Keyoperated Automatic Transfer Switch Double Power Controller SLS3125B Available current ratings: 63A, 100A, 125A, 250A, 630A, 1000A Product overview This keyoperated automatic transfer switch provides reliable switching between two power sources for standby and dualsource power systems. Model SLS3125B is designed for controlled, keyprotected operation and is offered in multiple current ratings to fit a wide range of electrical installations. Key benefits Controlled changeover using a keyed mechanism to restrict unauthorized switching and allow intentional manual control when required. Automatic transfer function that detects source availability and transfers load to the alternate source to maintain power continuity. Wide current range from 63A to 1000A to support small residential loads through large commercial or industrial circuits. Simplifies connection and operation for systems that require a dedicated double power controller without complex external controls. Clear model identification: SLS3125B to help with selection and system documentation. Primary functions Monitor two power sources and perform automatic transfer between primary and secondary supply. Provide keyoperated manual control for authorized manual switching and lockout. Available in multiple amperage ratings to match load requirements and panel capacity. Compatibility and application notes Compatible with generator and utility mains configurations where a double power controller is required. Suitable for integration into switchboards, distribution panels, and generator control arrangements. Select the appropriate amperage rating to match protective devices and cable ratings in the installation. Performance and sizing guidance Choose from 63A, 100A, 125A, 250A, 630A, or 1000A versions to cover low to current requirements. Designed for use in systems that require dependable transfer logic combined with a keyed manual override. Confirm electrical parameters and installation space before selection to ensure correct fit and compatibility. Typical use scenarios Home standby power: Automatic transfer from utility supply to a backup generator for essential circuits during outages, with a key lock to prevent accidental manual operation. Small commercial building: Centralized transfer controller for switching lighting and HVAC loads between mains and generator, using the model and amperage that match the building load. Industrial or remote sites: Integration into a generator control panel or distribution board to manage primary and secondary feeds for equipment that requires coordinated switching. What to check before ordering Required continuous and peak load currents to select the correct amperage rating. Panel mounting and space constraints to confirm the SLS3125B can be accommodated. Compatibility with existing protective devices and the overall system wiring plan. This SLS3125B keyoperated automatic transfer switch offers a practical solution for controlled switching between two power sources across a broad range of current ratings.