Short answer: street lighting networks go dark again after an upgrade
mainly because of surge and driver failures where surge protection and earthing are inadequate,
deteriorated underground feeder cables and joints, water ingress at pole junction boxes, no
fault visibility without a control and monitoring system, and maintenance contracts written
without measurable service levels or an accurate asset register.
The complaint always arrives as a lighting complaint. It is usually a distribution
complaint. Understanding the difference changes what you specify in the next tender.
LED luminaires fail predominantly at the driver, and drivers fail predominantly from voltage
surges — lightning-induced transients, switching surges on the distribution network, and
sustained overvoltage on a loosely regulated rural feeder. Clusters of failures after a storm
are the signature. Protection requires surge protective devices at the feeder pillar
and appropriate surge immunity in the luminaire, plus an earthing system that gives
the surge somewhere to go. On many networks, the pole earthing is either absent or has corroded
away since installation.
A retrofit project typically replaces fittings on a network whose underground cable, joints
and junction boxes are decades old. Ageing cable insulation, poorly made joints and
water-filled pole boxes produce exactly what residents report: whole stretches out,
intermittent operation, and faults that return days after being “fixed”. Any serious street
lighting tender should include a condition survey of the existing cable and junction boxes, and
the rectification should be priced — not discovered later.
The pole junction box is the most abused component in the network: opened repeatedly for
maintenance, left unsealed, flooded during monsoon, and used as a jointing point for anything
that needs power. Specify properly rated and sealed boxes, cable gland discipline, loop-in
loop-out wiring with fuses, and a minimum height above likely flooding.
| Operating Model | How Faults Are Found | Typical Outcome |
|---|---|---|
| Manual switching, complaint-based repair | From residents and councillors |
Long outages; day burning in some wards |
| CCMS at feeder pillar | Automatic alerts at circuit level, with energy data |
Faster response; a fault is located to a feeder |
| Node-level control per luminaire | Pole-wise fault, burn hours and dimming data |
Targeted repair; verifiable uptime reporting |
A CCMS (Centralised Control & Monitoring System) does not make lights more reliable by
itself — it makes failures visible, which is what changes response time and makes a service
level enforceable.
Projects that fail usually have a strong specification for fittings and a weak one for
everything that happens after the inauguration.
Where a network is already failing, the sequence that works is: survey and geotag the real
asset base; test the existing feeders and junction boxes; rectify cable, joints and earthing;
install surge protection; standardise the luminaires and spares; add control and monitoring;
then put an SLA-based maintenance regime on top of a network that can actually meet it.
Reversing that order — new fittings onto an untested feeder — is why the second failure arrives
faster than the first.
VTPL executes street lighting, high mast and CCMS projects as an electrical EPC contractor,
treating them as distribution projects with a control layer — survey, feeder pillars, cabling,
earthing, surge protection, controls, installation, testing and maintenance. With 33+ years of
experience, 1,000+ projects and work for government bodies and urban authorities across 19+
states, our teams are used to working on live municipal networks.
The driver is usually the failure point, most often due to voltage surges and sustained
overvoltage where surge protection and earthing are inadequate — not because the LEDs
themselves have reached end of life.
That pattern points to a feeder-level problem: a faulty underground cable section, a failed
joint, a tripped or faulty feeder pillar circuit, or water ingress in a junction box — rather
than individual luminaire failures.
It does not prevent failures, but it detects and reports them automatically, which shortens
outage duration, eliminates day burning and makes maintenance service levels measurable.
A measurable uptime guarantee based on system data, defined response and rectification
times, spares and manpower commitments, preventive maintenance scope, platform and connectivity
cost ownership, and an updated asset register.
They should at least be tested. Retrofitting new luminaires onto deteriorated feeder cables,
joints and earthing is the most common reason an upgraded network fails again within a couple
of years.
VTPL delivers street
lighting, high mast and CCMS projects and urban distribution works for
cities and authorities. Talk to our EPC team
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