UL 1400 is a series of standards developed by UL Solutions to address the safety and performance requirements of Fault-Managed Power Systems (FMPS), also known as Class 4 power systems. These systems are designed to monitor circuits for faults and control power transmission to ensure that energy delivered into a fault is limited, thereby enhancing safety against electric shock and fire hazards.

The UL 1400 series comprise multiple parts, each focusing on different aspects of FMPS:

• UL 1400-1: This part specifies safety requirements for FMPS equipment. It was first published on December 19, 2022, and outlines criteria for the design and performance of FMPS transmitters and receivers. The standard ensures that these systems can detect and respond to faults effectively, maintaining safety in various operational conditions.

• UL 1400-2: This part focuses on the requirements for cables used in FMPS. Published in August 2023, UL 1400-2 covers specifications for single- and multiple-conductor, jacketed cables intended for fixed wiring within buildings, as well as for outdoor and direct burial applications in Class 4 circuits. The standard includes classifications for different cable types, such as CL4P (plenum cables), CL4R (riser cables), CL4 (general-purpose cables), and CL4Z (outdoor-use-only cables). It also addresses performance criteria like fire resistance, temperature tolerance, and durability to ensure that cables maintain integrity under both normal and fault conditions.

This presentation will focus on the status of both standards, including updates, and future developments.