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Expanded Temperature Testing for HazLoc Control Panels

Supporting certification of extended ambient temperature to 60-plus degrees Celsius.

A hazloc panel in UL lab

November 26, 2020

Today, due to the decrease in size of controls being manufactured and increase in heat dissipation as well as ambient temperatures, the risk for manufacturers of costly control failures has increased. UL has now extended the ambient temperature range to +60°C for certifications of industrial control panels for use in hazardous locations within our standard offering.

Industrial facilities continue to focus on plant optimization, while at the same time, they are being built in more extreme climates. In addition, control panel manufacturers continue to design and produce smaller enclosures with more densely packed components leaving little room for heat dissipation – this can create an increase in control failures. When these panels are installed in countries near the equator, or in other locations with high ambient temperatures, these problems are compounded  So, understanding not only the size of the panel but also its’ intended application can have an impact on the requirements needed to be met. Ambient temperature ratings are vital to correctly determine whether a panel, with the necessary components inside, can safely operate in a specific application and the surrounding environment.

Manufacturers will identify a range of safe operating temperatures for equipment intended for use in hazardous locations. A default range of 20°C to +40°C can be used when no other range is specified. Components installed within an enclosure can add a layer of complexity due to self-heating of the internal components. This is due to the enclosure trapping heat generated inside causing internal temperatures to be higher than the external atmosphere. The best way to determine this variance in temperature is by testing the assembled control panel. Because of the variety of factors involved, the maximum ambient temperature must be considered during testing.

As a result of demand in industry, UL has now extended the ambient temperature range for certifications of industrial control panels for use in hazardous locations. Through this expanded certification, purged and pressurized panels and Division 2 panels can now be certified up to a +60°C ambient temperature under UL’s standard offering. “Addressing customer needs is our top priority and we are pleased that UL’s experts could expand our coverage to a wider range of ambient temperature ratings for industrial control panels.  This will minimize cost for manufacturers while helping to ensure the same level of safety,” said Michael Slowinske, engineering manager, Energy and Power Technologies division at UL.

In addition, we are also able to certify other ratings (beyond 60°C, for example), or additional types of explosion protection for hazardous locations by completing a special engineering investigation. We continue to listen to customer feedback as we work to expand our capabilities to provide a total solution for the evolving needs our customers. For more information, learn more about our hazardous locations testing capabilities.