Schneider Electric 9810ST400 Capacitor Power Supply

Schneider Electric's Square D 9810-ST-400 Sure-Trip Capacitor Power Supply provides the dedicated DC energy source that powers Sure-Trip capacitor trip units used in Square D protective equipment. This unit accepts 240/480 VAC input and stores 45 joules of energy to feed a capacitor-based trip circuit, delivering a loaded output of 150/177 Vdc and a no-load output of 68–95 Vdc, with a defined trip voltage of 82 Vdc to ensure fast, reliable protection. As part of the Class 9810 family, the ST-400 variant is designed specifically to power ST-400 capacitor trip units, making it suitable for legacy Square D switchgear, motor control centers, and other industrial protection panels where capacitor-discharge tripping is required. The device is intended as a replacement or service part for equipment that originally used the 9810-ST-400 power supply, ensuring compatibility with Square D 9810 Class devices and their installation footprints. Because it is a high-energy safety component, installation and maintenance should be performed by qualified personnel following applicable codes and the equipment's manuals.