Do I really need to test emergency lights for three hours

[Guest MikeP]

Hi,

Can you please help, I am having problems understanding the battery requirements of my emergency lights. The company I use "Fire Safety Services" insist on testing my lights to 3 hours (actually 2 + 1 but that doesn't make sense to me). I am saying that I believe that as per BS5266-1 2016 (I do not have a copy) I can (I run an office and medium size warehouse facility) with the correct procedures i.e. immediate evacuation and a no return policy, test to 1 hour duration. Can you please confirm and give me an example from BS 5266-1 2016 where this is stated.

Thanks

[AnthonyB]

The 1 hour/3 hour requirements are a bit of a throwback to the early days of emergency lighting when both types of fitting were available (both self contained and central battery) and technology was such that central battery systems were more common as they were the easiest way of getting 3 hours duration, self contained fittings technology was such that 1 hour was what you could easily manufacture using the technology. Therefore most applications in single stage evacuation premises would be 1 hour and the standards only asked for this as it was considered sufficient for the occupancy and risk.

 

Technological advances soon meant that fittings could be produced with 3 hours duration that were the same size and almost same price as the old 1 hour fittings and to avoid duplication in manufacture 1 hour fittings were dropped by the majority of manufacturers several decades ago (you can still get them if you search hard). The standards however have not been updated to reflect the change in technologies available.

 

As such virtually all fittings installed are of 3 hours duration, regardless of the minimum duration required for different Purpose Groups.

 

BS 5266-1: 2016 has the following PPM regime:

 

Functional operation should be checked at least every month.

Testing for full rated duration should be performed on each luminaire at least annually.

As the full rated duration of emergency lighting fittings is now almost universally 3 hours, as it is so long since 1 hour units were widely available and used, then it is correct to expect full duration tests.

 

The 6 monthly partial duration test was removed in part due to the deleterious effect on NiCad battery cell life as most systems use this technology compared to back in the late 20th century when there were a lot of lead acid battery central systems and other battery technologies and full discharge cycling is recommended for this battery type. (With Lithium Ion batteries as used in phones the opposite is actually the case)

 

The point over loss of service during recharge times is correct, hence on weekday operation premises it's best to schedule tests for Fridays. In premises with wider hours of operation then testing should be either at times of minimal risk (low occupancy, summer, etc) or alternate testing of units should be carried out.

 

Testing a 3 hour system for 1 hour falls outside of BS recommendations and will have a deleterious effect on fittings (eventually the safety factor will be lost as they will eventually last for less and less than 3 hours down to 1 hour) and would not normally be accepted although it can be considered on a case by case basis