WAUCONDA, IL — Delta-Therm Corp., a manufacturer of electric heating systems, recently supplied mineral-insulated (MI) cable for a parking garage application in response to a change in the National Electrical Code (NEC).

MI cable is now the only cable available for snow melting and deicing that is exempt from ground-fault protection when embedded in a noncombustible medium such as concrete or asphalt, the company said.

The 1999 NEC exempted MI cable from the 1996 code that had required all snow-melting and deicing cables to be ground fault protected. As ground fault protection of equipment (GFPE) for large snow-melting projects is expensive, costing roughly $300 per circuit, the NEC exemption significantly reduces project costs, said the company.

GFPEs also need to be manually reset after they are tripped, the company pointed out. Many times, tripped GFPEs are not detected until it’s observed that the system isn’t functioning correctly, causing further setbacks and maintenance.

Siva K. Haran, project manager and senior electrical engineer at Teng & Associates Inc., learned of the change in the NEC and determined that MI cable would be the most efficient and economical choice for heating the parking garage located in Des Plaines, IL. Three vehicular concrete ramps were outfitted with the cable.