Lead us, Warleader
Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."'
Reading is something I do...
DC Motor Operation
Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...
Hazardous Areas – IEC and NEC/CEC Comparison
Depending where in the world you work, you are likely following one of two standards
International Electrotechnical Commission (IEC)
National...
Understanding Motor Duty Rating
One of the comments on my Motor Starting Series was asking for something on duty cycles. Here it is.
As a purchaser of a motor, you have responsibility...
Fault Calculation - Per Unit System
Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base. By removing...
Low Voltage Fault Tables
The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.
Differential protection, the good old days
This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...
Medium Voltage Switchgear Room Design Guide
Many medium voltage (MV) indoor switchgear rooms exist worldwide. The complexity of these rooms varies considerably depending on location, function and...
Smarter Electrical Distribution
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...
Equipment Verification (to IEC Standards)
One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...