Web Rail Global Glossary
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High VoltageThe rail industry generally considers high voltage as above 1kV ac, and at least 1.5kV dc. Low voltage is considered to be between 50 and 1kV ac and between 120 and 1.5kV dc. Extra-low voltage is considered less than 50V ac or less than 120V dc. These are the standards of the International Electrotechnical Commission and its various associated bodies (IEEE, VDE, IET, etc.). | |
High-availability clustersHigh-availability clusters (also known as HA clusters or fail over clusters) are groups of computers that support server applications that can be reliably utilised with a minimum of down-time. They operate by harnessing redundant computers in groups or clusters that provide continued service when system components fail.
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Home SignalA home signal is an absolute signal that advises a driver if it is safe to enter the station block. The signal may display:
The term home signal applies to more than a station. Home signals protect junctions, points, level crossings, movable bridges, platforms, or block sections. See also its opposite, the starter signal. | |
Human-Machine InterfaceA discipline which studies the effectiveness of communication between humans and machines. | |
HVACAn acronym for heating, ventilation and air conditioning |
HyperlinkBlue writing (sometimes with an underline) in the Web Rail site. You will encounter many of these in our courses and if you click on them they will take you to special places such as documents, web sites or a glossary of terms. | |