Management of Extremely Low Frequency Electromagnetic Fields (ELF EMF); which is classified in the 1 to 3,000 Hz range. It is important to note that Australian power frequency of 50 Hz lies in this range.
The first step involves a compliance assessment of existing ELF EMF in a specified area, structure, electrical assets, building or facilities; to EMF exposure reference levels as per Australian standards (ENA, ARPANSA) and / or company policies.
This assessment is provided to determine compliance to the general public exposure levels and occupational exposure levels.
This assessment excludes exposure of both operator and patient to medical equipment, radio frequency, mobile phones and wi-fi.
Assessment is carried out with:
Evaluation of an existing earthing system (i.e. in a substation or transmission line) against the allowable safety criteria in ENA EG1 and / or company policies; to determine the maximum earth potential rise (EPR) in an earthing system during a fault and indicate if there are dangerous potentials (such as touch, step and transferred voltages) across the installation.
This work requires on-site testing which can include:
Using the fall-of-potential method, the EPR across the installation can be determined and subsequently the earthing system resistance.
Touch / step and transferred voltages (i.e. in metallic structures such as gas / water mains and telecommunication services) can be measured to determine compliance or the need of remediation works where applicable.