault current you'll see?  (i.e. either Isc or, if there is a breaker/fuse, the clearing current)
  • VicVic Posts: 2,879Solar Expert ✭✭✭✭
    edited November 2016 #5
    I'm installing a MidNite surge protector on the box that carries the PV-in disconnect. The neutral wire runs thru the box (i.e., its not broken in the box.) I need to attach the #16 wire from the surge protector to the #4 PV-in. I could use a split-bolt for this, but that seems clumsy, not to mention taking up space in a small box.
    Are you sure the 16ga wire can carry the fault current you'll see?  (i.e. either Isc or, if there is a breaker/fuse, the clearing current)


    Believe that the SPD uses  #16 AWG wire   ...  at least implied.

    Stripping the #4 cable,  and wrapping the stripped #16 around it,  is not a very good approach.

    How about one of these:
    https://www.solar-electric.com/insulated-terminal-bus-bar-short-black.html

    Believe that the speced minimum wire diameter is 14 AWG,  although,  you might be able to get away with folding back the bare wire on itself,  under a small screw position in the busbar,  and probably be OK.

    Often,  PV SPDs are mounted in the Combiner,  and a breaker is used as the connection point for the PV positive side PV connection for the SPD ...  some Combiners do not have room for the additional breaker,  especially when doing an SPD retrofit.

    If this addition will need inspection,   adding things like busbars and an SPD,  might not pass inspection ...   it all depends.


    Just my opinion,   FWIW,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 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.
  • geoffleachgeoffleach Posts: 4Registered Users
    I'm installing a MidNite surge protector on the box that carries the PV-in disconnect. The neutral wire runs thru the box (i.e., its not broken in the box.) I need to attach the #16 wire from the surge protector to the #4 PV-in. I could use a split-bolt for this, but that seems clumsy, not to mention taking up space in a small box.
    Are you sure the 16ga wire can carry the fault current you'll see?  (i.e. either Isc or, if there is a breaker/fuse, the clearing current)

    Thewire is provided by teh surge protector, so it should be OK.

  • geoffleachgeoffleach Posts: 4Registered Users
    Vic said:
    I'm installing a MidNite surge protector on the box that carries the PV-in disconnect. The neutral wire runs thru the box (i.e., its not broken in the box.) I need to attach the #16 wire from the surge protector to the #4 PV-in. I could use a split-bolt for this, but that seems clumsy, not to mention taking up space in a small box.
    Are you sure the 16ga wire can carry the fault current you'll see?  (i.e. either Isc or, if there is a breaker/fuse, the clearing current)


    Believe that the SPD uses  #16 AWG wire   ...  at least implied.

    Stripping the #4 cable,  and wrapping the stripped #16 around it,  is not a very good approach.

    How about one of these:
    https://www.solar-electric.com/insulated-terminal-bus-bar-short-black.html

    Believe that the speced minimum wire diameter is 14 AWG,  although,  you might be able to get away with folding back the bare wire on itself,  under a small screw position in the busbar,  and probably be OK.

    Often,  PV SPDs are mounted in the Combiner,  and a breaker is used as the connection point for the PV positive side PV connection for the SPD ...  some Combiners do not have room for the additional breaker,  especially when doing an SPD retrofit.

    If this addition will need inspection,   adding things like busbars and an SPD,  might not pass inspection ...   it all depends.


    Just my opinion,   FWIW,   Vic

    Thanks, Vic. The SPD sits on the outside of the box. As best I can tell, the short busbar you're proposing would do the job if I'm resigned to cutting my PV-in neutral. The question remains as to whether I can fit the busbar in my MidNight Big Baby, along with two 100 amp breakers.
  • cupcakecupcake Posts: 254Solar Expert ✭✭
    you should be able to jam all that into the big baby box... I got me one... there's room...

    :)

    ~1.5Kw PV in parallel
    Morningstar MPPT-60 controllers (2) in parallel
    3 Trojan tr-1275's in parallel 450ah total
    Samlex 2,000 watt 12-volt inverter hardwired


Sign In or Register to comment.