Re: why ground an alarm panel.

[w_tom <w_tom1@xxxxxxxxxxx>]

  Wall wart creates an exception because the panel is no
longer directly connected to AC electric.  The primary reason
for doing this?  Alarm panel no longer need be submitted to UL
for expensive 'human safety' testing.  Since the alarm panel
is not longer directly connected, then it's exposed metal
parts (technically) need not be safety grounded.  Meanwhile,
good practice dictates that the safety ground be connected
anyway.  This for human safety.  And this also for reasons
provided by Robert Bass.

  Appreciate why so many appliances such as printer, laptop
computer, portable phone base station, etc all use power
bricks.  The power brick manufacturer gets the UL approval.
The appliance manufacturer creates many different products
that operate from a same (already approved) power brick.  No
appliance need be submitted for expensive and time consuming
UL testing - when designed, and when redesigned or modified.

autonut843 wrote:
> You said " Need I also cite the specific NEC requirements that connect
> that third prong to building's safety ground? "
> I think that was what he was looking for.  Nomen said,
> "Would you please cite a code reference for this?"
>
> You said "that third prong"
> but the standard non-X10 transformer that Ademco ships with has two
> screw terminals, neither of which connect to the ground prong.
>
> You said " If an appliance connects directly to AC power, then it must
> have a safety ground.  "
> but the typical alarm panel connects through a 'wall wart' AC
> transformer, not directly to AC power.
>
> You said "you apparently do not understand"
> You are correct, I do not understand, and it looks like others do not
> as well.  Hence the interest in seeing specific code references.
>
> Thanks, I am learning a lot through all this.