contact

[sitelights]

Contact is everything in low voltage. Over the years I've seen many techniques for water-proofing a low voltage connector but these connectors are always "Wire-Nuts" (this term is registered by Ideal Industries, Inc.) or a similar variant under a different name. These terminators are the standard in most electrical wiring and a number of manufacturers supply them pre-loaded with a water-proofing gel. (I've also seen a method for water-proofing which is simply potting the connectors in gel in a small bag closed with a twist tie.) These twist-on connectors are suitable only with solid copper wire; stranded wire and twist-on connectors yield a very poor connection that is likely to fail in a wet or dry environment. The thin strands in outdoor low voltage wire (over 100 strands in 10 gauge) are easily damaged in both wire stripping and in attempting to achieve a solid connection by twisting to the point where the strands are severed by the spring within the connector body. I have never used twist-on connectors in my low voltage outdoor work. The ideal (and it is from Ideal) connection is made with their Buchanan Construction Products 4-way tool (cat. # C-24), crimp connectors (2006S and 2011S) and insulating caps (2007 and 2014). The solid copper connectors (a barrel with open ends, one end slightly flared) about a half inch long, are slipped over the bundled strands (no need to twist the strands together) and then crimped with the 4-way crimp tool. The tool exerts tremendous pressure from four points around the barrel making a mechanical connection that is stronger than the cables being spliced. You can see exactly what you are doing at all times. The insulating cap snaps onto the flared end of the barrel and if you want a waterproof connection you merely fill the cap with GE II silicone sealant (product # GE280 clear) before you snap it on. To ensure that there are no voids in the silicone, rotate the cap by twirling it between your fingers to fully surround the sheaths. This method yields a fool-proof and failure-proof connection that will last indefinitely in the harshest of outdoor environments. Questions?

[mmontesi]

Looks like an ideal way to make a connection. Why not use the pre-capped connectors?

[sitelights]

The pre-capped connectors work well with light gauge stranded wire but are awkward to use if the connection will be potted with silicone. Remember that this technique using large or small crimp barrels will join 3 #10 stranded (large #2011S) or 2 #10 stranded (small #2006S) and you can sneak a #18 wire into both if you also have a fixture lead at a point where you are splicing 10 gauge. The pre-capped connectors were developed for speed in joining light gauge wire; the 4-way crimp/barrel/cap method yields high strength, water-resistance and the ability to join heavy gauge stranded low voltage cable. We never use 12 gauge cable since it limits current carrying capacity in applications where it is the opposite of what you are trying to achieve.

[mmontesi]

I see. So, this method is preferred for splicing the main cables, however, you would use the pierce-point for connecting fixtures as a preference? (As per your other post)

[sitelights]

We seldom cut and splice the main cable; there are only three circumstances where this is necessary:

(1) to repair a damaged piece (2) to extend the cable (3) to achieve a "T" configuration. The only instance where we actually splice in a fixture lead is when there happens to be a fixture near the splice; this saves us a pierce-point connector.

We invariably use a small Buchanan crimp to attach the last fixture on the main cable run; this saves a connector but, more importantly, it seals the end of the main cable to prevent moisture penetration. What you want to visualize with the Buchanan crimp is that you are creating a solid mass: the extreme pressure generated by the tool compresses the copper strands and the crimp barrel into a single piece of copper (actually gas tight) which can then be protected by the silicone filled cap. In technical terms you have created not only a waterproof but an explosion proof connection in that there is no gap to create an arc.

[sitelights]

A picture is worth a thousand words. The image attached to this post illustrates the 10.03.01 previous post. This image contains a lot of stuff.

Clockwise from top right: A well-used Buchanan tool (it has about 100,000 miles on it so to speak) in the open position; note the A-B embossed on the left handle. With the slide mechanism one can select the setting to use a large crimp (B) or a small crimp (A).

This tool is widely used by electricians to join ground wires in which case the crimp caps are not used. With solid wire it is recommended to twist the wires together. With stranded wire each conductor is separately twisted to ease the wires into the tubular copper connector.

Between the handles of the C-24 tool are large splice cap crimp connectors ("barrels" we call them) model 2001S and splice cap insulators ("caps" for short) model 2014. The bare crimp splice shown has three 10 gauge and one 18 gauge conductors joined. The barrel is flared at one end for three reasons: it acts as a stop in the tool, makes it easier to twist the conductors into the barrel and the rolled edge is captured securely by the toothed brass ring within the snap-on cap.

