Many years ago, one of the manufacturing industries GB practised was Textile manufacturing. A company I worked for, for a VERY short period, dealt in the supply of new and used textile testing equipment. The manager/owner of this ‘firm’, him and two others, stated one day that what he didn’t know about electrics, a mate of his did. A used Lightbox appeared one day, basically a sheet of glass with an opal diffuser behind it and a couple of U shaped fluorescent tubes behind that, encased in a metal box. When a woven material is passed over it, any breaks in the warp or weft fibres (vertical and horizontal) is easily spotted.
UNFORTUNATELY, he took the decision to test this himself. On switch on, a very brief lightshow occurred and when WE enquired, HE had fitted a ‘Red’ plug onto the cable exiting the box. My immediate question was ‘Why should a fluorescent lamp be connected to a three phase supply?’
“Cos what came out of the box was a five core cable so it MUST require a three phase supply!”
On removing the back panel, it became quite apparent that at some time in a previous life, the original cable had been damaged, and some bright spark had replaced it with a piece of five core. The terminals INSIDE the box were clearly marked L N E
As stated earlier, a VERY brief period of employment there.
Regards Ian.