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mm

On Thu, 28 Aug 2008 21:09:51 -0400, wrote:

On Thu, 28 Aug 2008 13:35:57 -0400, mm
wrote:

Didn't my Ademco burglar alarm come with instructions to install a
separate ground rod? It's connected to the board and not the power
supply, I think to prevent induced voltages from lightning from
ruining the alarm.

It would have been a lot easier to just hook up to the electrical
ground, but I did what the instructions said.

It's been 25 years but I still have the instructions. I will check
later.

Could they have learned anything new since then?

Sure, but are you saying that's the reason?

Is the requirement described in this thread that grounds be linked
together something that has arisen since 25 years ago?

It has been in the code for quite a while but buried out in seldom
read articles (Satellite and cable grounds were in the 800 articles
etc)
Things connected to the phone line were never really important until
people started buying phone equipment with 120v line cords on it
(modems, cordless phone or burglar alarms).
When they rewrote article 250 a couple cycles ago (the grounding
stuff) it got moved there.

Good to know. i'm in the middle of reinstalling my alarm, and I'm
redo the ground. thanks all.