Power Systems International Aids Cambridgeshire County Council In Emergency Evacuation Lift Initiative

Cambridgeshire County Council’s Client Property Engineering Manager, Roy Drayton has collaborated with the power engineering experts from Power Systems International to develop a purpose built low energy consumption standby power system for dedicated use in emergency evacuation lifts.

The Emergency Power System (EPS) can be used on any lift, whether traction or hydraulic, in a public building consisting of three floors, the average size of most municipal premises in the UK. With its main application in schools, hospitals and libraries the team was keen to build a cost effective and eco-friendly unit that uses little energy in quiescent mode. The new system consumes 50 watts of electricity in its quiescent mode; i.e. as much as a household bulb. In comparison to a conventional UPS of 20kVA that would have losses of 2kW. For public buildings and schools this is quite a significant energy saving and thus has excellent ‘green’ credentials.

The unit is a compact dimensioned standby power system built in a steel enclosure comprising a high performance rectifier battery charger, maintenance free battery and an inverter with automatic bypass feature.

In an emergency situation, an authorised person switches the EPS on by using a remote control key, like the ignition switch in a car. This powers the lift hoisting system from its internal inverter and batteries independent of the mains power. The “on emergency power” button illuminates to signal power is being provided to the lift traction system from the EPS system. It is then possible for the authorised person to operate the lift for as for as many as 10 upward and 10 downward journeys within the one hour period as stipulated in the EN-British Standard specification.

A summary alarm signal is also provided for connecting to a building management system.

Cambridge County Council has successfully installed the EPS power systems in a number of schools and libraries in the area including the Nene School, the Netherhall School and Huntingdon Library with full co-operation from lift manufacturers Oakland, Schindler and Kone.