Economic Considerations for Reserve Telephone Power

Considering alternate sources of power during commercial AC power failure, telephone engineers are faced with three common options: 1) A battery reserve normally ranging from three to eight hours of DC power. 2) A stand-by engine (usually a diesel engine or turbine) to provide AC power as substitute for commercial AC. 3) A combination of the first two options. Once reliability and office integrity criteria are satisfied, it is possible to vary the extent of options 1 and 2 to achieve the most cost effective combination without jeopardizing telephone service.