James,
     The breakers sold and used in the US are rated at 80% continuous=20
current of what is stamped on the handle. This is required by UL labs=20
and the NEC. So if the handle has a 20 stamped on it the instantaneous=20
trip current is 20 amps and the maximum continuous holding current is 16=20
amps. This is the law here. You can download the datasheet for whatever=20
model that you want more info on. To us installers all we care about is=20
what is the number on the handle, is it an arc-fault breaker, (this was=20
required as of 2013 in the US), and is it UL listed. Nothing else=20
matters to us. I have never done any additional research beyond that.
Thanks,
rich!

On 2/16/2015 8:01 PM, James Cameron wrote:
> Is the rated holding current printed anywhere on the breaker?
>
> As previously quoted by Allen, "A CB is designed and evaluated to
> carry 100% of its rated current for an indefinite period of time under
> standard test conditions."
>
> So what is the technical difference between a rated holding current
> and a rated trip current?
>
> On Mon, Feb 16, 2015 at 06:45:04PM -0600, Richard R. Pope wrote:
>> James,
>>       Two things are important for installers. The amp rating that is
>> printed on the handle.. Then there will be a label on the side and the
>> installer needs to make sure that it is UL certified. Whatever is on the
>> handle is the rated trip current. No other information is required by
>> 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 a=
t
>>>> least as restrictive as the NEC. Also if the wiring is not done to cod=
e
>>>> 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 i=
s
>>>> now open to criminal and civil charges.
>>>>        I always consider the code as a starting point. As I said befor=
e 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.
>>>>>

--=20
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