We have a customer who owns a series of 24 and 30 unit apartment
buildings. Presently on each floor as per local requirements there are
several self contained emergency lighting units. Some of these are
equipped with a small 6V battery and just two low voltage lamps that
aim in different directions down the hallway, while other larger units
having larger batteries sometimes might have as many as six 12volt
lamps wired remotely. These all are equipped with sealed lead acid
rechargeable batteries which need to be replaced every few years. Two
of his buildings are exceptions though and don’t have this type of
lighting. In these buildings, the hallway lighting circuit is wired
through an inverter system. This system, which was built by a company
in Massachusetts many years ago is installed in the boiler/electrical
room, and consists of two 12VDC to 120VAC 450W solid state inverters
operating in parallel and two group 24 size wet cell automotive
batteries. There is a built in charger and a huge contactor which
drops out upon loss of AC and applies 12VDC to the inverters. Loss of
AC will cause the load to toggle over to the inverter outputs and the
hallway lighting circuit remains powered. Maintenance on these two
buildings is minimal and his ultimate cost savings projection becomes
significant when multiplying installing this type of system into the
100’s of buildings which he presently owns. He has asked me to look
into finding this type of equipment for him to retrofit his other
buildings. The typical load is about 400W CFL and will probably never
exceed 550W. I don’t know how picky these particular 13W CFL units are
to anything other than sine wave AC. I know sine wave or even modified
sine wave will probably increase cost somewhat. Does anyone have any
ideas for inverter systems equipment they might be able to share with
me? Thanks, Lenny.