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The main functions of gas pressure control and measurement spread power supply and information technology systems
systems are to monitor and calculate gas volumes, automati- at lower costs. The IEC 62305-4 (EN 62305-4) standard de-
cally operate the stations by means of volume and condition- scribes measures for protecting electronic systems.
oriented connection and disconnection of measurement and
control systems as well as volume control and monitoring of Risk analysis of the gas pressure control and
the gas transport between the distribution network opera- measurement system
tors. The protection of the structure and technical equipment
against the effects of a lightning strike and personal protec-
Certain functional units that are connected to the power tion must be taken into account right from the design stage.
supply system are subject to the stipulations of section 3 For this reason, adequate protection goals are define togeth-
of the German Ordinance on Industrial Safety and Health er with the operator before performing a risk analysis.
(BetrSichV). The operator must ensure compliance with these
stipulations which apply to e.g. systems in potentially ex- In our example, the protection goals would be:
plosive atmospheres whose components are covered by the ¨ Fire and explosion protection
94/9/EC directive, e.g. the installation of devices complying
with the requirements of the 94/9/EC directive, their installa- ¨ Personal protection
tion according to the state of the art, inspection and testing ¨ Protection of the electronics of systems with high avail-
prior to commissioning and recurrent testing by a competent ability
expert under the responsibility of the company.
The German Technical Rules on Operational Safety (TRBS) At first, the loss factors according to IEC 62305 (EN 62305),
specify in greater detail the fundamental requirements of the the required availability and the risk are determined. This
German BetrSichV to be observed in this context. The Ger- leads to the following loss factors:
man DVGW Code of Practise G 491 describes the require-
ments for electrical and non-electrical explosion protection
of gas pressure control and measurement systems, referring
to the existing TRBS as a source of information.
air-termination system r = 30 m
Risk analysis – Determination of the current state + HVI Conductor
The current state of the system must be determined in a site
survey. To this end, the structural conditions, existing docu- stainless steel chimney
ments and possible requirements of property insurers must s
be observed. blowout

A risk analysis is performed in cooperation with the operator
to define the protection measures required to prevent the
destructive effects of lightning strikes and surges. To this end,
designers use approved regulations that allow to design a
complete protection concept. EBB
The IEC 62305 (EN 62305) standard is a reliable design basis
for future-oriented lightning protection systems. This stand- MEB
ard is used to design, install, inspect and maintain lightning
protection systems for structures.
The risk of a lightning strike and the necessity of a lightning
protection system for an object to be protected are determined Components P Part No. .
art No
Components
according to IEC 62305-1 (EN 62305-1) and IEC 62305-2
Roof conductor holder with angled brace
(EN 62305-2). Technically and economically optimal pro- Roof conductor holder with angled brace 202 830
202 830
for HVI Conductor
tection measures are selected depending on the risk. The for HVI Conductor
Wall-mounted conductor holder for HVI
IEC 62305-3 (EN 62305-3) and IEC 62305-4 (EN 62305-4) W all-mounted conductor holder for 275 229
275 229
HVI Conductor
standards describe how to implement the protection meas- Conductor
ures determined. Thus, the IEC 62305 (EN 62305) standard Earthing busbar (2 x 472 109
472 109
Earthing busbar (2x2 terminals)2 terminals)
is a solid basis for operators and designers. This standard
makes it easier to take further protection measures for wide- Figure 9.33.1 Isolated external lightning protection system for a
gable roof
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