BS EN 60839 / IEC 60839 is the European and Global standard for access control systems

The power supply requirements for such systems is covered under BS EN 60839-6.9. This states that the access control unit shall be provided with a standby power source capable of operating the unit, and its accessories, under specified full load conditions for the period of time indicated.

Power supply requirements

1. The power supply shall be capable of supporting the electronic access control system in all conditions including recharging of the standby power source within the period specified for that grade of system.
2. The power supply may be placed in one or more components of the electronic access control system or, in a separate housing.
3.  Extended primary power source failure (system shutdown occurred) and restoration of power, rechargeable batteries shall be recharged to 80 % of rated capacity within 24 hours and 100 % of rated capacity within 72 hours
4. If a standby power source is provided provisions shall be made to monitor for the following conditions: low voltage level and no battery present (a single common annunciation for both conditions is acceptable

Dycon's D1460-range 9A power supplies are compliant with this standard.