Street Light Supply Voltage

[J.B. Wood]

Hello, and I'm sure an easy question for those electricians employed by
electric utilities:

Are traditional (mercury vapor bulb or sodium bulb) pole-mounted public
street/highway luminaires in the U.S. powered by 12O VAC or 240 VAC or
does a single fixture require both (for the lamp, ballast and
photocontroller)? Thanks for your time and comment. Sincerely,


--
John Wood (Code 5520) e-mail: [email protected]

Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

 

[Josepi]

Always 120Vac, in Canada. The USA will be the same bulbs.

They want a neutral outside bulb connection that is grounded, same as in
your home fixtures.

The photo relays and other equipment is all 120V


Hello, and I'm sure an easy question for those electricians employed by
electric utilities:

Are traditional (mercury vapor bulb or sodium bulb) pole-mounted public
street/highway luminaires in the U.S. powered by 12O VAC or 240 VAC or
does a single fixture require both (for the lamp, ballast and
photocontroller)? Thanks for your time and comment. Sincerely,


--

 

[James Sweet]

Hello, and I'm sure an easy question for those electricians employed by
electric utilities:

Are traditional (mercury vapor bulb or sodium bulb) pole-mounted public
street/highway luminaires in the U.S. powered by 12O VAC or 240 VAC or
does a single fixture require both (for the lamp, ballast and
photocontroller)? Thanks for your time and comment. Sincerely,

Residential neighborhoods are usually 120V, arterials are mostly 240V
but 120 and 480 can be found from time to timem and highway street
lighting is usually 480V. There are also high voltage series
installations still in use in many parts of the country, although they
are gradually being replaced. Those use a mechanical constant current
regulator to drive a high voltage loop at 6.6 Amps, traditionally using
special incandescent lamps but isolation transformers for HID lamps
exist and are widespread in series areas.

In all cases, the photocell will be matched to the voltage of the
luminaire when individual photocontrols are used. Highway lighting
normally control large groups of luminairs with a single photocontrol
and contactor, and series installations are always controlled from the
regulator and can have hundreds of luminaires in a single loop.