High voltage circuits are “series” circuits, not “parallel.” When a high voltage street light circuit fails, the street lights for the entire neighborhood have to be shut off. This is for safety, while troubleshooting and repair tasks are completed.
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You may report any outages to our Traffic Electrical division at 209-342-2297.
Typically when street lights fail, it is due to one of several simple reasons that may occasionally affect our newer, more modern, low voltage street light circuits. The most recent streetlight failures are occurring on a few of our 29 high voltage circuits which are much older, more complex to fix, and more likely to fail.
Due to the age of the wiring, the method of installation, and the higher voltage, the wires are now “going to ground.” This means that the insulation covering the wire has deteriorated to the point that it no longer contains the electricity as efficiently as it did when it was installed many years ago. This results in further damage to the insulation which will ultimately create more failures.
High voltage (HV) circuits, which are decades old, operate between 2400 and 4000 volts. This is hot enough to turn dirt into glass. (As a comparison, modern lighting is only 120- 277 volts.) Originally, the wiring was laid in a trench, without a conduit. This is known as “direct burial wire.” These wires only have one conductor, unlike modern circuits which have two conductors.
Because the units are so old, they may fail immediately after being fixed, requiring additional repairs. Vandalism and anti-theft measures installed on city streetlights has also increase the repair time. A total of 7 electricians are responsible for troubleshooting, and repairing 11,035 streetlights in Modesto, as well as maintain:
The LED streetlight upgrade program did not include the replacement of HV circuits and streetlights. This is because existing LED luminaires do not work above 480 volts. The infrastructure of HV circuits needs to be replaced with low voltage circuits. This will include installing conduit, pull boxes, wiring, and other infrastructure. At that point, LED luminaires could be installed.
The cost of upgrading all 29 HV circuits and infrastructure is approximately $6 million.
Yes, on February 26, 2019 City Council approved a program to fund $1,000,000 a year as a result of Senate Bill (SB), and Gas Tax funds to replace these street lights to low voltage. The Estimated time frame to complete this project is four to five years.