If one closely examines the image (it helps to zoom on the crimp) it can be noted that all the ribbed conductors are joined maintain polarity. It is a good idea to form the habit of maintaining polarity in case of a subsequent looping of the cable. The two smooth conductors to the right of the cap overlap to form an F ; just above the crossbar a part of the imprinted blue footage marker can be seen. These one foot increment numerically sequential markers allow exact calculations when planning or billing.

The tube of clear GE II is called a "sealant" and a "glue" on the label; take your pick. Read the text. This product is used to fill the caps prior to snapping them on to the crimped barrel. If the cap is filled the crimped barrel will displace about half of the sealant which forms around the conductors to eliminate any voids. Since the cap and the sealant are translucent the fill can be visually confirmed. No other method of waterproofing the splice is superior to this type of join.

The tool on the left is new and is closed to show the pins that crimp the barrel. The small barrels (2006S) are also flared and the two 10 gauge and one 18 gauge conductor are joined, crimped and capped (2007) the same as the larger size. If properly used, the crimp splice is stronger than the wire; The wire will break before the conductors will slip out of the crimp. Twist on wire connectors (Wire-nut (r) or similar types) can be easily pulled apart; especially the gel filled connectors touted for their integrity and water resistance.

In twenty years of using the Buchanan crimp we have never had a single failure.

[eonibm]

I am wondering how one can tell from that pic that polarity is maintained? Is polarity not maintained by making sure that the same wires of each cable are connected at each end by noting what you are connecting (sorry I am a newbie so I don't know all the terms). ie, can't polarity also be maintained using marrets and remembering what wires of the cable you connnected on the other end and connecting the same wires at the opposite end?

Leon

[eonibm]

Ok call me dumb, but I really magnified the pic and just realized that one side of the wire is ribbed and one smooth so I guess you crimp the ribbed wires together and the smooth wires together and that maintains polarity.

Leon

[Mike M]

The tube of clear GE II is called a "sealant" and a "glue" on the label; take your pick. Read the text. This product is used to fill the caps prior to snapping them on to the crimped barrel. If the cap is filled the crimped barrel will displace about half of the sealant which forms around the conductors to eliminate any voids. Since the cap and the sealant are translucent the fill can be visually confirmed. No other method of waterproofing the splice is superior to this type of join...

...In twenty years of using the Buchanan crimp we have never had a single failure.

So this sealant is not only waterproof like silicone, but it hardens to seal out the elements? Awesome.

Tough descision regarding connection methods, but I can definately rule out twist-ons.

I'm down to this, if anyone wants to argue which is best for which application, or if one is best for all applications:

1. Buchanan crimps and caps w/sealant.
2. Brass connectors with screws (Ace), and heat-shrink tubing.
3. Soldering, and using tin-coated wires.

Let's say they all work without failure for many many years, and that they each have an easy way of inspecting for a reliable connection; the next things to consider are cost and ease of method, methods best for specific applications, and methods that convince/assure our prospects (I mention this because people like the reliable sound of "solder" and "marine grade," etc).

I don't like the greese tubes because the wires can slip out, and I can't easily visually check to see if there is any uncovered wire, and I don't like the gaps at the "unsealed" entrance of the wires. I searched and found a 3M set-up with a cap that locks into the tube, but the cap is a twist-on. At this point, even with the crimp, I don't see how the wire will stay in, and it's hard to see if it's all the way in. I think it would work better if it was crimped again over the insulation about two inches up from the end, to keep it locked in place. But then again, I like the "sealant" idea better in the Buchanan method than the "greese" idea.

Anyone want to chime in? I would really appreciate.

Thanks,

Mike M

[Mike M]

Oh yeah, and about pierce-point connectors...

Can these be safely used? Which ones and how are they protected? I've been throwing away my Kichler ones that come with the fixtures.

Mike

[sitelights]

Search: "buchanan" and "pierce-point" and also look at the post "pierce point connector types" in this forum. I have expressed myself fully on these topics and have nothing further to say except that the list of posts in a given forum may continue on page 2, 3 and so on at the lower right on the page. The post referenced above appears on 2 for example.

