B
Bret Cahill
How many times can you flip a 30 Amp CB on and off before it wears
out? Say you as gentle as possible with the switch.
Bret Cahill
out? Say you as gentle as possible with the switch.
Bret Cahill
Different manufactures have different specs. What do you mean byHow many times can you flip a 30 Amp CB on and off before it wears
out? Say you as gentle as possible with the switch.
Bret Cahill
Some are designed to be used as light switches in retail stores &
factories, but others had warnings not to use them as a switch.
There is no "gentle" for a normal circuit breaker: the toggle action is
so strong that the contacts are going to thump hard no matter what.
What Mr. Terrell said about switch-rated breakers: there was a breaker
box at my dad's shop that had the circuit breakers turned on and off
every working day for the ten years that I worked there, and we never had
a problem (and I would know -- it would have been my job to swap the
breaker out).
Bret said:But you never hear of electricians advocating anyone going around
testing installed CBs for safety.
This is similar to the idiot light problem. Supposing the idiot light
has burned out?
How many times can you flip a 30 Amp CB on and off before it wears
out? Say you as gentle as possible with the switch.
Bret Cahill
Here in the UK AFAIK there doesn't seem to be any way to test them.
I had a
brocken socket to be replaced and couldn't find the breaker. We tried the
method of shorting the socket to earth to trip it. The wires just fused &
sat there live.
Here in the UK AFAIK there doesn't seem to be any way to test them. I
had a brocken socket to be replaced and couldn't find the breaker. We
tried the method of shorting the socket to earth to trip it. The wires
just fused & sat there live.
We eventually found the breaker at the other side of the store & had
to
replace with a derated one because the resistance of the circuit was
too high.
Ron
Last week my office's 30 years air con switch (single throw 20A )
breakdown, it was Mk brand , I manage to brough one balance stock from
a shop at thirty six dollar and it was make in UK during 2009. The
seller said you can save cost by using MCB as a switch and it is
very commom. BTW a china make unmark rating wall switch only cost one
dollar fifty cents only, sure not to use for air con.
Your wiring needs replacing, a short-circuit should blow even a breaker
of double that spec.
Or you can wait until the house burns down.....
If you read the above text, we had to derate the circuit from 32A to 16 AmpYour wiring needs replacing, a short-circuit should blow even a breaker
of double that spec.
That's the point, CB was FAULTY & not testable.Or you can wait until the house burns down.....
If you read the above text, we had to derate the circuit from 32A to 16 Amp
as the resistance of the circuit was too great for anything above a 16A
breaker to trip in the required time. Wiring otherwise tested OK.> Or youcan wait until the house burns down.....
That's the point, CB was FAULTY & not testable.
Thank you both for the insult to my father's abilities to wisely select
appropriate switches, and for once again discouraging me to answer your
questions.
Use switch-rated circuit breakers.
It seems like it was "over fused" or "over breakered" but how do you
know it was faulty if there was no test to determine if it was faulty?
They have a rated time/load curve. As the load increases the trip time isApparently you had _some_ test to determine if it was faulty.
Bret Cahill said:An acquaintence owned a nice small old house with a fuse panel,
probably 60 amps for the main. His insurance company refused to
insure it. The house was supposedly torched by a meth head and he
lost everything.