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Class II

Class II Safe By Design

Traditionally, signalling power supplies have consisted of a Class I, 650VAC feeder cable. Class I refers to a system that has an earth return so that any fault in a particular location will divert stray current to an earth point, thus protecting someone from an electric shock. This is a costly system requiring robust earthing arrangements at all locations and a three-core power cable with earth return conductor. 

Because of the way that cable design takes into account earth return currents, it is possible for the size of the size of the earth return conductor to be larger than the individual phase conductors, this can mean that the cable is sized to the larger earth conductor, thereby using a third more copper than necessary to carry the supply. 

Safety is a further concern, given the many cable thefts in recent years. With theft and vandalism, there is a risk that the earth return system could become compromised leading to death or serious injury. 

Enter Class II power supplies. Class  II, or double-insulated, electrical equipment is designed in such a way that it does not require a safety connection to electrical earth. The basic requirement is that no single fault can result in dangerous voltage becoming accessible so that it might cause an electric shock, and is achieved without relying on an earthed metal casing. This is usually met by having at least two layers of insulating material between live parts and the user, or by using reinforced insulation. Not only is there a safety benefit with Class II, but the availability is far greater as the supply is not tripped due to a cable fault.

iLECSYS Rail - Supporting the requirement for a safer, performance enhanced Infrastructure

iLECSYS Rail have worked closely with Network Rail to support the introduction of Class II signalling power supplies onto the UK rail infrastructure. In support of Network Rail standards NR/L2/SIGELP/27410 Issue 2 and NR/L2/SIGELP/24709 Issue 2, we have successfully designed and manufactured many Class II products to support Network Rail in their pursuit of working towards a safer rail network. All Class II switchgear arrangements conform to BS 7671 (requirements for electrical installation) standards. 

Our range of switchgear has gained full product acceptance from Network Rail for use on their infrastructure. This range covers all versions from FSP01 to FSP04 versions. Switchgear assemblies have been designed in such a way that they are perfect for use within both new or retrofit configurations. Suitable for Copper (Cu) or Aluminium (Al) cables from 10-120mm2, our range of switchgear will allow for the direct connection of 2 core cable and 4 core cable via approved connection boxes. This supports Network Rail's Copper Elimination Challenge and allows for flexible solutions for installation and designs.  

Type Distribution Topology Power Supply FSP Supply Architecture
FSP01 Single end fed
(or sub-fed from main distribution system)
Single end fed
FSP02 Dual end fed Manual reconfigurable dual end fed radial with an open point
FSP03 Dual end fed Automatic reconfigurable dual end fed radial with an open point 
FSP04 (legacy) Single end fed
(or sub-fed from main distribution system)
Suitable as a direct replacement for existing isolation or fusing arrangements within legacy installations. 

iLECSYS Rail have designed a range of Earth Connection Boxes (ECBs) to support instances where there is a requirement to maintain the existing Class I topology. The existing earthing cable can be safely connected and sub-distributed without compromising the Class II user interface. This allows for a mix and match architecture to support design requirements and the interface with the existing infrastructure. 

 

FSP01/02

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FSP03

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FSP04 - Micro FSP

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Annexe FSP

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