About – Paxton supply a range of 12V dc power supplies for use with our systems. All are designed to connect to a standard UK mains supply via a switched fused spur connection. 998-241 is a 1A 12V dc power supply in a plastic enclosure. This is a low cost alternative to the boxed backup power supplies. 857-250 is a 2A boxed backup power supply. This means that when installed with the appropriate battery (listed), the power supply will continue to provide 12V dc for an extended period in the event of a power failure. The exact duration of the backup period will be dependent on the power consumption of the access control system and the capacity of the battery. 857-090 is an unboxed variant of the above power supply. Installation – Installation for each power supply differs. Instructions are supplied with each unit.