Short answer
One pole light out or cycling on and off usually has a failing lamp or ballast, most often an aging metal halide or high-pressure sodium lamp. All the lights out, or on all day, points to the photocell, time clock or lighting contactor. A group of poles out can mean damaged underground wiring. A pole hit by a plow or vehicle should be treated as unsafe. LED retrofits solve many of these problems for good.
What's Probably Happening
Parking lot lighting has three parts that fail: the fixtures on the poles, the controls that turn them on and off, and the wiring that runs underground between them. The pattern of what's out points to which one.
End-of-Life Lamps Cycling
Metal halide and high-pressure sodium lamps don't just burn out. Near the end of their life, they often cycle: the lamp lights, runs hot, shuts itself off, cools, and restarts a few minutes later. Sodium lamps may also turn pink or orange and dim before failing. One or two fixtures behaving this way is almost always a lamp or ballast.
Failing HID Ballasts
The ballast in each fixture starts and regulates the lamp. Heat, cold and years of use wear them down. A fixture that stays dark with a new lamp, or cycles even with a good lamp, usually has a bad ballast or igniter.
Photocells, Time Clocks and Contactors
When every light is out, or every light is on at noon, look at the controls. A photocell can fail, get dirty, or get fooled by light from a nearby fixture. A time clock can lose its settings after a power outage. A lighting contactor can stick closed or fail to close. These are usually quick fixes once found.
Damaged Underground Feeders
If a string of poles goes dark together while others work, the wiring between them may be damaged. Frost heave, digging, landscaping, and old wire insulation breaking down in wet soil all cause underground faults. These may also trip breakers repeatedly.
Pole and Base Damage
Snowplows and vehicles hit light poles, especially in winter. A bent pole, a cracked concrete base or a knocked-loose handhole cover can leave wiring exposed and the pole unstable.
What You Can Safely Check Yourself
- Note which poles are out, cycling or on during the day. A quick sketch of the lot helps.
- Check whether the problem started after a power outage. If so, the time clock may need resetting.
- Look for a tripped breaker on the lighting circuit and reset it once, without opening the panel cover.
- Walk the lot in daylight and look for damaged poles, cracked bases, open handhole covers or exposed wire. Don't touch anything you find.
- If lights stay on in daylight, check whether something is shading the photocell or whether it was recently moved.
When to Stop and Call
- A pole is bent, leaning, or has a damaged base: keep vehicles and people away from it.
- Wires are exposed at a pole or handhole: keep everyone clear and don't touch them.
- A group of poles is out and the breaker won't stay on.
- Fixtures cycle or stay dark after relamping.
- You're tired of lamp and ballast replacements and want to price an LED retrofit.
Select Electric does parking lot lighting installation and maintenance, from single-fixture repairs to full LED conversions, and is a Consumers Energy Trade Ally, so rebates may be available for qualifying upgrades. Call (989) 835-3587 and tell us which poles are out and what they're doing.
Common Questions
Why do my parking lot lights turn on and off by themselves?
A metal halide or high-pressure sodium lamp near the end of its life often cycles: it lights, overheats, shuts off, cools and tries again. A failing ballast or a photocell that sees light from the fixture itself can cause cycling too.
Why are my parking lot lights on during the day?
A failed or dirty photocell, a time clock that lost its setting after an outage, or a stuck lighting contactor can all keep lights on in daylight. Checking the controls usually finds it.
A plow hit one of our light poles. Is it safe?
Treat it as unsafe until it's checked. A damaged base can let the pole fall, and the wiring in the base or handhole may be exposed. Keep people and vehicles away, and call an electrician. If wires are exposed or the pole is down, keep everyone clear.
Is it worth converting to LED?
Often, yes. LED fixtures use less energy, last much longer than metal halide or sodium lamps, and turn on instantly without the warm-up and cycling problems. Rebates may be available through Consumers Energy for qualifying upgrades; Select Electric is a Consumers Energy Trade Ally.