The New British Post Office Standard Power Plant 235/236

A new British Post Office standard power plant has been designed to operate from a single-phase a.c. mains or standby generator input, and to provide secure d.c. power to 50 V telecommunications equipment. The plant features standby rectifier capacity, battery standby with a choice of duration, and a regulated output during battery discharge without the need for end-cell switching. A range of standard equipments with ratings up to 80 A, using common control circuitry, has been developed. Features of the plant include simple installation and maintenance, freedom from output voltage transients, and reliability of the d.c. supply.