Maintaining Ex Lighting: Modular vs Sealed for Life – Part 2


30 April 2019

Part 1 – Modular vs. Sealed for Life – What’s the Difference?

In this four-part series, we compare ‘modular’ and ‘sealed for life’ LED Ex luminaires, and how the design and certification of these different approaches impacts how easily maintenance can be carried out.

In this second part, we look at how the design affects downtime during a common maintenance procedure. Let’s consider this in the context of a real scenario;

Application: Offshore, Oil Rig

Scenario: A luminaire installed on the rig has failed and is no longer providing light output. The suspected cause is a failure of the luminaire’s PSU/driver.

A PSU failure will result in either a partial or total loss of light from the luminaire. A loss of light may mean increased risk to workers on the rig, or operations may even have to stop which could have huge cost implications. Speed of resolution is therefore critical.

Sealed for Life Luminaire

Once a PSU has failed, if the luminaire is sealed there is nothing the rig’s engineers can do to rectify the problem; doing so would invalidate the certification. The luminaire must therefore be returned to the manufacturer. This takes time and is also environmentally irresponsible (which we’ll discuss later). The luminaire must be removed, the relevant paperwork must be raised, and arrangements must be made to get the luminaire, firstly, back to shore, and then back to the manufacturer.

At best, the manufacturer will be proactive in replacing the luminaire, but the affected area of the rig will still be left without a light for a period until the replacement arrives. At worst, the manufacturer will ask for the luminaire to be returned and inspected before any corrective action is taken, meaning the rig will be left without light for longer.

Either way, a significant period is likely to pass until light can be restored.

Modular Luminaire

With the ability to access the internal components (without risk of invalidating the certification), modular ex lighting can be serviced on-site by the rig’s engineers.

Furthermore, components of a modular Ex luminaire are interchangeable, meaning spare parts can be kept on-site to service the unit. This will allow the rig’s engineers to change the PSU/driver in a matter of minutes, and light can be restored quickly with minimum disruption to operations. Watch the video below as we demonstrate how quick the process is to change a PSU/driver on a SPARTAN Zone 1 Linear (the process is very similar if you are replacing a PSU on a Floodlight, Bulkhead or Bay luminaire).

With the understanding that a sealed for life luminaire must be returned to the manufacturer, in part 3 we will consider how this, and other features of a luminaire, can impact the environment.

Have a question about hazardous area lighting? Call us on +44 (0) 1670 520 055, or email Raytec Global at or Raytec Americas at

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