Re: Carbon dioxide bike tyre inflation (was Re: That was dumb..)

On Mon, 19 Nov 2007 17:36:35 +0000 (UTC), brian@xxxxxxxxxxxxxxxx (Brian
Kantor) wrote:

Chris Suslowicz <chris+news@xxxxxxxxxxxxx> wrote:
Miniature Circuit Breakers see the rapid rise in current draw and
promptly trip.

Are you allowed time-delay breakers that will not trip on short-duration
moderate overloads but still pop fast on massive surges?

You're allowed whatever you want, at least on our side of the small pond
(and we are after all harmonising these things in the EU..)

I think most household breakers in the USA have a delay; although
I no longer use incandescent lamps, I can't recall ever popping a
breaker when a lamp blew out.

A standard fuse here would be equipped with a "D" characteristic, which
means IIRC that it pops (essentailly) instantaneously at 20x Inom.. ah,
right, 10-20x Inom.

A standard .nl breaker has two segments, a heat-operated one that always
works the same, tripping on a curve, between 1 and 20 minutes at 1.5x
Inom, 5 and 20 seconds at 3x Inom, and stuff in between that and not
tripping at all at 1x Inom. There's also an electromagnetically operated
one that trips at a certain overcurrent, regardless of time. It's the
latter that responds to very short duration shorts (I wonder if that's
what the americans mean by AFI? Maybe their regular breakers don't have
one?).

Standard breakers are B-kar, which is instant trip at 3-5x Inom, and C-kar
and D-kar are available at between 5-10x Inom and 10-20 respectively. I
don't actually have any breakers, though, just a couple of GFCIs and a
bunch of D-kar fuses. Those never trip on a broken bulb. Never heard
anybody complain about B-kar breakers either, though.

Jasper
.

Relevant Pages

  • Re: Electric Problem or overloading the circuit
    ... tripping will not necessarily trip the other breaker. ... Breakers are "trip free" ... Handle-tied breakers are necessarily "common disconnect". ...
    (alt.home.repair)
  • Re: Outlets went out but no breaker is tripped
    ... None of the breakers are tripped. ... Maybe with the fridge on a separate line, the pump won't trip. ... don't think the fishtank pump motor is big enough to matter, ... abundance of water and humidity involved. ...
    (alt.home.repair)
  • Re: What to call & Where to get Siemens breaker "lever joiners"
    ... the outer two of the levers in this kind of Siemens breaker. ... The linked breaker comes with a tie for the center 2 breakers ... trip no matter what the handle is doing. ...
    (alt.home.repair)
  • Re: Federal Pacific breakers
    ... weakens at least one of the wire ends. ... like an inadequate test of a 20A breaker -- you still don't know if it ... will trip at 25A as expected. ... My understanding of fuses and breakers is that they typically will run ...
    (alt.home.repair)
  • Re: Conductor rail risks
    ... How much does it take to trip the breakers? ... so that a current marginally in excess of the setting will not cause a trip. ... On the Southern, there was traditionally no communication between the breakers at each end of the section, so the breakers have to be set to detect a fault at the distant substation, so that the breakers at each end of the section would always trip. ... The principle of the TCR is that they are located at the mid-point of the electrical section and the breaker only needs to detect a fault between it and the TCR. ...
    (uk.railway)