You should have had a large copper (I forget the exact size. I thought 4 or larger, but someone suggested 0/2.) among tower, equipment and electrical ground.
----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com ----- Original Message ----- From: "Josh Baird" <[email protected]> To: [email protected] Sent: Thursday, April 16, 2015 7:16:55 AM Subject: Re: [AFMUG] Electrical - Grounding question - long run We recently had a site where an electrician installed a panel and his own ground (rod) for the electrical/AC ground. We then installed our equipment at the bottom of the tower and bonded everything in the cabinet to the tower ground. This site took a pretty bad strike and it was my understanding that this may have happened because the surge traveled through our equipment and out of the AC/electrical ground since it was the path of least resistance. I am admittedly stupid when it comes to grounding, so, was this actually the proper way to ground this site? Josh On Wed, Apr 15, 2015 at 9:44 PM, Mark Radabaugh < [email protected] > wrote: For electrical service purposes the ground wire you have is fine. The tower itself obviously needs to be well grounded. Where is your equipment? I'm assuming it's at the tower since you talk about driving the battery charger. All of the equipment at the tower needs to be bonded together with the tower ground and the electrical ground. A good 120V surge suppressor at the tower, grounded to the tower ground, will help avoid damage from coming in over the power lines. You are not trying to protect equipment back at the breaker panel. The ground wire size back to the panel is pretty irrelevant as long as it can carry enough current to trip the breaker in a short circuit condition. Other than that it doesn't serve much purpose. Mark On Apr 15, 2015, at 3:41 PM, Paul McCall < [email protected] > wrote: <blockquote> In my continued disposition of acknowledging that I am not a electrical grounding expert, I lay out this scenario for review, a new tower we just built. We installed a new tower, approximately 200ft. from the service panel that feeds it. We will be on our own breaker (kinda irrelevant here). In the past, we had run 10 gauge wire (x3) out to the tower with 110vac. Voltage drop is relatively negligible, certainly within the bounds of working properly to drive our 24v charger for the battery array. I was told, by a grounding “expert” that all my equipment electrical grounds need to homerun to a bus bar that ride the ground back to the service panel directly, that nothing else is acceptable. AND, and this is the big part… that I needed to seriously upgrade the 200ft. ground wire only that rides back to the panel to something significantly bigger. How much bigger I am not sure. So, I figured I would ask the crowd for an answer J Thanks! Paul McCall, Pres. PDMNet / Florida Broadband 658 Old Dixie Highway Vero Beach, FL 32962 772-564-6800 office 772-473-0352 cell www.pdmnet.com [email protected] </blockquote>
