Swimbo wanted a new decor light switch. I switched off the circuit at the
breaker board. While changing the switch I touched the live to either the
neutral or ground with a pliers. There was a good flash with sparks. I did
not believe this. I put a meter across the live and ground (and neutral).
All volts were zero. I tested again by connecting the live to the neutral or
earth with the pliers. No effect this time.
So what gives? How can a residual voltage be contained in a circuit
disconnected at the breaker?
I completed replacing the switch, switched on the breaker and everything
When you went back to the breaker box, did you find an additional breaker in
the tripped position?
A neon light or meter between each combination of 2 wires is a good CYA
GFCI usually trip with much less drama at least hot or neutral WRT ground.
Hot to neutral may could tripped the breaker and left a GFCI still set.
I always introduce a intential short to check for such mistakes as
triopped wrong breaker or the dreaded this box contains 2 seperate live
circuits fed by 2 breakers.
better its a screwdrver frying than me flying across the
Hey its not funny to get hit bad, where a quick no spark assures your
not about to work in a hot box.
I have also worked on high voltage devices, better safe than sorry.
So you think my redundancy stuff is funny?
Think about that the next time something essential breaks in your home.
My best friend has had 2 washers and 2 dryers for over 30 years that I
have known him.
This summer I am drilling a water well in my back yard, for irrigation
and back up of city water. my hydra drill knock off is in place.
I think the point was the screwdriver was the "last ditch" check for safety.
I do use a voltage tester but I still also short the conductors if I intend
to actually touch them (as you know touching is not always necessary when
replacing a fixture). I also do this with DC circuits particularly with
I don't believe he was recommending it as a first line for tripping breakers
no the screwdriver short is the last test to make certain its dead.
every now and then you find a surprise, better the screwdriver than me!
lways turn breakers off, just occasionally you cant be certain you have
the right one
Many answers, for which I'm grateful. None of them applied except possibly
yours. On that 15 amp circuit there are a number of 4ft (80 watt)
fluorescents but collectively well below the 15 amp maximum. All these
lights were ON when I tripped the breaker. Could several starter circuits
store up some energy?
Many thanks for your suggestion.
is Joshua Putnam
Sometimes neon bulbs dont light, meters flake out but a nice
screwdriver to ground is 100% positive the circuit is dead.
one day I found a bad breaker that way it never tripped. would have
never known if I hadnt intentionally shorted test.......
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