IMKO TRIME-PICO 32, Manual

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Manual TRIME_PICO64-32 Version 2_0 2017-05-30
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9
Information on Lightning Protection of the
ENVIS Environmental Measurement System
(IMP-Bus, Datalogger and integrated Sensors)
9.1 Introduction
Lightning strikes can cause considerable and costly damage to unprotected electronics. The equipment is often
totally destroyed. A good number of users are not or only partially insured. Customers who have lightning pro-
tection insurance must comply with defined clauses regarding lightning and excess voltage. Insurance compa-
nies only cover the damage when compliance with the defined clauses has been proven. IMKO strongly rec-
ommends adequate lightning / excess voltage protection equipment for ENVIS environmental measurement
systems.
9.2 Excess voltage protection on 110/220V mains supply
Lightning strikes in proximity to high-voltage transmission lines can cause excess voltage in the mains power
supply which may result in damage of electronic components. Environmental measurement systems with
110/220V mains supply are at risk from this excess voltage. It may affect the whole system through the power
supply unit and the SDI12 datalogger or SM-23U). Excess voltage can even enter the measuring system through
the data acquisition computer’s mains power supply. An excess voltage protection is highly recommended for
all 110/220V devices connected to the ENVIS system
9.3 Protection of modem and telephone lines
Telephone lines are at risk from excess voltage. If a modem is connected to the measurement system the tele-
phone line should also be protected by a lightning protection module.
9.4 Excess voltage protection for network modules by "SM-Blitz"
Excess voltage caused by lightning strokes in close proximity to the environmental measurement test system
may enter the IMP-Bus transmission lines. Longer lines increase the risk of lightning strikes. Theoretically max-
imum protection is achieved by installation of a lightning protection module (SM-Blitz) in front of each SM-
Module. Lightning protection is not cheap but it is certainly worthwhile. A compromise should be found be-
tween costs and the maximum-affordable protection, i.e. interconnection of adjacent SM-Modules to lightning
protected groups.
9.5 Lightning protection on meteorological towers
SM-Modules installed on meteorological towers cannot be protected from lightning strikes. The field strength
resulting from the electromagnetic fields and the associated accumulated energy will cause damage to the
electronics. Two solutions to the problem:
Erect a higher lightning conductor close to the meteorological tower serving as a lightning conductor.
Install the measuring modules a number of metres away. Then all lines coming from the tower have to
be protected by lightning protection modules.
9.6 Installation instructions for SM BLITZ lightning protection modules
Basically, there are two potential sources of risk in the field of environmental measurement technology: trans-
mission lines and sensors or network devices. Lightning protection modules should always be installed at the
beginning and at the end of a circuit in order to protect the electronics from excess voltage (Attention: SM-Blitz
modules have a protected and an unprotected side).
The SM-BLITZ lightning protection module has to be grounded using a ground conductor with a wire cross-
section of at least 6 mm
2
screwed to the long side of the module. A 2-metre long grounding rod may serve as a
ground conductor. Grounding is optimal when the grounding rod is in direct contact with ground water.
9.7 Conclusion
Only limited protection against excess voltage is possible where natural phenomenon such as lightning strikes
are concerned. Direct lightning strikes may cause damage nevertheless.