UL to launch accelerated thermal evaluation service

Apr. 23, 2016 – Safety test provider Underwriters Laboratories (UL) is launching a shorter 50-day electrical insulation system test program for electric motors at the forthcoming CWIEME Berlin exhibition in response to the “global demand from manufacturers for help getting products to market quicker without compromising on safety,” it says.

“A lot of our customers have been asking for a way to shorten the time needed to test their insulation systems,” says Mark Raymond, principal engineer at UL. “This 50-day program can help them bring their products to market quicker especially, for example, if they make a tweak to the motor design at a later stage in development with a new combination of insulating materials as they won’t have to wait a whole year to get the product certified.”

The heat generated during the operation of a magnetic device — whether an electric motor, generator or transformer — naturally leads to degradation of the insulation over time. It is critical to understand how this thermal aging takes place as a failure in the insulation may lead to fire, injury or electric shock, says UL. Electrical insulation components are often issued their own individual thermal ratings – the maximum operational heat they can withstand – but it is the way these components perform in combination that is a true measure of the safety and reliability of the device, it notes.

“Insulation materials behave differently in combination,” explains Raymond. “And there are also many different combinations you can have – so it is essential for manufacturers to carry out long-term thermal ageing tests on the integrity and performance of the entire electrical insulation system for their own confidence in the safety of the product as well as their customers’.”

UL says it can also help customers launch products quicker by issuing a provisional certification if, during a long-term test program, all trends are pointing towards the desired temperature rating. This would allow the manufacturer to start a production run under the understanding that the final rating may change, it says.

The 50-day test for electrical insulation performance in electric motors, although new for UL, is not entirely new in the industry. The method has been described in the IEC (International Electrotechnical Commission) standard 60335 (annex C) for several years but this is the first time that UL is offering it.

“UL has long been thought of as a gateway to the North American market for foreign manufacturers. We’ve listened to the needs of the market and by working from international test methods, we are able to improve the transparency, relevancy and convenience of our tests,” Raymond says.

The conference takes place May 10-12 in Messe Berlin.