Re: why ground an alarm panel.

[w_tom <w_tom1@xxxxxxxxxxx>]

  Your question was answered accurately.  Please read before
posting:
> Numerous codes apply including UL, NEC, and maybe some from
> your utility.  However all those codes come down to one
> fundamental point - a point based upon the purpose of all those
> codes:
>> If it has conductive parts that a human can touch, then
>> somehow those parts must connect to building's safety
>> ground system.

  If you need a specific code, then visit UL. Meanwhile with
minimal technical knowledge, that point is well understood.
If the appliance directly connected to AC mains has exposed
metal, then it must have a safety ground.  All those other
codes conspire to demand that exposed conductive material on
an appliance connect to the building's safety ground.

  Need I also cite the specific NEC requirements that connect
that third prong to building's safety ground?  If I do, then
you either have no business wiring anything electrical, or you
only want to argue.  If you don't know of NEC code that
connects safety ground prong to building's safety ground, then
you have no business wiring electrical items.

  Meanwhile, a whole chapter from the NEC is called Article
250. I am not going to quote the so many relevant sentences
for obvious reasons.

  An electrically conductive surface on an AC appliance must
have a connection to the building's safety ground system.  An
exception to safety grounds was once hyped with a sales
expression, "Double Insulated".  A term requiring minimal
electrical knowledge of those various requirements that
otherwise required a direct connection to the building's
safety ground.

  If an appliance connects directly to AC power, then it must
have a safety ground.  Some use methods of getting around UL
requirements that are beyond the scope of this discussion.
Furthermore you apparently do not understand the scope of the
expression "UL, NEC, and maybe some from your utility" which
would explain why a quote from the NEC is irrelevant and
misguided.  By understanding the meaning of "UL, NEC, and
maybe some from your utility", then you would have never asked
for an NEC quote.

Nomen Nescio wrote:
> You haven't answered my question.
>
> Please cite an NEC code reference that requires grounding of an
> enclosure that only contains Class 2 or power-limited fire alarm
> circuits.  I don't give a damn what you think is "intuitively
> obvious."  Cite a code reference to support your position!