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0698-825 MD1xL / MD2xL - 06/2021
en
9.4 Equipotential bonding and earthing
!
WARNING
Explosion hazard by electrostatic discharge!
Risk of injury due to burns.
Pressure wave: fl ying parts can kill.
►
When using a drum pump to fi ll cans, drums or other portable or fi xed containers with fl ammable or
combustible liquids, both the container being pumped from and the container being pumped to must
be eff ectively BONDED and GROUNDED to prevent discharge of static electricity or sparks which could
cause explosion and death.
BONDING is the electrical interconnection between containers (such as drum and a receiving can). Bonding
must be completed before pumping begins.
GROUNDING is the electrical connection between a container and a „constant ground”. A „constant ground“
would be a metal pipe (water pipe) or rod in contact with the earth. An underground tank and piping
connected to it would be inherently grounded by nature of the installation.
Both BONDING and GROUNDING of containers of fl ammable liquids are required under U.S. Government
OSHA regulations and National Fire Protection Association Code 77, static electricity.
►
Before starting up, an equipotential bonding must be established between the pump, the container to
be emptied and the container to be fi lled (
→
Fig. 6).
►
Clamp the equipotential bonding cable (order no. 0204-994) to create an equipotential bonding between
the pump and the container to be emptied. For better conductivity, remove the paint and dirt from the
clamping points.
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Equipotential bond between the containers to be emptied and to be fi lled via a conductive substrate
(e.g. a conductive grating).
►
Ensure that a conductive transition between container and earthing potential is available.
Legend:
(1) Equipotential bonding wire, (2) ground wire,
(3) conductive hose, (4) conductive connection
from hose to hose connector, (5) Metal pump
tube with marking
II 1/2 G IIB T4 in Stain-
less steel or Hastelloy “C”, (6) explosion-proof
compressed air motor for zone 1, (7) nozzle,
(8) maintenance unit, (9) earth potential
Fig. 6
