HPS Ballast Cross Reference:
Advance 72C8185NP
Sylvania LU150/120/277/F-CAN (47765)

Universal Ballast 12210241CTC, Replacement F-Can HPS Ballast Kit for 150 Watt High Pressure Sodium.  This F-Can HID Ballast is designed with a Circuit Type HX-HPF, for one 150 watt HPS Lamp, S55 ANSI Ballast Type, 185 Input Watts, 120/277 Input Voltage, 60 Hz. 

The maximum distance this F-Can ballast can be mounted from your 150 watt high pressure sodium bulb is 10 feet. It has a sound rating of B and is UL and CSA Certified. For proper installation, insure that remote ballasts are properly vented and mounted to a heat-dissipating surface.

Specification Sheet