Electrical and related buildings technology
A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable drive units to control the...
The image (reproduced from IEC 60909) shows a typical fault in an ac system. From the illustration it can seen that there is an initial dc component ...
Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower...
Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...
Ever wondered what kind of power an aircraft uses when parked at the airport stand. Normally the aircraft generates it own power, but when parked with...
The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...
A frequent problem in fault calculations is the obtaining of equipment parameters. While it is always preferable to use the actual parameters of the equipment...
The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional...
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