There are mistakes and habits related to the back-up power supplies (batteries) in our country in general and some important issues are mentioned in the following paragraphs.
In the fire detection and alarm systems, redundant power supplies are used in line with the criteria set forth in TS EN 54-14 (Fire detection and fire alarm systems - Part 14: Planning, design, installation, commissioning, usage and maintenance guidelines) and the battery capacity calculations. The back-up power supplies must be approved in accordance with EN 54-4 (Fire detection and fire alarm systems - Part 4: Power supply equipment) as specified in TS EN 54-14 standard.
The standard UPS system is widely and erroneously used, especially for back-up power supplies used in the field. TS EN 54-4 approved batteries should be used for the detection and warning devices that are a part of the fire detection and alarm system and require a separate power supply.
One of the general mistakes is that the waiting time in the back-up power supply (battery) capacity calculations is calculated over 24 hours. However, in TS EN 54-14, in accordance with specific criteria, battery waiting times are determined as 72 hours, 30 hours and 4 hours.
According to the article A.6.7.3 of TS EN 54-14;
As a precaution against failures that may occur in the main supply source, the backup supply system shall be able to keep the system in operation for at least 72 hours and shall be able to feed the alarm load for at least 30 minutes after this period.
The minimum back-up capacity can be reduced from 72 hours to 30 hours in the cases where a failure warning is immediately given from the local or remote supervision of the system and where the repair contract gives a maximum repair time of less than 24 hours. This period can be reduced to 4 hours if the spare parts, repair personnel and the backup generator are always available on site.
The backup times given above are sufficient for the normal applications. In certain applications, longer periods may be necessary.
Likewise, the backup power supplies must be EN 54-4 approved for the emergency announcement systems as specified in TS EN 54-16 (Fire detection and fire alarm systems - Part 16: Audible alarm control and indicator equipment) and TS EN 54-32 (Fire detection and fire alarm systems - Part 32: Planning, design, installation, commissioning, use and maintenance of audible alarm systems).
According to TS EN 54-32 standard, the waiting period is calculated as 24 hours in the backup power supply (battery) capacity calculations and 30 minutes in case of alarm.
In the article 4.3 of TS EN 54-16 standard, the following descriptions are available for power supplies;
The power supply equipment may be inside or outside the Control and indication assembly and shall comply with the requirements of EN 54-4.
Note: The power supply can be used in common with the fire detection and alarm system.
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