Friday, January 27, 2017

Shocked. I Tell You Shocked

Umatilla, FL

Yesterday, Libby complained that the RV lights and fan in the bathroom stopped working. Huh? That's strange. I checked it out and she was right (as usual). But an hour before I saw them working. Very strange.

I went to the breaker panel an verified that all breakers were reset.

The non-functioning part is a wall light switch with three switches, two for lights and one for the fan. I thumped the wall beside the switches. The lights flickered. OH NO VERY BAD! I thumped again, this time I not only saw a flicker, I heard an electrical arcing noise. VERY VERY VERY BAD! That is the kind of electrical problem that can lead to structure fires!!!

So, I shut off the breaker, and took things apart. I isolated it to one of the switches. It was not the kind of switch with screw terminals seen in housing. The wires disappeared into the inside. I opned it up. Horrors, instead of screw terminals, the wires were fastened with the type of connection used in vampire wire taps, sometimes seen in auto wiring as seen in this picture.

I've used connectors like that before in cars, to hook up low power things like tail lights.  But that was low risk 12V systems.  I also used them for the first 1 or 2 years on board Tarwathie, but I learned by experience that such connectors have very poor reliability.  I stopped using them on 12V systems many years ago.

I never dreamed that the safety codes would allow using that for 120V AC wiring.    But I must be wrong, because the manufacturer of my RV and the manufacturer of those light switches could not have gotten away with violating the law.

So it must be true that the National Electrical Code which assures us safe electrical practices allows huge differences between house and RV wiring of 120V circuits.  Oh my God.  I would have never guessed that.

I am tempted to replace all the outlets and switches in the whole RV to normal house standards.  The only thing that makes me hesitate is humility.  I'm an electrical engineer, not a licensed electrician.   If I set out as an amateur, I should expect unforeseen problems and mistakes.

Before doing anything hasty, I thought I would ask my blog readers for their opinions.   What do you say?

p.s. So what did I do in my bathroom?   I inspected the light switch carefully.  It was not faulty, so buying a new one would not help.  I stripped the insulation on the ends of the wires.  The conductors were not damaged, so there was no need to replace the wires.  So I reinstalled the wires in the original switch and the switch in the wall.  Sorry, but I forgot to take pictures, and I didn't think to take measurements to see if conventional house wires and an enclosure box would fit.

p.p.s.  I'm still trying to research more about the applicable safety codes.  My friend Jim Hardy is helping me.  Look for more on this subject in future posts.

UPDATE: Here are some pictures.   The switches are self-contained boxes, designed to fit in narrow spaces. In the bottom picture, you can see how the wires are connected with V-shaped clamps instead of screws.  Those clamps penetrate the insulation.  In the picture, I removed the insulation from the ends.

1 comment:

  1. Well Dick, ditching the solid copper would be the best route but not viable in your situation. As you know solid copper conductors are not well suited for installation where harmonic conditions are involved (i.e. industrial equipment, vehicles, RV's, Marine, etc...). Being 120 vac I would change out all the switches in the RV (and check the outlets) to a compatible screw terminal type and ensure you have GFIC breakers installed for your wet areas. Most local codes are related to new installations not home owner repairs.


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