Receiver Card Notices
OEM7 SPAN Installation and Operation User Manual v14
21
Lightning Protection Installation and Grounding Procedure
What is the hazard?
A lightning strike into the ground causes an increase in the earth's potential which results in a high voltage poten-
tial between the center conductor and shield of the coaxial cable. This high voltage develops because the
voltage surge induced onto the center conductor lags in time behind the voltage surge induced onto the shield.
Hazard Impact
A lightning strike causes the ground potential in the area to rise to dangerous levels resulting in harm to personnel
or destruction of electronic equipment in an unprotected environment. It also conducts a portion of the strike
energy down the inner conductor of the coaxial cable to the connected equipment.
Only qualified personnel, such as electricians mandated by the governing body in the country of install-
ation, may install lightning protection devices.
Actions to Mitigate Lightning Hazards
1. Do not install antennas or antenna coaxial cables outside the building during a lightning storm.
2. It is not possible to avoid over voltages caused by lightning, but a lightning protection device may be used to
shunt a large portion of the transient energy to the building ground, reducing the over voltage condition as
quickly as possible.
3. Primary lightning protection must be provided by the operator/customer according to local building codes as
part of the extra building installation.
4. To ensure safe operation, a secondary lightning protection device must be used for in-building equipment
installations with external antennas. The following device has been approved by NovAtel Inc.:
Polyphaser - Surge Arrestor DGXZ+36NFNF-A
If this device is not chosen as the primary lightning protection device, the device chosen must:
l
Be UL listed (or equivalent) in the country of installation for lightning surge protection
l
The primary device must be capable of limiting an incoming surge to 10 kV
5. The shield of the coaxial cable entering the building should be connected at a grounding plate at the build-
ing's entrance. The lightning protection devices should have their chassis grounded to the same ground near
to the building's entrance.
6. The primary and secondary lightning protections should be as close to the building's entrance as possible.
Where feasible, mount onto the grounding plate itself (refer to the figure below).
