The MapleNet 6 Point Grounding System:

1. Provide an attachment point for the lightning or static discharge
2. Provide a safe path to ground
3. Dissipate the energy into a low impedance ground system
4. Bond all ground points together
5. Protect AC power with UPS/Battery Backup
6. Protect all data lines with surge protectors or optical isolation

Capture the lightning strike to a known and safe attachment point. This is usually an air terminal which is a copper rod with a very fine point that is extended on the tower above all antennas. This air terminal is bonded to the tower structure so that a direct lightning strike is encouraged to hit the air terminal and transfer the energy directly to the tower rather than through the antennas or cables. The energy is safely conveyed to ground through the tower itself. All coaxial cables are grounded to the tower at 75 foot intervals to insure that the tower and the cables are on the same voltage potential at all times. This also insures that any lightning energy that may get into the antenna and cable system will be grounded out to the low impedance tower grounding system.
Dissipate the energy into a low impedance grounding system. A typical MapleNet grounding system involves a ground ring placed at least 8’ outside the tower foundation and completely surrounding the tower foundation and equipment compound. The ground ring typically is buried below the frost line and all connections are exothermically welded rather than mechanical clamp connectors. The photo at right shows the in-line coaxial lightning arrestors and grounding bus bar at the base of the tower.
In addition to grounding the cable every 75’ vertically along the tower it is grounded at the base of the tower and at the building entrance
The Solid # 2 tinned copper wire in the photo is exothermically welded to the ground rod to create a continuous ground ring around the tower.
Exothermically welded #2 solid tinned copper wire to tower leg. This wire connects each leg to the ground ring.
The photo shows the remnants of the trench where the tower ground ring was installed. The green lines show the ground ring which has ground rods spaced every 16’ around the perimeter of the foundation. Each tower leg is bonded to the ground ring as well as the power feeder lines coming into the tower and all coaxial cables running up the tower. All connections where possible are exothermically welded. Other connections are compression lug and bolted tight.
Trenching the grounding ring.
All data lines must be protected either using Ethernet surge protectors or in mission critical applications by using fiber optic transceivers.