[Eden Lights]

I use a silicone filled 8mil poly bag with a wire tie to allow the silicone to be massaged around the wires and inside the cap. I experienced some water entry when making a T connection when only filling the wire caps. Entry was right up the middle of the three wires.

[Mike M]

My question is why use bags if grease tubes are available?

Eden's failure leads me to suspect that the sealant, as hardened, becomes flexible, which permits it to be opened if the wires are pulled, or, the sealant shrinks as it sets over time, or when temperature drops, forming gaps, etc.

He uses a bag with more sealant, but why not put the crimp and sealant-filled cap into a grease tube? The grease would not shrink or pull apart. However, I still think that since the grease is a fliud, it may allow the connection to slide down the tube, or worse, it may ooze out over time (is this possible?). Which makes me consider the advanced uses of silicone gels. Could this be a better medium for the grease tubes?

Anyways, I like the idea of sealing the sealant with something that can fill in or protect gaps made for whatever reason. The tubes are readily availlable, quick to install, and inexpensive.

[Mike M]

I'm not sure why, but I am really obsessing over the connection topic. To me, it is the single most important issue at hand. It is our systems at the weakest point, and each connection represents a greater system and philosphy. For example, you can judge a lot about a manufacturer by the connections they suggest we use.

I could probably use any number of techniques and rarely get call-backs because of failure. And yet, I obsess.

It just seems to me that the perfect connection would have these traits, and I have yet to find the connection with all of these:

1. Resistence to harsh soil environments.

2. Tolerance for environmental interference (inadvertant tugging at wires, root development, etc.).

3. Economical: reasonable in duration of method and cost of materials, readily available on the market.

4. Consistency and replicability: each splice likely to be consistent and not reliant on only surgeon hands or very highly trained skills.

5. Appearance: let's face it, it should look good and make sense to our consumers. This is for both in-line splices and hub connections.

6. As if it were a part of a commercial airplane, or the space shuttle, it should have a back up: If the first level fails, the second will back it up.

Anyone got any feedback??

Thanks, Mike.

[Mike M]

Contact is everything in low voltage

There should be a rule about posting replies to your own posted replies, but since there are no rules or etiquette guidelines, here I go.

If "contact is everything," then why is it there is no mention of splices in Janet Moyer's book? How come nobody wants to make a better connection? Why am I talking to myself?

[sparkync]

sitelights, is this GE II silicon something that can be found at Lowes or Home Depot stores? I'm all for doing the best connections for duration of time. Thanks

[sitelights]

At both stores. The name has changed over the years; it was recently "GE Silicone II Household Glue" (originally "GE.....Sealant") and now "...Kitchen & Bath". The stock number for the new product is GE 284 in the 2.8 FL OZ tube; this is the clear (recommended) type in the most convenient size. Do not buy the type that fits into a caulking gun; that is a different product.

As far as I can determine the formulation is the same with the addition of a miniscule amount of "mold and mildew protection". This is to be expected now that it is marketed for kitchen and baths. The product can be used on "surfaces that will not exceed 400 degree F". The product also comes in black, white and tan but the clear allows you to see what you are doing and is less messy.

Recall that I have recommended the product only for use with the Buchanan crimp caps.

[sparkync]

sitelights, I got my Lowes bill today, and lo and behold there was an advertisement for the GE Silicone II sealant. Thanks for the input again.

[sitelights]

In response to Mike M's question from June 30, 2007:

The books by Jan Moyer have been reviewed in the Book Review forum. The 2nd edition review has not yet been posted. Try the Book Review forum for more info.

While there is substantially more technical information in the second edition compared with the first neither constitutes an installation manual. If you look at the review of the second edition you will see that it consists merely of the table of contents. There is subheading in the "Elements of a Wiring System" section (page 181-183) that evaluates various splicing techniques. The text could be superficially construed as describing the Buchanan method but it actually describes a device known to electricians as a "rocket" (illustrated on page 185) which is more often used for 120v splices.

Incidentally, I note that UL1838 revisions are coming up for a vote by the STP (Standards Technical Panel) and that the panel now includes Jan Moyer. I've been a member of that panel almost 10 years as the sole person that actually is in the design/install business. Jan's participation will bring another viewpoint and a valuable reality check for the theoreticians.

[Lightguy]

^ As always thanks for your contributions.
I only use Buchannans and have done so with great results for years.

David Knapp
Artisan Outdoor Lighting