Talk:Fault current

Questions/comments about Fault Current page
Please place all comments/ questions here Thank you

Information and examples of fault current calculations would be great.

Hey, we've only just started this page. Give it a chance for some contributions!!Light current 21:33, 13 August 2005 (UTC)
 * Not to seem pushy, but it's been 6 weeks since this page was created, and there hasn't been any added info at all. Can a topic such as this one really be expanded into an encyclopedic length article??  As it stands it is a clear cut canidate for Wiktionary, simply because it is nothing more than a dicdef.  -- Malo 04:57, 1 October 2005 (UTC)

Can anyone tell me the prospective short circuit current between phases of a three phase supply, is it; Twice the phase to neutral value, three times the phase to earth value, 500V or 230V ? —Preceding unsigned comment added by 88.109.123.4 (talk) 15:40, 20 October 2008 (UTC)

Definition
A term generally used to indicate an abnormal and undesired flow of current in an electric circuit due to a fault (usually a short circuit or abnormally low impedance path). The term is most commonly used in the electricity supply industry. Depending on the source impedance, fault currents can reach thousands of amps.

Fault Current Detection
When a fault current is detected, this will usually operate (or trip) a circuit breaker at the local substation by means of a magnetic trip mechanism incorporated in the circuit breaker.

Fault location schemes
There are a number of systems in present use to detect the location of faults such as: These location systems enable the electricity supply engineers to quickly travel to and repair a fault.

Fault current limiting
A number of techniquaes exist for limiting of fault current. One early method was to insert a large reactor (inductance) in series with the load. THis would limit the current due to its reactance. REcent advances have seen experimantal limiters based on superconducting materials where the material reverts to a high resistance when above its critical temperature

Beneficial effects of faults
The occurence of faults is not a completely negative event. The occurence of a fault can allow sophisticated test equipment installed at a substation to indicate the impedance of the line and thus determine the prospective short cicruit current (PSC)(or fault current limit)