BFW
Installation Guide
AN-30e & AN-50e Systems
1.7 Lightning
Protection
WARNING: The following notes are general recommendations for the system.
The wireless equipment should be installed by a qualified professional installer
and must follow local and national codes for electrical grounding and safety.
Failure to meet safety requirements and/or use of non-standard practices and
procedures could result in personal injury and damage to equipment. A direct
lightning strike may cause serious damage even if these guidelines are followed.
All outdoor wireless equipment is susceptible to lightning damage from a direct hit
or induced current from a near strike. Lightning protection and grounding practices
in local and national electrical codes serve to minimize equipment damage, service
outages, and serious injury. Reasons for lightning damage are summarized as:
- Poorly grounded tower/antenna sites that can conduct high lightning strike
energy into equipment.
- Lack of properly installed lightning protection equipment that can cause
equipment failures from lightning induced currents.
A lighting protection system provides a means by which the energy may enter
earth without passing through and damaging parts of a structure. A lightning
protection system does not prevent lightning from striking; it provides a means for
controlling it and preventing damage by providing a low resistance path for the
discharge of energy to travel safely to ground. Improperly grounded connections
are also a source of noise that can cause sensitive equipment to malfunction.
A good tower grounding system disperses most of the surge energy from a tower
strike away from the building and equipment. The remaining energy on the IF
cable shield and center conductor can be directed safely to ground by using a
lightning arrestor in series with the IF cable.
To limit the equipment damage due to a lightning strike, the following practices
are recommended for the wireless system:
- Provide direct grounding from the antenna mounting bracket, the radio and
antenna and the lightning arrestors to the same ground point at the base of the
tower or a ground bus on the building. Use the grounding screws on the antenna
bracket and the radio and antenna for terminating the ground wires.
- Install one RF lightning protector between the radio and antenna in series with
the RF cable.
- A lightning arrestor in series with the IF cable at the point of entry to the
building.
- Install a lightning arrestor in series with the IF cable at the transceiver on the
tower/mast.
- The AC wall outlet ground for the terminal must be connected to the same
grounding system as the radio and antenna lightning protectors.
- The ground connection on the back of the terminal should be connected to the
same ground for the building.
70-00042-01-02
Proprietary Redline Communications © 2005
August
2005
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