Short Circuit Study
To accurately perform an arc flash study, it is required to perform a short circuit analysis in tandem, as the study can help any data center, industrial or chemical plant operate more reliably. This allows facility managers to take advantage of the information at a reduced cost compared to doing the studies on their own.
One of the most fundamental and important calculations made on an electrical system is that which yields available short circuit current.
The maximum available short circuit current is a parameter every facility manager should know, as it provides a data point necessary to ensure equipment is being applied within its rating and the system can meet the expectations placed on it.
The short circuit study is based on a review of one-line drawings by a professional engineer.
Maximum available fault current is calculated at each significant point in the system. Each interrupting protective device is then analyzed to determine whether it is appropriately designed and sized to interrupt the circuit in the event of a bolted type of short circuit.
Short circuit information is required in order to analyze an electrical distribution system to determine if changes can be made to mitigate arc flash hazards.
A minor change in an adjustable breaker may make the difference in the result of an arc flash hazard category 4 or a 2.
The availability of the short circuit information is a standard output of an arc flash study calculation, however, there is a big difference between having the information available and doing a report.
In fact, future standards for conducting an arc flash study will most likely include a short circuit study in order to help standardize the expected results of an arc flash program.