Northern Ireland Electricity has become the first United Kingdom utility to order Eaton’s environmentally friendly Xiria ring main units as part of its framework contract for secondary power distribution. The Eaton Xiria RMU was assessed during 2005 and holds the ENA (Energy Networks Association) Notice of Conformity Certificate Number 1040 for use in the United Kingdom up to 11kV.
Xiria is a compact ring main unit for applications up to 24kV. It uses vacuum circuit-breakers for circuit interruption and solid/air insulation, rather than SF6 gas insulation, therefore there are no environmentally unfriendly greenhouse gases involved. Since its launch in 2001, more than 2500 Xiria units have gone into service worldwide with utilities, industry, commerce and public services. In the United Kingdom, Xiria units are already used by several leading industrial organisations and a major London Hospital.
Xiria offers high levels of operational safety and reliability. It can be used on automated distribution networks, making it adaptable to changing network requirements. All the live primary parts and mechanisms are fully enclosed for protection against dust and other external influences. The switching mechanism has a minimum number of components and is lubricant-free. All this makes for freedom from maintenance and reliable operation.
Eaton does not utilise SF6 in any of its switchgear products because it is one of the greenhouse gases listed under the Kyoto Protocol, with the highest global warming potential (GWP 23,000).
The benefits of Xiria ring main units are particularly significant inside buildings. There is no oil to leak, no gases to escape and no risk from dangerous or toxic products of decomposition produced by arcing. The equipment itself is compact so it takes up a minimum of valuable floor space.
For added safety when working on cables, Xiria has inspection windows that provide direct visual inspection of the isolation distance between earth and the busbar system.