short circuit studies
A short circuit study calculates the maximum current electrical equipment will experience in a short circuit event. It helps to select and confirm the required withstand ratings of the electrical equipment before it is installed. It is generally used in commercial facilities, industrial plants and all locations where new or existing electrical equipment is installed or retrofitted.
The short circuit study is a critical step in the construction process. It confirms all the equipment selected by the designer will withstand the largest stresses it may be subjected to. It also verifies that the electrical equipment is adequate for the location where it will be installed.
A short circuit study must compute and analyze a three-phase balance short and all unbalance shorts variations. The three-phase bolted short generally yields the largest short circuit current. A three-phase short circuit occurs when all three phases ABC of the electrical system are simultaneous bolted together. The short circuit created is fed by all three phases ABC.
Unbalanced phase shorts circuit currents must be also calculated by the short circuit study. Unbalanced shorts circuits typically generate smaller currents than three phase faults. However, there are a few cases and locations where the unbalanced faults are larger than three phase faults. Unbalance faults can be as 115% larger than three phase faults. One locations where the unbalanced fault is larger than three phase faults is at the secondary of wye grounded transformer.
The short circuit study must incorporate all parts of the electrical distribution system. Some of the critical equipment that must be included in the short circuit study are:the Utility Company connection point data, Motors, Generators, Transformers, Cables, one-line diagrams and operating scenarios.
The short circuit study is a critical step in the construction process. It confirms all the equipment selected by the designer will withstand the largest stresses it may be subjected to. It also verifies that the electrical equipment is adequate for the location where it will be installed.
A short circuit study must compute and analyze a three-phase balance short and all unbalance shorts variations. The three-phase bolted short generally yields the largest short circuit current. A three-phase short circuit occurs when all three phases ABC of the electrical system are simultaneous bolted together. The short circuit created is fed by all three phases ABC.
Unbalanced phase shorts circuit currents must be also calculated by the short circuit study. Unbalanced shorts circuits typically generate smaller currents than three phase faults. However, there are a few cases and locations where the unbalanced faults are larger than three phase faults. Unbalance faults can be as 115% larger than three phase faults. One locations where the unbalanced fault is larger than three phase faults is at the secondary of wye grounded transformer.
The short circuit study must incorporate all parts of the electrical distribution system. Some of the critical equipment that must be included in the short circuit study are:the Utility Company connection point data, Motors, Generators, Transformers, Cables, one-line diagrams and operating scenarios.