I work in a building where we recently (2 years) had a 110v Central Battery System that was specified to supply a 3 hour supply in the event of a mains failure! Is it correct for the installer to conduct Yearly checks and undertake a 1 hour discharge test. I think it should be 3 hrs? Is there an REG/ACOP/GI that states 3 hours?

Thanks
Rees

Full rated discharge, if it's a 3 hour system it should be tested to 3 hours. The lighting standards do still refer to certain building types only needing one hour (despite it being decades since 1 hour fittings were discontinued) however the same standard says that the annual test must be to the full rated duration (inevitably 3 hours).

Note that there is a difference between escape lighting, emergency, lighting, standby lighting etc so whilst 1 hour may meet escape requirements your installation may be intended for other purposes in addition where 3 hours is needed.

As AB has said three hours should be used however there are no REG/ACOP/GI 's that I am aware of but BS 5266 is considered the best practise by the courts so this is the guidance used. http://shop.bsigroup.com/ProductDetail/?pid=000000000030331554

Check out http://www.firesafe.org.uk/emergency-lighting/ may be of use.