Proper grounding??

[chevyx92]

Here's the situation. An existing service feeds a strip mall. Poco feeds trough, taps are made in trough to feed each of the 6 meter bases. Below each meter base is a fused main disconnect. The trough is grounded by means of a cold water ground and a building steel ground. Some of the disconnects have a ground running from the trough, to the disconnect neutral bar, bonding it to the enclosure. The disconnects also have a ground running to a ground rod. Now, some of the disconnects have a separate cold water ground and building steel ground, as well as the ground rod. Shouldn't each disconnect have a separate cold water ground and building steel ground? Or is their installation of bringing the GEC to the trough, and then from there to the disconnect correct? What is the proper way this should be grounded? As some are grounded one way and others are grounded another way.

 

[tonyi]

All building steel, water pipes and rods together on one GEC, then tap that GEC for each service. The last guy in line doesn't need to be a tap, the GEC can go straight into that one.

This scehme is neat, tidy and goes in fast compared to trying to wrestle a GEC through all the discos.

 

[George Stolz]

• 250.24(A)(1) states that the GEC connection to the neutral "shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected at the service disconnecting means."

So, assuming this trough is accessible without busting POCO tags, this is a suitable location for this to occur. If not, then the grounding electrode system can't terminate in this trough, IMO.

From here on out, I will assume this trough is accessible, and continue.

Now, I am going to get a little weird, so I'm putting this in big print so that the folks who step in to cure my craziness can do their job.
Consider yourself warned.

I have been mulling this over, trying to think of the correct terms for these different conductors, and their respective functions, and have come to a wildly unthought-of (for me) conclusion regarding this stuff. I've been trying to concoct the perfect post based on solid references, and have been circling this a bit. Here's my unorthodox conclusion.

The conductors between the trough and the disconnect are EGC's, not grounding electrode tap conductors. I say this because the grounding point can occur anywhere on the load side of the lateral/drop, not solely in the service disconnect.

Therefore, all GEC's should run from the trough to the grounding electrodes. No "taps" running down to the disconnects are required.

Everything after the trough is concerned with bonding, not grounding. This bonding is accomplished with the system neutral, because it is on the line side of the disconnect(s).

Then, after the service disconnecting means, it's business as usual with separate neutrals and grounding conductors.