The National Electrical Manufacturers Association has published ANSI C136.41-2013 For Roadway and Area Lighting Equipment–Dimming Control Between an External Locking Type Photocontrol and Ballast or Driver.

This standard describes methods of light level control between an external locking type photocontrol (or similar device) and a dimmable ballast or driver for street and area lighting equipment.  Mechanical, electrical, and marking requirements are established for dimming, locking type photocontrols and mating receptacles.  All requirements of ANSI C136.10-2010, for photocontrols and receptacles, shall apply except where specifically superseded by this standard.

ANSI C136.41-2013 For Roadway and Area Lighting Equipment–Dimming Control Between an External Locking Type Photocontrol and Ballast or Driver may be purchased in electronic or hardcopy format on the NEMA website or purchased in hardcopy.