Danger Danger – Bus Plugs
Or sorry not me, I have something planned later tonight
By Dan Marchewka
Huh?
Dangerous Waters, Aguas Peligrosas
A famous actor once said, (I forgot his name) “Do you feel lucky today, Well do you, punk?”
Those allusions may be a little extreme, but are they really?
Older electricians (there are still some around) remember the days of open Frankenstein switches (there are still some in service today), those fabled switches of yore, who take their namesake from Frankenstein movies as electrodes strode across open air circuits and voltage danced freely around the laboratory like gypsies at a wine tasting festival. The Frankenstein switch, open knife blade switches typically mounted on slate boards, were thrown in live by hand. In those days PPE (Personal Protective Equipment) were not yet a distinct part of worker safety. In fact, back then, worker safety was not yet considered part of worker safety.
Where is all this leading? Hang on. Meet the door operated bus plug, a second cousin to the floor operated bus plug. While these two little devices are of the same family and serve the same purpose, the former is the troubled nephew of the clan and is not (skeptics are you listening) for the faint of heart. Older door operated bus plugs such as the Square D Safeflex, for example, (there are others from other manufactures) were designed such that the door, as in metal door, as in bare metal door handle, were part of the bus plug’s operating mechanism. Now here’s where it gets good. The person opening the bus plug door, say to change out a fuse, balancing himself, (not herself, there weren’t as many women electricians around back then) up high on the Scizzors lift, believing the load is off, (he knows the end machine has been turned off) was most often not fully appreciative of the surprise he was about to engender. Opening the door, unless he was made of stone, would reveal a startling revelation: A gee-wiz moment, (people don’t say gee-wiz anymore do they?) Ok a holy *hit moment. As anyone who’s done it can testify, opening the door of a door operated bus plug is like prom night but without the tuxedo –you never know what awaits you. The movable contacts of the bus plug switch are part of the bus plug door. While load may be off the circuit the voltage is not. Opening the door breaks the circuit. So let the word go out to friend and foe alike, the torch has been passed to a new generation of Americans. When conducting this high wire circuit interrupting act be careful to identify the type of bus plug and always wear your appropriate protective equipment.
For you older electricians I know what you are thinking, it was the fun part of the job. Fair enough.
Be safe….and remember, bus plugs are “Dangerfields”…they deserve your respect.