taping wire

[sparkync]

Is it necessary in low voltage lighting, to tape the connections or the ends of cables or the exposed pierce points when moving a light in a difference place along the cable. I read in one brochure, that it was not necessary with 12 volt fixtures and that there was no shock hazard. What is your opinion.. Thanks for the reply....

[sitelights]

Good question. Exposed cable ends allow moisture to wick into the stranded wire and cause oxidation; this oxidation extends only an inch or two into the cable end and is of no consequence UNLESS there is a pierce point connector in that area. I always terminate the cable end with a crimp connector to the last fixture lead when I am not using a "looped" cable configuration. Search "Buchanan" for details.

Some main cable (I use 10 gauge exclusively) has a soft PVC sheath; some cable uses a hard PVC sheath. The soft sheath does not deform the pierce points and, with 10 gauge, a good connection is made because the points are more likely to be completely within the strands of the copper conductor. As a bonus, the soft PVC sheath "heals" better when a pierce point connector is removed. I've never bothered to tape over the pierced cable when removing or moving a connector; I have not found significant oxidation at the point where the cable was pierced but this is easy to confirm for yourself. "Hard" cable (for example the Paige product) does not "heal" and it actually deforms the points, particularly in cold weather; this is why many installers "hard wire" with twist-on connectors. The distribution (main) cable of choice seems to be 12 gauge (a poor choice in my mind) and the combination of hard sheath and small (relatively) conductor size results in a failure-prone pierce point connection. I have plenty to say on this topic in other posts. Interestingly, I seem to recall (correction welcomed) that Focus used to supply a small piece of soft, sticky black material (rubber?) that was to be placed on the cable at the pierce point to seal the penetration. I haven't seen this for many years; maybe I dreamed it.

You are right that there is no "shock" hazard with 12v systems but you can feel (or at least I can) a faint "tingle" above 16v. The human body's electrical potential is about 12v (we are after all electrochemical creatures) and that is why it is not felt. However, the high amperage can cause burns if you hold the copper conductors in a manner that causes a "dead short"to occur between your fingers.

In light of your question I am sure you would be interested in the other posts on this topic. The search engine will take you to the relevant posts if you use the search words; "pierce point", "connector", "wire nuts" or "contact" to name a few.