Mark, Proposing to bond electrical ground with tower ground at the tower is the opposite of what they are saying to do. I know, I know … we have done that pretty regularly in the past. We had a coupe towers that got total equipment losses a several different times… sometimes multiple times in one lightning season. All the potentials were within a couple ohms of each other … everywhere. We double, triple checked everything. Still got pounded.
At the expert’s sugg4estion of not bonding everything together at those 2 towers, we separated the grounds, and guess what… no more damages (almost 2 years now) And I understand the concept, but the grey area for me is… What about shielded Ethernet cables going up the tower… I mean your APs are grounded (450s, ePMPs, sectors to the tower, yet they would plug into your electronics at the bottom of the tower…seemingly linking the two systems together regardless of intent. I have lots of thoughts on that.. from shield kits on each Cat5 wire …to isolating antennas with rubber from the tower…. Which we have tried too, LOL. It all starts to get a bit cloudy in understanding… over the years we have had both paid and unpaid “experts” say…absolutely THIS is the way to do it, yet the next guy contradicts the former guy more frequently than makes me feel comfortable. Forrest, I hadn’t thought about backing the breaker size down to 15A…. that makes sense. I will definitely try that & the bigger ground cable to see if that helps at this site. From: Af [mailto:[email protected]] On Behalf Of Mark Radabaugh Sent: Wednesday, April 15, 2015 9:44 PM To: [email protected] Subject: Re: [AFMUG] Electrical - Grounding question - long run 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]<mailto:[email protected]>> wrote: 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 ☺ 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<http://www.pdmnet.com/> [email protected]<mailto:[email protected]>
