SQUARE D Switch Interlock Kit 100A-200A

Electrical Interlock Kit

The Square D electrical interlock kit is designed for field installation on heavy-duty safety switches rated between 100 and 200 amperes. It provides a mechanical link that prevents two switches from closing simultaneously, ensuring safe source transfer. The kit includes a pivot arm that operates directly from the switch mechanism to break the control circuit before the main blades separate. All components and mounting instructions are supplied for on-site assembly.

Capacity and Headroom

This accessory is built specifically for switches carrying 100 to 200 amperes, matching the interrupting capacity of the host enclosure. It adds no additional current-carrying parts, so the system headroom remains defined by the switch rating itself. The mechanical interlock function is effective across the full operating range of the compatible safety switches. Installers must verify that the host switch falls within the stated amperage window before fitting the kit.

UL Listed Safety Standard

The kit carries a UL listing, confirming it meets the relevant safety requirements for electrical interlock devices. Compliance is limited to the mechanical interlock function and does not extend to the switch's short-circuit withstand rating or control-circuit voltage. Field installation must follow the supplied instructions exactly to maintain the listing. Any modification or use outside the specified switch ratings voids the certification.