May 4, 2007 - Siemens Automation and Drives (A&D) is supplementing its "Sitop modular" series of power supply units with a 20-ampere basic unit for connection to the 3-phase 400/500 volt AC power supply. Only 70 millimeters wide, the new DIN-rail-mounted supply unit takes up less than half the space of its predecessor when installed. The 24 volt power supply unit, one of the narrowest and most compact in its performance class, is characterized by its high efficiency of 93 per cent, which results in very low heat losses.Like the other basic Sitop units of the modular series, the new 20 A version has a robust metal housing.
It comes with extensive functions for a wide variety of requirements such as short-time power boosting with up to three times the rated current or adjustable short-circuit behavior where it is possible to choose between latching OFF and constant current with automatic restart of the output voltage. As a new function, the DIN-rail-mounted unit can supply 50 per cent extra power for five seconds. This makes it possible to switch in loads with a high power-on current such as DC/DC converters and motors without any difficulties. The new DIN-rail-mounted power unit can also be combined flexibly with the extensive range of Sitop add-on modules.
Complete all-round protection can be provided: for example, protection against mains failure or selective protection against short-circuit or overload in the 24 volt output circuit.
