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4 grounding and lightning protection, 1 equipment grounding, 2 internal grounding – Campbell Scientific PWS100 Present Weather Sensor User Manual

Page 36: 3 lightning rod

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Section 6. Installation

6-14

replacing the desiccant. This is of particular importance if using the sensor in
corrosive or salt laden atmospheres.

6.4 Grounding and Lightning Protection

6.4.1 Equipment Grounding

The present weather sensor must be properly grounded to protect it from
transients and secondary lightning discharges. The PWS100 has a ground lug
on the outside of its enclosure. This ground lug is connected to a tripod’s
grounding system via a 12 AWG copper wire. A 12 AWG copper wire is
included with Campbell Scientific’s tripods or towers.

To ground the system, first install the tripod’s grounding system as described
in the tripod or tower manual. The 12 AWG wire should be fastened to the
tripod or tower’s ground clamp. Route the 12 AWG wire from the clamp to the
PWS100 ground lug. Strip one inch of insulation from each end of the wire
and insert the end of wire into the ground lug and tighten.

6.4.2 Internal Grounding

The DSP enclosure of the unit and associated electronics are grounded through
the power cable assembly. The sensor components are in contact with each
other or have internal copper contacts.

6.4.3 Lightning Rod

Campbell Scientific suggests that a lightning rod is only fitted where there is
significant risk of lightning strike. During rainfall events water can accumulate
and shed from the rod and cause erroneous measurements. The rod itself can
also interfere with the passage of precipitation particles and ice accumulation
can exacerbate the situation.

If required, the lightning rod included with our tripods, UT10 Tower, or
UTGND Ground Kit should be used. The process of mounting the lightning
rod is described in our tripod and tower manuals.