Central Power Supply Systems

Testing Requirements for Central Power Supplies

A central power supply system must be subjected to periodic testing under BS EN 50171. Whilst BS EN 50171 covers central power supply systems (for use with life safety circuits and emergency lighting), emergency lighting itself is also subject to BS EN 50172/BS 5266 testing. Many UK installations combine BS EN 50171 requirements with emergency lighting testing requirements from EN 50172/BS 5266. The actual intervals and procedures are also influenced by national codes of practice such as the UK fire safety law.

For more information on the UK fire safety law see:
https://www.fia.uk.com/static/uploaded/27153bfc-1f9d-4cfa-91e7b79015bfb49f.pdf

The mandatory and required period testing under BS EN 50171 includes:

• A Full Discharge Test: the CPSS is discharged under load to verify battery runtime available. This must be completed every 12 months (either manual or automatic) and should be conducted or two-thirds of the rated duration checked to ensure the battery retains the appropriate voltage.
• Functional Load and Switching Test: to simulate a mains power supply failure and verify load switching to battery power and emergency load support. This should be at least once per week for an automatic system. The test duration should be 10seconds to 5minutes per cycle, with a total requirement of less than 10minutes per week.
• Manual Test: to test that the system can be manually started and is available. Manual testing can replace automatic testing if a warning appears after 12 months without an automatic test but any fault should be noted and reported immediately.
• Battery Charge Monitoring: to ensure that the charger and battery are functional. The monitoring should be continuous with periodic checks (under 5 minutes). In automatic systems, continuous or frequent monitoring is mandatory to ensure system availability.

All faults and checks must be logged and recorded with test records available for inspection and ongoing compliance checks.

In summary, a CPSS should be subjected to weekly functional testing, regular battery charge and system health monitoring, an annual full discharge test (manual or automatic), fault notification and record keeping, inspection and verification by a competent person.

For more information on our Central Power Supply Systems please contact our Projects Team for project review and site survey.