Connectivity Solutions for Single-Node Architecture Lighting Systems

Over a decade ago, most streetlights were incandescent with photocells to turn them off during daylight hours. The ANSI C136.10 Standard for Roadway and Area Lighting Equipment provided a common platform for the interchangeability of photocontrols and receptacles based on AC line voltage with 3-pole connections. In North America, the roadway and area lighting market developed ANSI C136.10 as the standard interface, while it became the de facto standard in much of the world.

As energy costs have risen and LED technology has become more prevalent, ANSI C136.41 was developed to define devices and receptacles for increasing the efficiency of roadway luminaires. Created to be backwards compatible with existing lighting systems, this standard maintains the 3-pole line voltage connection and adds contacts for signal output. This interface allows for either digital or analog dimming control by a photodiode and an Astro-clock or motion sensor.

The architecture is designed to have grid power routed into ANSI C136.41 photocontrol and will switch that power to the LED driver. An internal power supply unit (PSU) converts that grid power to a logical voltage to power the controls. Often in North America, the dimming signal is analog (0-10 V) which is perceived to be inexpensive and reliable. Networking of the streetlights is achieved through a variety of different wireless protocols.

The ANSI C136.41 Standard does not provide many details about how to include sensor inputs into luminaires. The wide variety of wiring configuration choices makes it challenging to optimize components. Also, the 0-10 V analog control output limits the lighting fixture to only one input. However, there is considerable effort to include the D4i protocol, based on DALI-2, in future standard updates to address this.