Electrical Continuity

Ningbo Bonet Metal Products Co.,Ltd | Updated: Apr 20, 2017

Electrical Continuity

Cable tray systems shall have adequate electrical continuity to ensure equipotential bonding and connection(s) to earth if required according to the application of the cable tray system. Electrical continuity provids safety to people and property, and plays an essential role in the EMC performance. Thus cable trays must connect with each other by using couplers.

The standard IEC 61537 states that the cable tray systems impedances shall not exceed 50 mΩ across the joint and 5 mΩ per meter without the joint. We guarantee the resistance of our products does not exced 5mΩ/m for wire mesh cable tray straight sections and not exceed 1mΩ for wire mesh cable tray couplers. This is better than the standard required.

Cable Tray Earthing (Grounding)

To make the whole cable tray system safe to people and equipments, as well as achieve excellent EMC levels, cable trays should be integrated into the earthing network. For power cables, metal cable trays must be connected to the earthing(grounding) network every 15 meters. For data cables, it is suggested every distance connected to the earthing network not surpass 20 meters.

Our wire mesh cable tray systems could be connected to the earthing network by using copper earthing bolt as below.


Shortcircuit Resistant

When there are damages occured on insulating materials of cables, cable trays are then be subjected to a big mechanical stress (mutual electromagnetic repulsion between the power cables) caused by short circuits. Our wire mesh cable trays can withstand a repulsive force of about 45,000N, which is correspond to a short circuit current of 130kA occured within approx 0.2 second.

The mesh structure of wire cable trays is able to absorb the physical stress generated by a significant short-circuit current and shows no permanent deformation. Nevertheless we strongly recommend to integrate the cable tray systems with earthing systems.

Please note that powder coated cable trays do not conduct electric currents. Thus powder coated cable trays are only suggested to use for data cabling systems only.