3.8 High Temperature (or Floodlight) Controls

The current ANSI photocontrol standard (C136.10-1996) calls for photocontrols to operate at ambient temperatures of up to 65°C (150°F) with a base receptacle interface temperature of 90°C (194°F) maximum. The problem is that some 1000 watt metal halide and mercury vapor flood lights heat the control receptacle to over 100°C (212°F). A major utility reported to the ANSI committee an actual field reading of 115°C (239°F) at the control receptacle. Clearly there are problems when a device designed for 90°C maximum is heated to 115°C.

Therefore, utilities using larger wattage flood lights should consider using the special, high temperature floodlight controls. Such controls are rated for higher base temperatures. These controls use silicon sensors since CdS cells drift rapidly when heated over 75°C (168°F). High temperature controls are typically specified with higher turn-ON levels, such as the IES recommended 2.6 footcandles (27.9 lux), to prevent reflected light from the high lumen output fixtures from affecting the control. Finally, all floodlight controls should have a 2-5 second turn-OFF delay to prevent unwanted switching and the resultant wait for lamp cool down and re-strike.

Remember: A true high temperature, flood light control needs to have more than just better plastic. It needs:
- Higher turn ON level like 2.6 ftc (28 lux)
- Close positive OFF/ON ratio like 1.5:1
- Identifying cover color. Many utilities use brown.
- Silicon sensor
- High temperature components
- Neoprene or similar gasket