Getting Strain Relief: TEC Fan Speed Control Wires Relax!

I finally souped up my TEC Fan speed control. If you compare the two images below, you’ll notice in the top photo the wires coming in and out of the fan speed control are “gland” type wire strain reliefs.  They work, but they have the tendency to focus all the bending stress at one point on the wire which eventually causes the stranded wires to break.

The old way:

Image result for the energy conservatory speed control

The fan speed control you buy today from Minneapolis has improved over the years internally, but still the same crappy wire strain relief bushings. If you have guys who abuse the wires, typically, the stranded wire eventually breaks inside the sheathing and eventually, the control needs re-wiring. It could be different.

There’s a better way.

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I bought a pair of wire strain reliefs for $5 at our local electronic supply store (A-1 Electronics) and installed them. I had to open up the holes with a step drill bit to move them apart yet closer to the centre line of the side panel so the nuts wouldn’t affect the ground wire and wouldn’t touch the box. I also had to drill out the new strain relief to take out 1mm of plastic in the throat to allow the old wire to be slid through.

With the new strain reliefs, I should be able to get a longer service life out of the speed control. To the good folks at TEC, these longer flexible wire strain reliefs won’t add much cost to your production; please consider it!