Topics in Escalator Electrical Design

This paper attempts to discuss various topics in escalator electrical design. It concentrates on the use of the various electrical standards and how they relate to each other and to the escalator standards specifically. It introduces the concept of the so-called electrical standards pyramid, and how it relates the escalator system components and to the electrical systems in general. Following a general introduction to the concept of a safety device in the escalator control system, the safety devices within the escalator system as required by EN 115 are discussed. The implementation of safety critical devices within the escalator controller is discussed, in the form of the so-called safety relays. Within modern control systems, there is a need to monitor the status of safety devices in order to feed this information into a remote monitoring system, or just for simple maintenance information systems. Different methods for safety device monitoring are discussed, with the advantages and disadvantages of each.