Existing installation

[HotConductor]

When performing a service call at a local convenience store I noticed the lever on the disco sw was broken off. The store has a 400a sgl. ph. and 400a 3 ph. grd. delta service. I lifted the door on the 400a sgl. ph. disco and noticed there was no egc run into the store. I checked the other 2 discos for the 3 ph. and same thing. Opened panels inside and confirmed no egc's.

The company has approved the upgrades to bring the services up to date in regards to disco replacement and grounding. My question is that there is a GEC running from each disco into the concrete sidewalk but I cannot see what they are connected to? Should I drive two new rods just in case?

 

[buddhakii]

What kind of coduit or wiring method i.e. emt, pvc, goes into the store? As far as the gec it probably goes to a ground rod. If the store has metal water pipe and bldg. steel you will have to use that, and I would go ahead and hook the old one back up but don't drive anymore rods.

 

[HotConductor]

What kind of coduit or wiring method i.e. emt, pvc, goes into the store? As far as the gec it probably goes to a ground rod. If the store has metal water pipe and bldg. steel you will have to use that, and I would go ahead and hook the old one back up but don't drive anymore rods.

Raceway into store is pvc; no building steel for GES

 

[mistermudd]

IMO if the existing GES or the condition of the GES cannot be verified, a new GES must be installed. Ground rods will corrode, I believe the are expected to last about 20 years depending on soil conditions. Near the ocean, I have pulled rotted off ground rods out of the ground myself. I think most inspectors would require an updated GES for any altered service, unless you can prove the existing complies with current code.

 

[Lcdrwalker]

A simple ground resistance test should tell you if the GECs are connected and in good shape. As far as the discos are concerned, have you looked into replacement parts? It might be a whole lot quicker, easier and cheaper.