The function of an earth system for an electrical installation is threefold:

1. To maintain the potential of any part of the installation at a definite value (close to zero as possible) with respect to the earth.
2. To allow sufficient current flow in the event of an earth fault so that the protective equipment will operate and isolate the faulty circuit, preventing protracted heavy currents flowing which may result in possible fire hazard.
3. To ensure that in the event of an earth fault, equipment normally dead and un-energised i.e. electrical cabinets, cable racks, metal conduits, structural steel, etc. do not attain a dangerous potential above or below earth, creating an electrical shock hazard.

The Purpose of earthing is to increase safety. The objectives of good earthing practice are therefore to achieve at minimum cost, safe voltages, with the neutral close to zero potential, and to assist in detecting and disconnecting faults.

The aim of conducting a soil survey is to facilitate earth mat design. The target resistance is a calculated figure based on the surface resistivity, the fault current of the system, and the trip time of the protection equipment.

The resistance of an earth mat should be tested on a regular basis as part of the planned maintenance system. The results will inform the status of the earth mat and whether or not there are changes in the soil condition around the earth mat or if the mat has been damaged due to corrosion, etc.

Reasonable consulting fees to survey and report on the status of existing earthing, lightning protection, and static protection systems.

We advise on Policies and Procedures for testing and inspecting earthing and lightning protection systems, as guidelines towards implementing a Planned Maintenance Program.

We offer a comprehensive range of imported and local transient voltage surge suppression. Also advice on systems coverage which offers the best protection for all equipment from lightning induced, and other surges.

Training in:

• Practical Earthing to design phase
• Structural lightning protection design & implementation
• Static - understanding the principles, problems, and solutions
• Surge suppression - the devices and applications thereof
• Comprehensive course notes and Certificate of Attendance

Hosted and Maintained by Mark Levin Tel: (011) 454-1322