Specialist Services // Protection Studies

Hirst Electrical undertake protection studies to provide protection settings and CT specifications based on system evaluations including motor starting, maximum demand, fault levels, transformer inrush currents and grading requirements. Existing protection systems can be optimised or new systems designed, specified and implemented using discreet relays or programmable multifunction protection relays. Protection schemes undertaken vary from motor protection to unit protection and high impedance busbar protection with Class X current transformers.

Once modelled, future updates are easily achieved when a client system changes.

Short Circuit Studies

A short circuit analysis models the currents that flow in a power system under fault conditions and determines the prospective fault currents in the electrical power system. These fault currents must be calculated in order to adequately specify electrical apparatus. The study results are also used to selectively co-ordinate time current characteristics of electrical protective devices.

The systematic short circuit study methodology begins by creating a system one-line diagram, thus defining all electrical characteristics of the power system. Hirst Electrical utilise the AMTECH Electrical Power Software to compile the short circuit studies. The software calculates the currents for a fault at every bus or node bus within the system.