Insulating a three-way joint

This is probably a pretty stupid question, but please bear with me, I'm pretty new at this stuff.

If I have a joint between (for example) a single wire and a single component lead, its easy enough to slip a piece of heat-shrink tubing over the joint to provide insulation. However, what does one do in the case of a three-way joint? I'm certainly not an expert in topology, but as far as I can tell its physically impossible to fit a tube (with two openings, one on each end) over a T-joint (with three wires coming out of it).

Using electrical tape of the sort one uses on house wiring doesn't seem very practical; it tends to be pretty bulky for the tight spaces typically found in electronic circuits, and also leaks adhesive and gets everything sticky over time.

Any suggestions would be appreciated. Thanks.

Rob Rothman

One of these.

3-way (11.6 KB)

Or you could use these:

I generally make something more like a "Y" instead of a "T" and just use one piece of heatshrink. (If it's components instead of wires, I'll also insulate the individual leads with heatshrink first, or if its' something like a resistor I might put a piece of clear heatshrink over the entire part.)

Or you could use these:

VERY "cheap" and VERY "small"


Or you could use these.

VERY "cheap" and VERY "small"

I know where I have seen those!

Up on a power pole, where the underground cable splits out to connect to the 33kV lines.

I'd be going with DVDdoug - there are very few situations where you require it to be physically structured as a "T", and certainly not where you are connecting flexible wires, so you just slip the heatshrink over one wire and after connecting, slip it back to cover the other two.

If it happens you want the joint to be waterproof, put a dob of hot melt glue over the joint and as the heatshrik compresses, the glue will extrude around and between the wires. For cable jointing, heatshrink is used which already contains a lining of the hot melt glue.

I am not sure that the commonly marketed PVC so-called "electrical" tape is actually permitted to be used in mains installations.

put a dob of hot melt glue over the joint and as the heatshrik

Or silicon glue.