Street Lights

Streetlight System

The City owns and operates a streetlight system that contains over 4,000 streetlights across 74 zones called streetlight planning areas.  Each planning area contains one or more streetlight circuits.  Nearly 45% of the streetlight system has been converted to LED in where the street light conduit, wiring and lights were replaced and upgraded.  The LED streetlight system is energy efficient, provides increased lighting levels and visibility, while being more reliable and low maintenance.  The remaining system is on high voltage series streetlight circuits with high-pressure sodium lighting which were designed and installed approximately nine decades ago.  These streetlights have issues of reliability due to their age and condition making their maintenance an expensive and time-consuming process.  The estimated cost to upgrade them to LED is estimated at over $28 Million due to the need to replace the conduit, wiring and streetlights for which funding is not available.  While the City owns and maintains the majority of the lights, over 400 lights are owned and operated by Southern California Edison (SCE). View a map(PDF, 550KB) of series streetlights in the City of South Gate.

Streetlight System Outages

The outages experienced in the streetlight system are due to system failures or power outages.  The City is responsible for addressing system failures on the streetlights it owns which typically requires troubleshooting, conduit repairs and rewiring.  Non-complex failures are handled by City staff and repaired within two weeks.  Complex failures require the support of a specialty contract and typically take up to four weeks to repair.  There are however some reasons repairs may be delayed.  The Electrical Division does its best to repair most streetlights, but sometimes repairs may take longer from a few days to a few weeks.  The impact of these outages can range from a few lights to several lights when an entire circuit is out, and multiple streets are impacted.  We may need to order special repair parts which can take weeks.

Electrical power for streetlights is provided by SCE.  Outages caused by SCE power failures can be complex and take an extended amount of time to complete.  If the problem is with the power system, repairs depend on SCE’s crew availability. Further, the repair process is iterative requiring troubleshooting both the streetlight system and the SCE power supply system, SCE procurement, and SCE repairs, which can take over four weeks to complete.  The schedules for SCE repairs are based on the type of failure.  A common failure is of the Regulated Output (RO) transformers.  The series streetlight system relies on RO transformers which are difficult to repair or replace, according to SCE.  These transformers use a system of weight, magnets, and coils, to compensate for changes in load when lamps fail.  RO transformers for some of the older lighting systems are no longer manufactured and must be refurbished.  Refurbishing is a manually intensive operation which relies on re-using a system of weights, magnets, and coils.  Therefore, rebuilding an outdated transformer can take two to three months, and these are costly to refurbish.  If SCE can’t repair the transformer, they must order one to be specially rebuilt and installed. The City has been working with SCE to have as many transformers in stock as possible for immediate installation. However, there is a variety of transformer types, and their availability cannot be guaranteed.  As such, outages caused by SCE power outages could take over four weeks to complete.  Furthermore, at times, power outages cause damage to the streetlight system, thus, after power is restored, up to an additional two to four weeks may be needed to repair the streetlight system.

Streetlight Series Circuit Explanation

The series circuit streetlight system is less reliable than the streetlight system that has been converted to LED.  Nine out of every ten outages occur on the series circuit streetlight system.  Streetlights on series circuits use a constant current, variable voltage source to supply electricity to lights connected to the circuit in a loop. There are three components to a series lighting circuit: constant current regulator, isolation transformer, and series circuit wiring.  The constant current regulator supplies electricity to the series circuit. The isolation transformer is the connection for the lights in a series circuit and regulates the electric current between lights. Series circuit wiring is a single wire loop that connects the power source to the lights one by one and wraps around to return to the power source.

There is only one flow of electricity in series lighting. The current enters the first light and powers the lamp, and then flows to the next light in a series. The electric current flows in one direction in the series until all lights are supplied with energy. If one connection in this path is broken, then the circuit is broken and all the lights in the series will not work. Essentially, series lighting is the same as old Christmas tree lights - if a single light (connection) anywhere in the series goes out, then the rest of the lights in the series will not work.

Reporting Streetlight Outages

Public Works' Electrical Division is responsible for repairing streetlights on public streets.  If you notice a streetlight on a public street is malfunctioning, you can report it by calling Public Works General Maintenance/Electrical Division at (323) 563-5795 during normal business hours, Monday – Thursday, 6:30 am – 5:00 pm. For after-hours calls to report street light circuit outages, residents and businesses may call SGPD, at (323) 563-5436.

To prioritize safety while repairs are being completed, mitigation measures are implemented such as increased patrolling by SGPD, temporary repairs to activate as many impacted streetlights as possible, and/or deploying mobile light towers when outages are anticipated to take more than three weeks to repair and restore.  Mitigations are selected on a case-by-case basis and in consideration of the extent and time of impacts required for repairs.

Public outreach such as door hangers is also a part of the repair process to ensure residents and businesses are informed.

Regardless of the time it takes to repair a streetlight, we do our best to keep our customers updated on repair status.  If you have placed a repair request and the streetlight has not been repaired within 10 working days, please feel free to call Public Works at (323) 563-5786 to get an update on your request’s status.

Streetlights on Private Streets and SCE-owned Streetlights

If you live on a private street, the streetlights are probably maintained by SCE.  Also, streetlights mounted on wooden power poles are usually owned and maintained by SCE as well. You may call SCE at (800) 611-1911 for repairs.