120v 10 Gauge Wire Splice

[keepondancin]

What is the approved way of making a splice in a 120v, 10 gauge, multi strand 3 wire, in a junction box? A very trusted person said 120v can be spliced in a junction box with wire nuts. I have been unable to find any junction device that is covered, that would take the 120v.

[Stu Jackson]

Why shouln't butt connectors with heat shrink work?

[keepondancin]

My concern about butt connectors is the least little movement could mean arcing. Using terminal connectors and a screw block could be the same thing, 2 crimped connectors and 2 screws. I am pretty confident there are different requirements for high voltage over low voltage. I haven't had to address this before.

[btrayfors]

If you use a proper crimper....not a cheapie....there won't be any movement. You should be able to support your weight on the splice.

Think I'd use heavy bare butt connectors, covered with heavy wall adhesive shrink tubing.

BTW, how much max. amperage do you plan on this circuit?

Bill

[MARC D]

Butt connectors, weld & heat shrink or use a terminal strip approved for 120 vac.

[keepondancin]

I installed a new Victron 2000W, 80Amp, inverter charger, replacing a Xantrex Freedom 2000. The 120v in and out wiring was just long enough to reach, but I had to run it on an angle, rather than uniformly with other wires. Rather than the expense of all new wire, I want to add a length. The screw strips I see don't have any kind of covering. Maximum amperage, based on the spec sheet is 4000 watts, which equals 33 amps. That is just surge, and I will never have that kind of load, but it still has to be accounted for. I really don't want just butt connecters exposed. Possibly I could put a strip in a surface mounted box, with a cover, but just looking on line, it is hard to figure what would work with what. Finding these items in stock somewhere so it could be held and looked at so that the right combination of parts could be determined, is almost impossible. I could always mount a terminal strip on a piece of wood and fabricate a lexan cover to go over it, but was hoping to find a stock item that would meet requirements and also be difficult to make contact with inadvertently.

[um saudade]

One correct answer is just about anything works if it is done right. If you are doing a splice to continue a run and you won’t be going back in to rewire any time soon, do crimp on rings and bolt the rings together. Doing it this way you can use an end for-end-splice (a removable butt splice if you will) if there is sufficient space in the box. If you can’t end-for-end, do glad handed splices with a crotch and finish with tape. This splice with a crotch is much easier to work with and will waterproof with either tape or heat shrink if done correctly.
Wire nuts are actually pretty good if you use a good quality nut and make the splice waterproof. I fill the nut with NoAlox before application, attach and torque the nut, carefully clean off the excess anti-oxidant, then tape the joint and crotch with 33+. If you are paranoid then give the final assembly a coat of Skotchcoat. Totally waterproof and shockproof for the life of the boat. I have done a lot of taped splices that are then submerged as much as 200 feet below the water line and they do not leak or fail.
Those who deride tape don’t know how to apply the product. Nothing wrong with heat shrink but nothing inadequate with a well done taped splice either.
Leave enough makeup wire to do it easily (six inch pigtails, minimum). Box and cover should be at least 20 cubic inches in size for six #10 wires and does not have to be waterproof as the box simply provides mechanical protection to the wires. If you use a metallic box the box must be connected to the green wire with a pigtail. Do not make this connection without using a junction box.
Any connector with a UL rating will handle the current of the wires it fits. For example any good crimp on fitting that fits a #10 wire will be able to handle 30 amps without heating because that is the rated ampacity of the wire.

[twistedtree]

I'm pretty sure wire nuts are a no-no on a boat. I'd make the connection inside a box, and use either butt splices or a terminal strip with ring terminals. In both cases I'd use connectors with adhesive heat shrink tubing built in, or use separate heat shrink tubing.

[motion30]

Wire nuts. And tape .....really. just strip the wires wrap them together and put some masking tape over it

[hellosailor]

Approved by who for what?

If you are really concerned with doing it right, you know what you have to do. Replace the entire wire run with one uninterrupted run of new wire. Save the old wire for something else, it isn't wasted.

If you don't have faith in the junctions, don't use a junction box. Keep it simple.

[btrayfors]

This isn't brain surgery, folks, else the patient would be dead by now :-)

Here you go.

A good crimper for insulated terminals (Ancor), a good butt connector for AWG10 (also Ancor). Apply splice and heat gun.



And.....voila! A very strong and watertight splice, fully insulated, and easy to do with readily available tools and parts.



Like the black-to-red connection? Hey, you have to leave something for the nit pickers!

Bill

[MARC D]

A good stuff to seal an electric connection (terminal or butt) is to use self-fuse electric tape. This tape is used for in-ground splice job because no moisture can get at the butt splices. We use special heavily glued butt connectors (heat must be applied to melt glue) and than cover with several turns of that tape. You have to stretch it properly according to manufacturer instructions.

But this is a bit overkill to me... We are talking 120 vac here. No arcing will occur. And the 10 gauge wire won't get too warm either. Good quality heat shrink over butt splices is what I have done for the same installation on my boat.

Advantage of the terminal strip is that you can easily measure the voltage present for future troubleshooting.

[keepondancin]

I am probably going to use a terminal block inside a box to make the connections. As far as approved, I want to make sure it is done so that a surveyor won't raise any flags.I like the idea of trouble shooting without having to take things apart. I really don't want to pull all new wires, and proper connections aren't a problem, it is a question as to what a proper connection is. I looked up handy splice, which is good enough for NASA, but it appears to be for single strand. Funny, I got a good price on heat shrink tubing from Harbor Freight several months ago, I use it for lots of different things not electrically related. Turns out it isn't adhesive. So much for "such a deal".

[um saudade]

"Wire nuts. And tape .....really. just strip the wires wrap them together and put some masking tape over it"



Yea, wire nuts and tape. It's quite amazing what those with an average IQ can do with various materials. Some folks have a hard time with just about everything. I guess.

The taped splice is legal as per the NEC (and works very well for many industrial situations far more arduous than the sailboat.) I have taped millivolt control signals and taped 4160/2700 wye. Failures are few. I guess good electrical tape doesn't come with written instructions on the box so it can't possible work.

[Tymadman]

Originally Posted by um saudade

"Wire nuts. And tape .....really. just strip the wires wrap them together and put some masking tape over it"

Yea, wire nuts and tape. It's quite amazing what those with an average IQ can do with various materials. Some folks have a hard time with just about everything. I guess.

The taped splice is legal as per the NEC (and works very well for many industrial situations far more arduous than the sailboat.) I have taped millivolt control signals and taped 4160/2700 wye. Failures are few. I guess good electrical tape doesn't come with written instructions on the box so it can't possible work.

PVC electrical tape falls off eventually. It's correct use is to hold self-amalgamating tape in place while it amalgamates.
In any case, heatshrink and tape are only the means of re-insulating a join - not the means of making the joint.

Mechanical connections (screw, spring clamp, crimp) are used in the electrical trade (not solder!).

Wire nuts can fall off due to vibration and I wouldn't use them (I have been the Electrical Manager of a US factory where wire nuts were used extensively before I got there). I would use screw terminals if you think you might need to undo the join again in the future or if a permanent join you should use proper crimp links (not the automotive type) with the correct crimp tool.

Crimp links which have been properly re-insulated with heatshrink or self-amalgamating tape don't need to be inside a junction box. Use 3 pieces of heatshrink to join a cable with 2 wires: one smaller diameter piece for each crimp link and one larger diameter piece to go over the cable and cover the entire join so the wires are completely covered.

Screw terminals/connectors will need to be housed in a junction box.