Periodic Electrical Installation Inspection – How Often?
How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...
Dielectric loss in cables
Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss. The varying electric field causes...
Paternoster Lifts
These lifts were first built in 1884 by J. E. Hall and called a paternoster ("Our Father", the first two words of the Lord's Prayer in Latin) due to its...
Questions - Reputation and Privilege
Our question and answer system while letting you do exactly what it says, is much more. It is a dynamic user driven system, where our users not only ask...
Lightning Risk Assessment (IEC 62305)
IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...
Gas Insulated or Air Insulated Switchgear
Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...
Voltage Levels – Confused?
I was having a conversation the other day about voltage levels. While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...
Batteries
A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these...
Earth Electrode Resistance
Earthing of electrical systems is essential for the correct functioning and the protecting of life and equipment in the event of faults. The earth electrode...
IEC Document Designation
Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...