Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...

I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...

Many questions sent in to the site are in connection with motor starting and in particular star-delta.  For all but the simplest application, there is...

In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...

Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or...

When thinking about watts (W) or kilowatt (kW = 1000 W) it can be useful too keep in mind the fundamental ideas behind the unit. Watt is not a pure electrical...

Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...