The First electrical systems Did not have fuses?
I recently came across
this ceramic electrical distribution block. Today this
would be done with a sub-panel. Here you can see three cables feeding
two ceramic blocks. The enclosure was a handmade box lined with
what appears to be asbestos. Off of the two porcelain block
are 4 two wire circuit. All of the wiring was Knob and Tube style cloth covered
conductors. This home was built in the early part of 1900 when electricity was
new.
Here
is a close up picture of one of the blocks. There was an over current
protection built in. If you look closely you can see a thin wire that jumps
between the screws. This is an early attempt at fusing the circuit. The jumper wires
look to be made out of a metal other than copper. I think it is either lead or aluminum but cannot
be sure. This wire should be the weakest link in the
circuit and should blow before anything else in the circuit burnt up.
Fuses
were added to these ceramic blocks with standard Edison socket. The fuses
were standardized and rated at 15 or 20 amps for house circuits. It is hard to
believe that this old and very unsafe system was still in operation in 2012.
Once, I got the chance to hire the professional electricians from electrician-johannesburg.com , and I must admit that they are by far the best at Randburg.
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