| If
the building is to be evacuated following primary power
failure, a secondary power supply shall be provided. This
shall be capable of operating the system in the emergency
mode for a period equal to twice the evacuation time determined
by the appropriate authority for the building. In any
event, the secondary power supply shall be capable of
powering the system for a minimum of 30 minutes. |
| |
| If
the building is not to be evacuated following failure
of the principal power supply, the secondary power supply
shall be capable of operating the system for at least
24 hours, or 6 hours if an emergency generator is available,
and then powering the system in emergency mode for a minimum
of 30 minutes. If a building remains unoccupied for several
days, provision should be made to ensure that the voice
alarm system is capable of operation in emergency mode
for 30 minutes when the building is re-occupied. |
| |
| Non-emergency
functions within the system, such as background music,
shall not operate from the secondary power supply if this
will reduce the capacity for emergency operation. Praesideo
has the facility from software version 1.1 for the BGM
to be deactivated. |
| |
| If
batteries are used as a secondary power supply they shall
be of the secondary type, complete with automatic charging
facilities. Where lead-acid batteries are used they shall
be of the valve-regulated type unless otherwise specified,
and the charging system shall incorporate charging current
compensation for changes in the ambient temperature, where
this is necessary to achieve the specified battery life. |
| |
| Batteries
shall be used in accordance with the manufacturers recommendations
in order to achieve their specified life, which shall
not be less than 4 years. The end of life shall be taken
as the time when the deteriation to less than 80% of the
rated ampere-hour capacity (at the one-hour rate) has
occurred. |
| |
| Automatic
charging shall ensure that the batteries are fully charged
to 80% of their maximum rated capacity from the fully
discharged state in a period of not more than 24 hours. |
| |
| Adequate
ventilation and protection against corrosion and dangers
resulting from gases emitted by the batteries shall be
provided. |
| |
| Please
note that the above requirements are the responsibility
of the installer |
