ECN Forum Forums Code Related Discussion NEC & other Code issues Alarm Panel Grounding

HLCbuild,

I agree with you when you say that "the ground that the manufacturer is requiring is not part of the Grounding Electrode System."

In any case, I believe that the alarm system manufacturer is simply asking that his box be reliably grounded. For some reason, the manufacturer trusts the metallic plumbing system more than the electrical system.

Are there known instances in the electrical industry when the integrity of the electrical system has been compromised?

If the ground bus in an electrical system opens up, no one may ever know about it. But if a water line breaks, it won't take long for someone to discover it.

The manufacturer assumes that the risk of the water line being modified over time are low enough for him to favour a ground connection to the plumbing system (at any distance from the entrance) over the electrical system.

For the electrician to go the extra distance in assuring that the connection is within 5 feet of the water entrance is allowing the electrician to lower the risk of the alarm box ground failing below the risk level that the alarm manufacturer is willing to take.

The instructions don't even say "metal water pipe" so it is clear the instruction is flawed. I haven't seen any metal in new construction here (electric or water) except the steel studs and they are not grounded either.
The code clearly says a metal water pipe is NOT a ground beyond 5' in a dwelling or any other place not "industrial and commercial buildings or structures where conditions of maintenance and supervision ensure that only qualified persons service the installation."

George Little, I started a discussion on this also...
https://www.electrical-contractor.net/ubb/Forum2/HTML/001625.html

I don't think the ground you are discussing is a equipment ground...

But if it is then...

I also would think physicle protection is a concern according to 250.120(C)

shortcircuit

I would like to know:
<OL TYPE=1>

[*] Does this equipment require to be BONDED to the GES,


[*] Does this equipment simply need to be Electrically BONDED to the system - the EGC,


[*] Is a supplimental Bonding Conductor required - which is Bonded to the GES at an "Effective Point", due to this equipment containing a MODEM, or similar device,


[*] If the instructions are just being as basic as possible - removing any liability on the Manufacturer's end.
</OL>

Semi-loaded questions, but not for trouble-starting purposes.

Have seen many FACPs with the noted "Ground Lugs", yet they all did not contain equipment which would warrant a bond to the GES.
They all used "Kind-Of Universal" enclosures, which resulted in all having the Ground Lugs - but only one actually needed to have a bond to the GES - the one with the event dialer (since the POTS circuit was dedicated to the FACP. the line pair was run directly from the TELCO's "PET" - and it is bonded to the GES, so does it really need to be bonded again?).

Have seen similar stuff on Alarm System Panels (Intrusion Alarms, etc.), Building Automation System Panels, and Audio Equipment for use in Commercial / Industrial locations.

Scott35

"by connecting to a water pipe"

The waterpipe is connected to the GEC.

The GEC is connected to the EGC.

The EGC is connected to the "ground" screw.

Good enough for an engineer.

Guys:
Within your 'basic' resi FA/BA panels, all I have seen is a terminal on the board within the enclosure marked "Earth Ground". None of these panels had a 'ground lug/screw' mounted to the enclosure.

These are resi, lite comm panels installed by 'alarm contractors'; some local, some national or regional.

To make it clearer, there's a board with electronic circuits & components, with a terminal strip for connection of the various circuits/devices, and one terminal is marked "Earth Ground" on the schematic. I don't know if this is the type of panel George is refering to or not.

John

Most of the systems I deal with just use it as a reference for the ground detector circuit. I've spent alot of time with one meter lead on ground and the other on signal circuit wires, hoping to find one a little closer to ground than others.
Joe

John- That is exactly the type of panel I am referring to and usually it will specify to connect the afore mentioned terminal on the terminal strip to a grounding electrode. Ask any electrician or inspector and they will tell you that the nearest water pipe is not necessarily a qualifying electrode. There was a time about 10-12 years ago when we could rely on the water piping in a home for a ground and we used to just go to the nearest pipe when we wanted to ground something. Times change, code change and now we can't just go to the nearest water pipe.

Another thing that has happened is we still have old school technicians who insist that grounding their panels invite surges and damage their boards. The manufacturers of the equipment specify that they ground to a grounding electrode.

George:
Copper water piping within a SFD is bonded thru the water meter to the street side (within 5') of the point of entry, and bonded thru the first means of disconnect with the grounding electrode (rods) or ufer in newer construction. Based on this scenario, a connection at the water pipe (copper) is acceptable.

Some new resi is using PEX water piping, and red/blue non-metalic piping, which will require going to the GEC at an accessable location.

Would you agree with both comments above??

John

John, you also have to look out for water softeners and whole house filters that may not be apparent when you look at the 5' "window" at the entry.
I still say the EGC in the circuit feeding the panel is the best bet. In most wood framed (non-Chicago) dwellings this *is* an IG.