The Uninterruptible Power Supply Unit NTU/S 12.2000.1 is a modular installation device in ProM-Design, for snap-on mounting on a 35 mm mounting rail in a universal, wall-mounted or ceiling panel distribution board as well as in distributed surface mounted housings. The power supply delivers sufficient power for all types of demanding applications with a buffered output voltage of 12 V DC (SELV) and a maximum output current of 2 A. Operating malfunctions of the power supply are signalled via a changeover contact and can be sent for evaluation purposes. Up to two 12 V DC sealed lead-acid batteries (gel cell) can be connected in parallel with the power supply, in conjunction with the KS/K 4.1 and KS/K 2.1 cable sets, or the AM/S 12.1 battery module.