James, Allen,
     We have to be careful here. What I am talking about is the rated=20
trip current. A circuit breaker with 20 amps on the handle which is the=20
rated trip current will trip under two different conditions. The first=20
condition is if a sudden current of 20 amps or more is drawn by the=20
circuit. The second is if a current of 80% of the rated trip current,=20
which is 16 amps for a 20 amp breaker is drawn for an extended time=20
period. This has nothing to do with what the contacts are rated at. This=20
only deals with the circuit conditions.
     You can go to the manufacturers website and find out what all of=20
the ratings are. Yes, if the voltage were to go very high for some=20
reason the breaker would trip if the fuse on the primary side of the=20
transformer didn't blow first. In the US we have two different voltages=20
available in most of our homes. It is single phase 120 and 240 volts.
Thanks,
rich!

On 2/16/2015 4:25 PM, Allen Mulvey wrote:
> If the breaker pops at a higher current the wire will get
> hotter than it should and could cause a fire. I agree all
> components should be able to handle at least 20% more than
> required but this cannot apply to the point where breakers
> pop. The breaker contacts, etc. should be able to handle
> more, you want it to pop before it self destructs.
>
> Allen
>
>> -----Original Message-----
>> From: piclist-bounces@mit.edu [mailto:piclist-
>> bounces@mit.edu] On Behalf Of James Cameron
>> Sent: Monday, February 16, 2015 5:00 PM
>> To: Microcontroller discussion list - Public.
>> Subject: Re: [EE] Insulation testing
>>
>> My ambiguity detector fired ...
>>
>> On Mon, Feb 16, 2015 at 03:36:48PM -0600, Richard R. Pope
>> wrote:
>>> Robert,
>>>       It is ok for a breaker to trip at less than what
> the NEC
>>> specifies but not at a higher current.
>> I'd really want a breaker to trip at a higher current than
> it is
>> specified for.
>>
>> --
>> James Cameron
>> http://quozl.linux.org.au/
>> --
>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list
>> archive
>> View/change your membership options at
>> http://mailman.mit.edu/mailman/listinfo/piclist

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