Biogas Safety first!

Specific requirements
in installation rooms exposed to gas (CHP unit,
gas purification, etc.)
Closing of gate valves so that substrate cannot
flow back into the feed system (e.g. pre-digester
pit, animal shed)
External feed facilities must be capable of being
shut off in the event of system breakdown to
prevent overfilling
A drop in the fill level must not lead to an uncontrolled
escape of gas, for example from the feed
system
The latest applicable standard for electrical equipment
of machines and the equivalent for safety-related
parts of control systems must be used for the
design of safety-related parts of the control system.
A hazard and risk analysis must be performed in accordance
with national guidelines.
Organisational protective measures
The requirements for safe functioning of instrumentation
and control (I&C) equipment with a safety
function must be established, determined and documented
on the basis of a hazard assessment.
17. Requirements for electrical engineering
17.1. Equipotential bonding
The relevant national regulations apply to all electrical
installations and switchgear.
In order to prevent the creation of potential differences,
all electrically conductive plant parts must
be connected to each other and to the protective
conductor and the potential equalisation.
!
TIP
It is always advisable to have the electrical
installations checked by a qualified electrician
prior to commissioning and at regular
intervals. For details refer to the section on
inspections and tests.
Technical protective measures
The following protective measures must be taken in
order to prevent potential differences:
Cable entries and glands must be suitable for the
respective ignition protection types. In addition,
electrical installations must be designed and
electrical equipment assembled and installed so
as to ensure easy access for inspection, testing
and maintenance.
Electric cables and leads must be laid separately
from pipes, with the exception of electric trace
heating systems. Electrical installations must be
designed to restrict the effects of electromagnetic
fields to a safe level.
Dangerous accumulations of electrically conductive
dusts in or on electrical equipment must
be avoided, for example by means of enhanced
dustproofness for the equipment.
Suitable measures must be taken to prevent the
entry of ignition sources into hazardous areas
via cables and leads. Cables and leads should
be laid without interruptions in hazardous areas.
If this is not possible, the connections must be
made in enclosures with a protection type appropriate
to the zone or they must be secured by
means of appropriate junction boxes.
Discharges of static electricity must be avoided
if they are capable of being effective ignition
sources.
High charge-generating processes give rise
to such high charge levels that spontaneous
ignition-inducing discharges may occur. The
use of objects or equipment made of insulating
materials in hazardous areas should be avoided.
If objects or equipment made of conductive or
dissipative materials cannot be used, measures
must be taken to prevent dangerous charging.
!
TIP
Possible measures include conductive or
dissipative coatings, conductive threads
in textiles, limitation of surface areas or reliably
effective organisational measures.
49