Kinda off topic... Insurance of another type (avoidance) I often find locations where the grounds are hooked up to the tower ground which includes one or more ground rods… but what often goes unrealized is that the system is also grounded to another system through the utility company… and the tower and the utility company may not be properly bonded. So the lightning finds the big tower, and thinking it is a lightning rod… uses some of the path to ground through rods at the base of the tower but then also uses the path through the equipment to get to the power utility ground…. and pop goes the radio and router and such… Just don’t be that guy that connects the big lightening rod to the utility power ground through your router...
Your equipment should be surviving lightning strikes. Large towers can be struck multiple times per month and equipment can be on them for years without any damage at all. The fact that you lost equipment says that the strike was either direct to your equipment or you have a grounding issue that made your equipment a better path to ground. At some sites commercial radio engineers will even bring in a beaded cable from the tower and spread it across the floor to set all equipment on just to be sure that the ground panes are entirely bonded. The reason that equipment blows is that the difference in positive to negative current is out of range. When you get a lightning strike and things are not well bonded then you can have variances between grounds in the order of thousands of volts which will make your equipment pop like a fire cracker… if your ground is at 10,000v (relative to an average earth voltage) and your equipment is at 10,024v then the potential between them is 24v. It is like a bird setting on a high voltage line… somehow they don’t “feel” the high voltage… The trick to surviving a lightning strike is to bond all grounds well so ground is constant and then to have your power level referenced from that ground. This way if the earth ground or the tower ground or anything else has a sudden change then your equipment changes with it and remains relatively the same. After bonding your grounds properly so that you don’t end up with thousands of volts difference between two grounds like your power company ground and the tower that your equipment is mounted to… then you can install good surge equipment that will handle current overages in the event that you need it. The thing to keep in mind when grounding your equipment is that you don’t want your equipment to experience a situation like 0v for negative, 24v for positive and 50,000v for ground. If your equipment ground plane floats with a strike then it won’t even know that it experienced a surge. Just like a boat going over shallower and deeper water — who knew unless they had a fish finder running? During a strike, you don’t want a 5,000v on the utility ground while you have a 25,000v on the tower… If the cable between the two (or patch of earth between rods) won’t handle the surge or the impedance is too high then your equipment will possibly have two grounds with two very different power levels so the power will transfer from your shielded cable through your router chassis to the utility power until a something pops. The bottom line make the tower, earth, & utility power all the same and properly ground your equipment to that and you’ll survive most strikes perfectly fine. if you want some good reading google the terms: “copper.org lightning” they have some great write-ups with pictures of the good, bad and ugly. Sincerely, Joshaven Potter Google Hangouts: j...@g2wireless.co Cell & SMS: 1-517-607-9370 supp...@joshaven.com > On Dec 27, 2015, at 10:31 PM, Craig House <cr...@totalhighspeed.net> wrote: > > 2 in a year? We had 7 last night. > > Sent from my iPhone > > On Dec 27, 2015, at 21:22, Glen Waldrop <gwl...@cngwireless.net > <mailto:gwl...@cngwireless.net>> wrote: > >> We’ve had another lightning strike, at least the second one this year. >> >> I’ve got this feeling that our insurance company is probably going to start >> to get a little difficult in the near future. >> >> Who do you guys recommend? >> >> I’ve read about a few that cover everything, CPE, tower equipment, towers, >> labor, etc... I imagine those probably cost roughly what we bring in a year, >> but... >> >> Thanks guys. >> >>
