Originally Posted By: jtedesco This post was automatically imported from our archived forum.
THE RIGGED RECEPTACLE
Quote:
Randy Barnett, senior instructor, American Trainco, Englewood, Colo., sent me this photo of what was left of a receptacle that was installed in a large Midwest hospital.
The maintenance technician, who brought the receptacle to one of Barnett's training classes, said after he plugged in his vacuum cleaner and turned it on, the receptacle immediately exploded!
Investigation by the hospital's electric shop revealed that the receptacle had been improperly connected to a 480V circuit.
Luckily for him the vacuum wasn't on when he plugged into the receptacle.
You might ask yourself, How could a 120V receptacle be wired into a 480V system?
During a recent remodeling project at the hospital, a contract electrician needed some temporary 480V power, so he rigged a 120V receptacle to get the job done.
One can only wonder how he modified the plug he was using at the time. When asked about the situation, he said he simply forgot to disconnect it after he was done with his project.
Aside from the fact that the installation violates the Code's requirements that prohibit the use of equipment for a purpose for which it's neither suitable nor listed (110.3), the issue raises questions about whether any such electrician could be considered qualified.
Food for thought, watch out for mixed and crossed voltages that could result in a similar hazard.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
We had a similar situation when I was with IBM. Someone had wired a 5-15 to 277v.
The guy who plugged in the keypunch did have it on and it neatly melted the prongs off flush to the face of the plug.
I didn’t see the receptacle but I did see the wall afterward. There was a burn ring about a foot in diameter in the drywall. The guy had flash burns on his hand and skidmarks in his shorts.
Originally Posted By: phinsperger This post was automatically imported from our archived forum.
While on the subject of outlets in hospitals, I have noticed that in different hospitals the outlets were all upside down (with the ground at the top). This went both for regular outlets as well as isolated ground outlets. Anybody know why?
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Paul"
I believe that most Hospitals follow a recommendation found in their hospital standards, and that suggestion is UP for the ground pin, and in many cases for a good reasons when metal plates are used.
This subject has led to tears where grown men and women have wept trying to come up with a reasonable answer ... I will have some pictures and surprises during the Convention seminar I am scheduled to teach.
When they tracked down the problem with the outlet we had it turned out a "building electrician" (read:"janitor with a screwdriver") had tapped off the flourecent in the room for the new receptacle. I guess the grey/violet colors didn't spur any curiosity about what was going on the box. An 026 keypunch used a ferro-resonant power supply that tried to make that 277 be 120v and it looked like a bolted short.
The strange thing was it didn't hurt the keypunch. There was a blown fuse but that was the only problem ... beside the smoked plug cap.
Originally Posted By: phinsperger This post was automatically imported from our archived forum.
My understanding is the main focus of the arugments around receptical orientan is that if the plug is half falling out and most commonly on a downward angle;
1) Ground up helps to protect objects (including fingers) from touching the hot. (in a sideways install put the neutral up)
vs.
2) Ground down so you don't loose ground protection with hot still energized. (in a sideways install put the neutal down)
My question is has there ever actually been a study to determine which is more likely to prevent injury?
