ECN Forum Forums Code Related Discussion NEC & other Code issues alarm panel grounding

If there is any reference that tells the installer to install grounding per Article 250 of the NEC, we are pretty much limited to at least a #14 AWG- bare or green. I have never seen an instruction that said bond/ground to the nearest cold water pipe. I've been an inspector for 25 years and a contractor for 12 years prior to that. I am still learning so please fill me in.

the Gemini GEM_P3200 control panel/communicator instructions manual clearly spells out how they want the control panel to be grounded. min. size (for them anyway) is #16 AWG

Unfortunately many of these manufacturers are not familiar with proper grounding. The nearest cold water pipe can cause more problems than good, I have seen panels destroyed because of it during lightning storms.

The ground should be run in accordance with Art 250.

-Hal

Oh, let's open up a can of worms? I just think all of the opinions are great and why... I still stand by the fact that it is only a 12v system and offers no code noncompliance if the "ground" is connected to the water supply. Please give me a code article and not an opinion that says I am wrong.......( Must admit I do not like it either.)

I see a lot of total BS by electronics types who don't even understand how to protect their electronics and certainly don't have a clue about the NEC.
Again, refer to good old article 250!
If you drive another ground rod it SHALL be bonded to the ground electrode system.
There is no scenario where a "cold water pipe" is an acceptible ground for equipment.
There may be a piece of plastic in there somewhere.
In either above case (unbonded ground rod or "open" water pipe) your equipment will become the ground path that reconciles any ground shift difference making things worse than it would have been if you didn't "ground" it at all.
An article 250 ground will either be to ground it to the EGC in the circuit that supplies the equipment or to go to another point bonded to the building electrode.
In the computer biz they like going all the way back to the service disconnect so there is no intervening ground loop. I have never been convinced that ever fixed anything and I did it for 30 years.
You will be fine if you just go to the branch circuit EGC. It will certainly be code legal.

I am in for an education! So please tell me where it says in the code that a ground rod driven for only CATV or telephone systems needs to be bonded to the AC grounding system?

here's one
800.40(D) Bonding of Electrodes. A bonding jumper not smaller than 6 AWG copper or equivalent shall be connected between the communications grounding electrode and power grounding electrode system at the building or structure served where separate electrodes are used. Bonding together of all separate electrodes shall be permitted.
Exception: At mobile homes as covered in 800.41.
FPN No. 1:See 250.60 for use of air terminals (lightning rods).
FPN No. 2:Bonding together of all separate electrodes limits potential differences between them and between their associated wiring systems.

BTW FPN 2 is why the Telco or TV company should want to connect them all together.
"Ground" isn't zero volts and the actual voltage can vary quite a bit over a fairly small distance when you have a lightning strike. That difference can either be reconciled by heating up a #6 or by exploding a transistor ... your choice.
When we were fixing problems with blown LAN cards we were running fat bond wires along with them that tied the cases of the PCs together. Same concept. Give the shot a more attractive path. We also added ferrite beads to the signal cables to make that path less attractive but that is going beyond the scope of this thread.

In some areas consider the water pipe is the primary ground, the rod is secondary. (Due to soil conditions) It's a bit of a throw back to the days before PVC was acceptable for wide use in many areas of the country. Also not too long ago, ANY cold water pipe ANYWHERE was considered an acceptable ground. (not any more...) Recentley, we changed (locally?)to bonding gas lines at the nearest point past the meter. Point is things and attitudes toward the concept change....

Recently, during lunch watched a CATV contractor get chewed out by his boss for grounding his installation to a rod or water, instead of the main panel itself. ?????? (Didn't want to butt-in....)

shortcircuit, I think a simple jumper to a water (grounded), or equipment ground would be fine. This is an alarm panel, not a Service. The branch circuit is grounded right?

Now what is a "ferrite bead", and what purpose does it serve?

kentvw...I couldn't find anything in the code that restricts the connection of a ground wire to a water pipe for the fire alarm system I've described in my 2nd post.I think I must agree with what you said in your 3rd post, that the ground is to clear any static off the board or to look for ground faults on field wiring.Section 1-5.5.5 of the 1999 NFPA 72 says that "All systems shall test free of grounds".The panel that I saw required a ground to be connected to the circuit board and didn't require grounding of the steel enclosure. Manufacturers instructions seem to be the rule here.
Looking in the code I could not find anything specific to grounding of fire alarm panels.Artical 760 covers fire alarm circuits except for 760.9 which sends us to artical 250. Then there is 250.112(A) (I) which says CIRCUITS shall be grounded where required by part II or part VIII of article 250.
An exsample of another low voltage system we install that the steel parts are not grounded is a simple chime system...chime and door buttons are of steel construction sometimes.
e57...250.20(A) again refers to "circuits" and not equipment. The branch circuit that the transformer is pluged into is grounded.

shortcircuit