We have recently installed an emergency lighting system with a central battery back-up. This provides battery back-up to a lighting distribution board serving a number of lighting circuits. If there is a mains electricity failure to the whole installation the inverter will provide the back-up supply, however if an MCB/RCBO trips on the inverter supplied DB there will be no back-up to that circuit. Is this satisfactory, if not how could this be rectified.

Many Thanks

This sound like Standby lighting and not Emergency escape lighting, the former is not required by the fire safety legislation. Emergency escape lighting is operated by battery supply and has to illuminate all escape routes for the safety of people leaving a location or attempting to terminate a potentially dangerous process beforehand. It is part of the fire safety provision of a building and a requirement of The Regulatory Reform (Fire Safety) Order 2005. Check out http://www.firesafe.org.uk/emergency-lighting/ for more information.