I am interconnecting some strip lights in a closet. They are linkable LED fixtures which each come with a connector cable to link, optionally, to additional fixtures. The connector cables are a bit short for what I have in mind, but I need to use their ends because they have special connectors to link the fixtures and maintain correct polarity.

The connector cables are 18-2 SPT-2 lamp cord. I have a spool of the same type of cable. I am planning to cut the connector cable in the middle and insert an appropriate extension length from my spool. My plan is to splice them using some 22-18 butt splices, then heat shrink them with 3/4" tubing. I will ensure the splices are solid and the polarity is correct. Beyond this, what should I do to make sure this setup is safe?

None of this will be behind a wall. The strips will be against the wall, on their mounting brackets, and the cabling can be secured however. If nothing else, I'll just be using cable staples. I could also run all or some of the cabling through conduits, bracketed against the wall. Or I could simple put the spliced areas within junction boxes. Any suggestions for the safest way to do this are welcome.

I realize there may not be a code-approved way of doing this. The cables will not be in a place where they can be routinely touched, and if I were to move out of the house, I would take all of this stuff down, except for the first of the linkable fixtures which was installed with a junction box by an electrician (it is controlled by a light switch).

If you believe there is no way this can be done without a moderate risk of fire, it would be very helpful to hear why you think so.

Update: This particular line of products now has longer lengths of linking cords available. As a result, no splicing needs to be attempted.

EDIT: This is obviously NOT a duplicate question as erroneously suggested as "What size heat shrink tube is required?" and "How can I safely do something?" are completely different questions.

  • are these low voltage or 120V?
    – bib
    Apr 3, 2016 at 17:48
  • @bib - The power comes off a circuit in the wall and runs into this junction box: homedepot.com/p/GE-Direct-Wire-Linkable-Junction-Box-32612/… which connects the first fixture. The additional fixtures I'm installing would be run from that first fixture's connector jack. The first fixture is this: homedepot.com/p/… I am having trouble determining if the output from that GE junction box is considered low voltage, but as it's meant to run these strips, I would think it is.
    – bubbleking
    Apr 3, 2016 at 17:52
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    The fixtures you list are 120V. Any interconnected wiring will also be 120V.
    – bib
    Apr 3, 2016 at 18:02
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    These are 120V fixtures. Why not use multiple linkable junction boxes on each end of the longer runs and use standard NM-B cable between the boxes?
    – bib
    Apr 3, 2016 at 18:07
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    Reminder - Downvoting a question is for when the question is unclear, lacks research or details and will not be valuable to anyone. Downvoting IS NOT for expressing that you feel I shouldn't attempt the project a question pertains to. If you feel that way, instead of downvoting, leave an ANSWER that explains WHY this cannot be done.
    – bubbleking
    Apr 3, 2016 at 21:45

1 Answer 1


This family of lights uses all 120v wiring which means the full weight of NEC applies. You cannot "freestyle" splices in the manner you are talking, you must use listed products, which those cheapie butt splices probably won't be. They do exist, but O'Reilly Auto doesn't sell them and they don't use $5 crimp tools either.

So here's how you handle "the cord is too short". Legally, splices can only be inside junction boxes. The American gold standard way to splice inside a junction box is with "wire nuts" - for two 18ga. wires I would use the blue or gray ones. Do not use stabs, they are not rated for 18ga.

If GE sells a listed method to attach their special connectors to your lamp cord, go for it. Otherwise you can only use it between junction boxes, which means 2 junction boxes. If you want to do it in one junction box, then buy 2 cords long enough to give you 8" slack inside the box, and splice there.

But I have to say: why on earth are you using this family of products? Don't get me wrong, GE's quality is first rate, but why wrestle with 120v products when you can get the same thing in 12v that's much easier to work with.

Also, these prices are way beyond insane, at least 3-4 times what I've seen in quality 12v products. IKEA has a broad selection of 12v products at sensible prices. 12v makes the products cheaper because they do not need expensive voltage converters in each lamp. I buy cheap Chinese LED strips for $7 for a 16 foot roll, I mention that only to shake you out of a notion that $60/foot is a normal price for these things.

  • Thanks for this great answer. I hope you don't mind if I pick your brain for how to continue. Firstly, the butt splices are UL listed. I already owned a wire stripper/crimper tool made for a number of AWG sizes. However, I can take your word that wire nut splicing is a better idea. More on that momentarily.
    – bubbleking
    Apr 3, 2016 at 21:51
  • As to why I chose these products, the short answer is brightness. The main fixture has over 1000 lumens and I was hoping to flank the lower sides of the closet with 2 strips of 800 lumens each.
    – bubbleking
    Apr 3, 2016 at 21:55
  • Well you will certainly never have to worry about the units failing. GE makes good stuff. Apr 3, 2016 at 21:59
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    Good point. We are really stretching 400.7 which is the part permitting flexible cords for luminaires. Not sure that allows for junction boxes enroute in luminaire cabling, but it definitely doesn't allow for splices outside a box. The edges of the cord should be different: typically one edge will be ribbed and the other not. Commonly, not universally, ribbed is neutral. If there are only 2 pins, they are not conveying ground and are only using the 3rd pin for keying. Apr 3, 2016 at 22:09
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    Yeah, that's a question for the code lawyers: I argue yes since it is only to extend wiring to luminaires. The more fundamental issue is that when things get complicated and ugly like this, that's God trying to give you a hint. It seems fairly obvious GE hasn't thought this product through, or HoDepo fails to stock key parts of it (which happens to me every time I try to use a proprietary system of products from them). Try other vendors for the length of cable you need, or couplers. Or exploit their rather good return policies on the kaboodle. Apr 3, 2016 at 22:27

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