We have a 50ft tower on a ridge with 4 ePmP 1000 5ghz access points and a backhaul to another tower. They want to run a horizontal pole 115KV line really close to the tower. There is room to move it away about 20ft without them having to take it off a steep drop. They are saying the lines will only be 40ft off the ground. I have another tower that has been just fine next to a 200KV line for years but the lines are at least 40 ft above the top of our little 40ft tower and about 100ft away. I think this is too close. Suggestions please.
We have a 60 foot tower about 40 feet from power lines of about the same height running 2.4, 5 Ghz, and 900 with no issues. Everything is very well grounded. Soare you saying they will only be 20 feet away?
They agreed to be 100 ft away. At that distance our 50ft tower will be 22.5 ft below the lowest power cable. Should be ok. Our tower is well grounded. I just get concerned about some of the newer electronics being more sensitive to static in the air during rain and snow.
Power lines do not cause static in the air, in fact they remove it plus the “skywire” (OPG) will also help protect your equipment from ESD events.
What I would be worried about is the type of service they are going to run? HVDC is a no go, but 3phase AC is ok. HVDC creates a constant magnetic field that will cause issues but 3phase AC fields have a canceling effect. It is not a complete canceling but it is manageable.
Hi Douglas,
What kind of issues can a constant magnetic field generate? We are surrounded by the natural Earth’s magnetic field, which is perhaps weaker than that of a HVDC line. Does this make a difference?
The earths magnetic feild density is not static and is between 30 and 60 microteslas, your average hvdc can have a static feild of a few hundred milli-teslas. This is strong enough to distort your RF paths and cause corruption of the signal. You can see this effect with a compass if you walk towards a hvdc line. It will deflect either away from or towards the lines depending on the polarity of the lines.
Balanced AC lines (3phase) generally cause a magnetic void which neither helps or hinders unless your shooting over a sub-station which a whole new group of physics needs to be understood.
As long as your frequency is not a multiple of the AC system frequency or its 3rd order harmonic you wont have an issue except with what they pay you for the right of way.