4.1 Equipotential bonding
If the motors are operated together with the pump, comprehensive, clear equipotential
bonding is essential (earthing).
1
Ω
4
Fig. 1: Earthing in hazardous locations
>
Connect the equipotential bonding conductor (earth wire) to the designated screw
on the explosion-proof motor and pump.
>
If the connection between the motor and pump already provides a conductive
path (for pumps for flammable liquids), one of the equipotential bonding conductors
may be dispensed with.
>
Mains connection (2) is to be established via an explosion-proof connector, an explo-
sion-proof terminal box or outside of the hazardous area.
>
Only use hose lines (3) with conductive hose unions (see TRbF 50 Annex B.
Ω
6
(R < 10
).
>
Remove paint and dirt from all connection points of equipotential bonding conductors
and transition points of the containers to the electrically conductive base ground to
ensure good conductivity.
The electrically conductive base ground (4) must be an integral part of the equipotential
bonding system.
If a conductive base ground is not available, equipotential bonding conductors must be
connected to all barrels and containers.
Note
Explosion protection at the connection point is not necessary if the power
socket or the terminal box are clearly located outside of the hazardous area.
14 / 27
Ω
Attachment Commutator Motors (explosion-proof)
2
3
Ω