Visit the Lenze web site

Changing standard affects electric panels

An UL International (UK) product story
Edited by the Engineeringtalk editorial team Aug 15, 2007

New UL standards came into effect in march 2007, and training days are being organised covering the new directions.

Underwriters Laboratories (UL) have announced important alterations to the UL508A standard (Industrial Control Panels) which concerns the production of industrial electric panels.

The UL 508A standard certifies that the assembly of all electric panel components (size and design testing) conforms to US standards as mandated by the National Electric Code (NEC), the chief regulatory benchmark source for the American system.

The NEC is revised every three years: between 2005 and 2006 new electric panel guidelines were issued.

Each part of the standard, which came into force in April 2006, lays out the benchmarks for working out short-circuit current calculation of electric panels with particular attention to the solutions for elevating that value (the use of F type combination motor controllers and current limiting fuse wires or circuit breakers).

UL is the only agency recognised by NEC which has a valid system for calculating short-circuit current.

Another important change regarding componentry is that it is necessary that electromagnetic filters are presently equipped with short-circuit current calculation.

Other fundamental changes regard cable dimensioning for internal wiring.

The absorption table for cables has new values.

There has already been a change to the standards on interlock types permitted and their requirements relative to internal movement of the general switch.

The last updates were issued at the end of 2006 and the new requirements came into force in March 2007.

Throughout the year, Underwriters Laboratories are organising training days in order to make the new directions known, and the results from the update to the rules and their impact on the way electric panels are designed and manufactured, in conformity with the UL508A standard.

Find out more about this article. Request a brochure, download technical specifications and request samples here.

Not what you're looking for? Search the site.

Back to top Back to top

Contact UL International (UK)

Tel +44 1483 402010

Other UL International (UK) stories

Newsletter sign up

Request your free weekly copy of the Engineeringtalk email newsletter ...

Visit the Lenze web site

Browse by category

All suppliers A - Z

A Pro-talk Publication

A Pro-talk publication