1 Scope

1.1 These requirements cover solid state circuit breakers (SSCB), and solid state hybrid circuit breakers (SSHCB) rated up to 1000 Vac and 1500 Vdc that switch using semiconductors and have integral galvanic isolation contacts. These devices are intended to provide service entrance, feeder, and branch circuit protection in accordance with NFPA 70^®, National Electrical Code^® (NEC^®). These devices may require auxiliary control power.

NFPA 70^®, National Electrical Code^®, and NEC^® are registered trademarks of the National Fire Protection Association, Quincy, MA.

1.2 This standard also covers solid state switches (SSCS) and solid state hybrid switches (SSHCS) rated up to 1000 Vac and 1500 Vdc.

1.3 These requirements are intended to be used in conjunction with the requirements in the Standard for Circuit Breakers, Switches and Circuit-Breaker Enclosures, UL 489, except as modified or supplemented by this Standard.

Summary of Topics

This is the First Edition of ANSI/UL 489I, Standard for Solid State Circuit Breakers, dated October 22, 2025. This standard covers solid state circuit breakers (SSCB), and solid state hybrid circuit breakers (SSHCB) rated up to 1000 Vac and 1500 Vdc that switch using semiconductors and have integral galvanic isolation contacts.