Street Ligthting-u/g Faults

[brightidea]

What's the best trouble shooting practice when confronted with streetlights not working?

When approaching a streetlight with an apparent fault how is it confirmed with the power turned off?

How about an apparent fault on a circuit with power present?
example: 120vac streetlight is inoperable, the connections at the handwell show 120volts present, tested with a digital multimeter.

If 120vac is there, does that mean the street light is operational or not?

How do you confirm that the neutral is working?

Must a load test be done to ensure that the circuit is ok?

I am encountering several issues when it comes to underground streetlighting feeders.

could we engage in a discussion on this topic?
thanks,
brightidea

 

[tom baker]

You need to start at one end or the other.
I would start at the head.
Check voltage.
Assuming HPS,
you need to check
PE-Lamp-Starter-Ballast
If a twist lock PE, install a shorting cap
Easiest is to swap the lamp. if it was cycling, then its the lamp
to check ballast use a standard incandescent lamp, if the ballast is good then the lamp will light.
Starter is a bit harder to check. may be easier to install a new one.
Holophane makes a screw in tester, does all the above
We use cobra heads and will swap out the ballast door for a good one.
Most of the time its a lamp or starter.

Seldom is it a UG fault. You can verify this by check the wire insulation with a megger

 

[brightidea]

i am competant in trouble shooting fixtures, but not for faults on the feeders, especially where an underground padmount transformers are being used to supply the streetlight circuit, if i have a fault between the supply and the first fixture in the circuit, i have a very tough chore ahead of me.

who here has experience with locating faults and fault finding methods,
so far i find the most troublesome are open neutrals, or partially burnt off live legs.

i wish to engage in a discussion on best practices regarding streetlights,
we all can share and learn from eachother,

regards,
brightidea

 

[brian john]

Isolate the circuit and split the circuit.

Meg the cables.

If cables meg acceptable try to power lights, I generally seperate the lights to isolate the issue, bring up 1/2 the circuit with temp power (generator), then 3/4 circuit locatng lights that work and do not work..

Utilize fault location equipment to pinpoint fault, this takes some practice IMO you have to have faith in your equipment's fault finding abilities.

Locating faults is easier if you know the branch circuit route (DUH).