Railway tanker earthing control system
Newson Gale Earth-Rite PLUS
The Earth-Rite Plus type earthing control system is designed to eliminate the risk of ignition of the flammable atmosphere as a result of the jump of an electrostatic spark. The solution of this series is most often used for rail tankers and various types of containers and tanks.
Principle of operation of the system
The principle of operation of the Earth-Rite Plus system is based on continuous control of the connection of the tanker (or other object requiring earthing) with the earthing point. This connection is made by attaching a cable with a clamp to the road tanker structure. The system is calibrated to activate the devices responsible for the medium transfer (pumps, valves, etc.) only when the resistance of the earth connection is less than 10 Ω. When this resistance increases above the limit, e.g. due to wire damage or breakage of the clamp, the process will stop.
The system is equipped with a light-emitting diode signalling device that informs the operator about the correct earthing of the road tanker. A red light means that earthing has not been done properly and therefore the system will not allow the start of the unloading/loading process. In addition, if an incorrect earthing is detected during transshipment, the process will be stopped.
System components
- earthing monitoring unit,
- junction box for hanging up the clamp,
- earthing clamp with a wire.
Case study – monitoring of the earthing of road and railroad tankers
Within the construction of a new power unit, we have furnished nine stations for road and railroad tankers unloading with earthing systems including earthing system status control. This resulted from the risk of electrostatic discharge during the unloading process which is going to be made at the power plant, whereas unloading may be a potential source of ignition in explosive atmosphere.
Important
Loading or unloading of railway wagons with liquids or powdered solids can cause strong electrostatic charges, resulting in a serious risk of creating a potentially explosive atmosphere. Although a railway wagon is in contact with earthed rails, many tanks are equipped with non-conductive bearings and abrasive components, located between the railway wagon itself and the wheel sets. This can cause a dangerous situation, as an unearthed railway wagon accumulates strong electrostatic charges.
