Periodic inspections of earthing and short-circuiting devices
New test method for portable earthing devices
Copper corrosion and breakage of conductor strands can reduce the cable cross-sections of portable earthing devices. This can have severe consequences (fatal electric shock or burns caused by arc faults) e.g. in case of accidental re-connection of an electric system.
As is the case with electrical equipment, it is mandatory to test earthing and short-circuiting devices. Until now only a visual inspection of EaS devices at regular intervals made economic sense.
A new method is now available, which provides more detailed information on the overall condition of an earthing device based on a static and dynamic measurement of the ohmic resistance.
The device is tested in three steps:
- Visual inspection for signs of damage
- Static measurement – Measurement of the total resistance on the stationary EaS device
- Dynamic measurement – Measurement of the relative change in resistance on the portable EaS device
The software provides clear, reliable information on the condition of the earthing device. The results of the technical test are shown in the form of a traffic-light display:
|Limit values are not kept.|
Repair or scrap the earthing device!
|Limit values are just kept.|
Schedule for maintenance.
|Limit values are fully kept.|
No further steps are necessary.
More than one and a half years of practical experience revealed that hidden damage, which cannot be detected by a visual inspection, can be found on numerous earthing and short-circuiting devices. This clearly shows that regular periodic inspections using a more exact test method are necessary.