Pyrotenax mineral-insulated (Pyro Mi) fire survival cable has been employed at St. Paul’s Cathedral in non fire-rated applications requiring a long-term, ‘fit-and-forget’ solution without the additional need of conduit or trunking for protection. It has been installed both embedded in the building fabric and surface mounted in non-concealed applications for sub-main power distribution to specialist lighting circuits and the new electric entrance doors.
St Pauls Cathedral has recently undergone a major cleaning and restoration project to improve the visitor experience ready for its 300th anniversary, and Speirs & Major Associates were given responsibility for relighting the Cathedral. The installation required new circuits and extensions to existing wiring and Pyro Mi cable was chosen for this application as it offers longevity and full mechanical protection without conduit or trunking. Light Perceptions, the systems integrators, coordinated the installation with electrical contractors Mid Essex Electrical and over 8km of this heavy duty cable was installed. Pyro Mi has excellent handling characteristics, making it easy to install, and has a non-organic construction which provides excellent mechanical protection and rodent resistance to provide a maintenance-free solution that will retain its integrity over decades.
Indeed, much of the existing lighting circuitry at St Pauls Cathedral was Mi cable, installed back in the 1950s and still in good condition after 50 years of service – a testament to the longevity of this cable type.
Whilst recognised as a true fire-survival cable, capable of retaining circuit integrity throughout and after intense fire, Pyro Mi is also an increasingly popular choice for non-fire rated applications. It has been installed in many historic buildings where longevity is an essential requirement and where limited space or aesthetic considerations preclude the use of protective conduit and trunking.