Discover the Technical Note

The National Electrical Code® (NEC) requires Transfer Switching Equipment (TSE) to be UL 1008 Listed by Underwriters' Laboratories and carry the UL 1008 label.

The UL Listed TSE can be used in standby systems described in NFPA 70 (National Fire Protection Association), and has to conform to the applicable requirements of UL 1008, NEMA ICS 1, and NEMA ICS 2.

In this technical note, we will focus on Articles 700, 701, and 702 of the NEC; these Articles describe the electrical safety of the installation, operation, and maintenance of emergency systems, including specific requirements for TSE.