K8MHZ
Senior Member
- Occupation
- Electrician
I hooked up an electric space heater for a business owner that was penny wise and dollar foolish.
The unit was a 440 three phase resistance heater that required to be fed with #6. Owner had piles of old nasty #6 he pulled from somewhere else and wanted me to use it. I told him that I would rather not, but since I was getting paid by the hour I just made the attempt.
The stuff was so old it was brittle and took me and a bull rider to pull in the 27 foot run, one time bull rider boy actually pulled my pipe off the wall. We did get it in, though. I think I had four hours into it and bully boy had not quite two.
So me and Mr. Owner are standing under the heater basking in it's warmth when the explosion occurred. It seems a strand of wire made it's way through the old insulation and made contact with my solidly grounded conduit and blew a hole clean through the EMT. Sparks flew around us as we were not far from the run. Mr. Owner became weightless for a micro-second and may have wet himself. 277 to ground makes a pretty big boom.
This made my case to use new wire. I cut out the EMT along with the wire inside and use it in my radio classes to illustrate what electricity can do if left to it's own devices. After I got the wire and burnt pipe out, I pushed in the new #6 unassisted in about minute or so.
I also use the nifty teaching tool when the powers that be decide they want to use left over wiring and or equipment.
The unit was a 440 three phase resistance heater that required to be fed with #6. Owner had piles of old nasty #6 he pulled from somewhere else and wanted me to use it. I told him that I would rather not, but since I was getting paid by the hour I just made the attempt.
The stuff was so old it was brittle and took me and a bull rider to pull in the 27 foot run, one time bull rider boy actually pulled my pipe off the wall. We did get it in, though. I think I had four hours into it and bully boy had not quite two.
So me and Mr. Owner are standing under the heater basking in it's warmth when the explosion occurred. It seems a strand of wire made it's way through the old insulation and made contact with my solidly grounded conduit and blew a hole clean through the EMT. Sparks flew around us as we were not far from the run. Mr. Owner became weightless for a micro-second and may have wet himself. 277 to ground makes a pretty big boom.
This made my case to use new wire. I cut out the EMT along with the wire inside and use it in my radio classes to illustrate what electricity can do if left to it's own devices. After I got the wire and burnt pipe out, I pushed in the new #6 unassisted in about minute or so.
I also use the nifty teaching tool when the powers that be decide they want to use left over wiring and or equipment.
