Industrial 71A8473-001D Autotransformer Ballast

Philips Advance 71A8473-001D Core & Coil Ballast Kit is a 400-watt High-Pressure Sodium ballast designed as a constant-wattage autotransformer (CW/CWA) for S51 lamps. This open-core, magnetic ballast supports quad-tap input voltages of 120, 208, 240, or 277 VAC at 60 Hz, enabling flexible installation in fixtures powered from different parts of the electrical distribution. Identified in catalogs as a Core & Coil HID ballast kit, the 71A8473-001D carries the ANSI code S51 (also listed as M169/S51 in some references), confirming compatibility with 400W S51 HPS lamps. As part of the Advance/Philips ballast family, it is intended for use in luminaires that require a 400W HID ballast with a core-and-coil design and a CW autotransformer configuration. Typical applications include lighting installations that require reliable 400W HID performance with multi-voltage operation, such as industrial, commercial, and outdoor fixtures that use HPS technology. The kit designation reinforces its role as a field-replaceable ballast component compatible with standard 400W S51 HPS lamps and common fixture configurations that accept Philips Advance core-and-coil ballasts.