User's Manual Part 1

12 OEMV Family Installation and Operation User Manual Rev 5B

Notice

Lightning Protection Notice

What is the hazard?

A lightning strike into the ground causes an increase in the earth's potential causing a high voltage

potential between the centre conductor and shield of the coax cable. Voltages directly applied onto the

centre conductor "roll off" and arrive after the shield pulse producing a high voltage potential between

the centre conductor and shield of the coax cable.

Hazard Impact

A lightning strike causes the ground potential in the area to rise to dangerous levels resulting in

personnel harm or destruction of electronic equipment in an unprotected environment. It also conducts

a portion of the strike energy down the inner conductor of the coax cable to the connected equipment.

Actions to Mitigate Lightning Hazards

1. Do not install the external antenna lines extra-building during a lightning storm.

2. It is not possible to avoid overvoltages 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. NovAtel recommends installing a secondary lightning protection device. The coaxial cable

entering the building is connected to protective ground through the primary and secondary

lightning protection.

Figure 1: Primary and Secondary Lightning Protection

Reference Description Reference Description

1 Primary Lightning Protection Device 4 OEMV Receiver

2 Secondary Lightning Protection Device 5 To Ground

3 External Antenna