06 August 2025 | Cranage EMC & Safety Ltd

Emergency Lighting Trouble Shooting

Having your product safety tested doesn’t mean that it is reliable, efficient and will give may years of trouble free use. It just means that it will be safe from hazards such as fire or electric shock when used. In this article we talk about a recent emergency lighting luminaire evaluation whereby the customer was experiencing issues with the product in the field.

Emergency lighting luminaires are designed to operate in a power outage situation for a set period. A customer contacted Cranage EMC and Safety after discovering that their luminaire did not operate during a power outage.

There are a lot of potential causes for this such as internal wiring issues, component assembly failures, or fuses operating. A visual review of the components and the data sheets implied all was in accordance with the standard, so more in depth testing and lateral thinking was needed.

Our engineer conducted a thermal test to establish the internal temperatures of the sealed luminaire, and this is where it became interesting. The internal temperatures saturated at 45c, which is not that excessive and the LED driver is rated at tA=50c, so that was well within the requirements of the standard. All other components were within their respective thermal limits, so no issues were seen in relation to the thermal testing of the product.

However there was a battery module that did not have a maximum ambient temperature declaration. This module has a metal ion battery and such batteries are susceptible to becoming unreliable at higher ambient temperatures.

After a vigorous investigation of the battery module it was concluded that these metal ion batteries have an optimal charge ambient temperature typically up to 35c. Any temperatures exceeding this then the battery can become stressed and loose its efficiency and fail, so after being subjected to a consistent elevated temperature the batteries in the emergency luminaire did not hold their charge and would operate for 30 minutes- if at all.

This shows the importance of the correct selection of components and where it will be applied. It is up to the design engineers to fully evaluate the product. Pre-approved sub components are a very good way of ensuring compliance, however they still have to be suitable for the applied application.

The product evaluated was safe, however unreliable after a year or so when installed, which is not what you need when it is relied upon in an emergency situation.

Get in touch with our team of expert engineers to discuss your lighting testing.

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