James,
     Two things are important for installers. The amp rating that is=20
printed on the handle.. Then there will be a label on the side and the=20
installer needs to make sure that it is UL certified. Whatever is on the=20
handle is the rated trip current. No other information is required by=20
the installer.
Thanks,
rich!

On 2/16/2015 6:37 PM, James Cameron wrote:
> I'm not surprised, but as I'm not in the US, it's only of academic
> interest.  As I said, I'm more interested in the physics and the
> specification of the parts.
>
> Is the label required to be different to that specification?  If so,
> that's a can of worms.
>
> On Mon, Feb 16, 2015 at 06:20:51PM -0600, Richard R. Pope wrote:
>> James,
>>       In the US the NEC is a legal requirement. Local codes must be at
>> least as restrictive as the NEC. Also if the wiring is not done to code
>> and the fire is caused by the poor wiring the insurance does not have to
>> pay. If someone is hurt or killed than the person who did the wiring is
>> now open to criminal and civil charges.
>>       I always consider the code as a starting point. As I said before I
>> wire all of the 15 amp 14 gauge circuits to 20 amp 12 gauge specs. I
>> also put in any where from 20 to 100% more circuits depending on the
>> life style of the home owner. In Wisconsin 100 amp panels are required.
>> I always install 200 amp or larger panels.
>> Thanks,
>> rich!
>>
>> On 2/16/2015 6:08 PM, James Cameron wrote:
>>> Agreed.
>>>
>>> I've always considered the critical specification of a circuit breaker
>>> to be the highest current it can hold and not trip, assuming standard
>>> test conditions ... such as voltage, temperature, humidity, magnetic
>>> fields, vibration, gravity, orientation, mounting, atmosphere content,
>>> and atmosphere pressure.
>>>
>>> What some provincial code then says about it, and how it requires any
>>> relabelling or use, is less interesting than the physics.  But if the
>>> label is required to be different to that specification, that's
>>> something to watch out for.
>>>
>>> On Mon, Feb 16, 2015 at 06:40:20PM -0500, Allen Mulvey wrote:
>>>> See:
>>>> http://ecmweb.com/basics/sizing-circuit-breaker
>>>>
>>>> "A CB is designed and evaluated to carry 100% of its rated
>>>> current for an indefinite period of time under standard test
>>>> conditions."
>>>>
>>>> The important part is "under standard test conditions." In
>>>> the real world the circuit breaker is likely to heat up
>>>> above "standard" test temperature. The 1996 NEC code
>>>> compensates for this by requiring you to use breakers rated
>>>> at least 20% higher than the anticipated load.
>>>>
>>>> Allen
>>>>

--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.