How do I connect 4 awg stranded wire to neutral and ground? This wire seems too big.?

Question

I'm adding a subpanel to my garage and using 4, #4 awg stranded wire: 2 hot, 1 neutral and 1 ground. Looking at my main panel, I don't see how this thick 4 awg will fit into the neutral and ground connections. Is there an adapter I should be using? Also, I'm using 2 black wires as hots and 1 black wire as ground. The neutral is white. I figure I'll strip the ground wire bare in the box to show it is ground. Am I doing something wrong? To late to buy new wire, it's already cut and snaked. Thanks.

Answer 1

#8 is sufficient for neutral and # 10 for ground, using 8 or # 10 for lines.

Answer 2

You didn't specify what type of wire you have and that makes a big difference in the answers. I will take a wild guess and pick THHN or THWN copper wire. If this is not correct, this answer will not be correct. Using the 2005 National Electric Code. Table C.3 states a 1 1/4 flex conduit will allow 6 #4 conductors of the type I picked above. THHN or THWN. Your #4 wires are rated for 85 amps at 75C in Table 310.16. However Table 310.15B6 allows #4 copper to be used on a 100 amp service. Using the 100 amp figure, Table 250.122 specifies a minimum of a #8 copper wire for the equipment grounding conductor. Your ground wire in other words. Now for the neutral conductor. You mentioned a number 10. That is not allowed. 250.24C1 states the grounded (neutral) conductor shall not be smaller than the grounding electrode conductor specified in 250.66. Table 250.66 specifies a #8 copper wire. So your neutral cannot be smaller than #8. And you still need to do the proper calculations that show that a #8 will be large enough to handle the current imposed on it. Any more than 50 amps will require a larger wire. Most inspectors will not allow you to go more than 1 size smaller on a neutral. That would be a #6 copper wire. Burned off neutrals can be very dangerous both to people and equipment. So you are allowed to pull another #6 neutral and a #8 ground into your 1 1/4 flex conduit. Don't take electrical advise from the untrained and unqualified people on yahoo. Especially those posing as electricians. They are guessing. If you need more help just email me. PS: most service panels will take a #4 wire in the neutral and ground busses. Just a little struggle to get them in there. But they are rated for #4.

Answer 3

You can get a ground lug that will fit the #4 awg ground wire and it will mount on the existing ground bar in your panel. Your panel will need a couple empty spaces in the ground bar to make room for mounting the lug. Do not listen to those who say to use a smaller ground wire. Many do not understand the importance of a good and solid ground. Make sure you do not get the neutral wire confused with the other black conductors, get some green marking tape for the ground, and some white marking tape for the neutral, and after making sure you have the right one mark it with the tape.You may also need a new lug for your neutral wire, and that fits on the neutral bar.

Answer 4

frank m has got ya going, the ground lug can be fastened right to the panel, drill a hole and bolt it in, make sure it's tight, the neutral should have a big enough lug if the hots do, if you have to put a new lug on the neutral, "make sure you get it tight". what ever you do "NEVER CUT STRANDS OFF". marking the ground with green tape would be better than striping it, make sure you have the same wire as ground on both ends.

Answer 5

, OK strip the black as the ground paint it green, [whats left of the insulation, ]that goes to the ground screw, on the box, use 1/2 of the strands or what will fit, cut the rest off,
the white goes to the neutral lug, that will make it up to code, dont forget to strip and paint the other end of the ground green also, at the feed end, ,
Green is always ground,