Lighting issues can disrupt operations and create safety hazards in commercial buildings. As the facility manager, I need to be able to efficiently diagnose and repair broken light fixtures to keep the building functional. This guide will provide an in-depth overview of troubleshooting the most common problems with commercial light fixtures so I can get them working again quickly.
Inspecting the Light Fixture
The first step is always to visually inspect the problematic light fixture and identify any obvious issues. Here are three key things to check:
Check for Broken Bulbs
If the light bulb is not turning on, the first thing to check is if the bulb itself is broken or burned out.
-
Examine the bulb for any cracks or damage. Gently remove the bulb and look at the filament inside. If the filament is broken, the bulb needs replacement.
-
Check the type of bulb and its rated life hours. Fluorescent bulbs last 10,000-20,000 hours while incandescent bulbs are 1,000-2,000 hours. The bulb may simply be at the end of its usable life.
-
For fluorescent fixtures with multiple bulbs, remove each bulb individually and test which one is not working. Replace only the bad bulb(s).
Check Electrical Connections
Loose wiring or electrical connections can cause lights to flicker or not turn on.
-
Check that the bulb is properly seated in the socket. If it's loose, tighten it or adjust the contacts.
-
Inspect the wires and connectors inside the fixture. Re-secure any loose wiring connections with electrical tape or wire nuts as needed.
-
For fluorescent fixtures, check that the tombstones are making good contact with the pins on the bulb ends.
Look for Signs of Damage
Cracks, dents, or other physical damage to the fixture can result in light issues.
-
Examine the lens, reflector, housing and other components for any cracks or damage.
-
Check for signs of corrosion which can prevent electrical connectivity.
-
Ensure the mounting hardware and brackets are still secure and not broken or bent.
Testing the Electrical Circuit
If the bulb and connections check out but the light still does not work, the next step is testing the electrical circuit for power. Here are two ways to test:
Use a Voltage Tester
A non-contact voltage tester is a quick way to check for power in the light circuit.
-
With the light switch on, hold the voltage tester tip near the wire connections and socket inside the fixture. If the tester does not light up, there is no power present.
-
Turn off the light switch and repeat the test at multiple points along the wiring back to the junction box. This helps isolate the location of the electrical problem.
-
Check the circuit breaker for the lights and reset it if tripped. Circuit breakers sometimes will not show as tripped and need resetting anyway.
Use a Multimeter
For a more thorough test, use a digital multimeter set to measure AC voltage.
-
With the light switch on, touch the multimeter probes to the hot and neutral wires in the light fixture. A reading of 120-240V indicates power.
-
If voltage is lower than expected, there may be a wire with high resistance causing voltage drop. Check connections for corrosion.
-
If no voltage at all, trace the wires back to check each junction point until finding the point of power loss.
Troubleshooting the Fixture and Ballast
For fluorescent fixtures that use a ballast, problems with the ballast itself can cause operation issues. Here's how to troubleshoot:
Listen for Hum or Flickering
A failing or defective ballast may produce noise or make the bulbs flicker.
-
Turn off nearby equipment and listen closely to the ballast. A soft humming is normal but loud buzzing indicates problems.
-
Observe bulb operation when turning on the fixture. Excessive flickering points to ballast issues.
Check Ballast Wiring
Loose wiring in the ballast can disrupt bulb operation.
-
Inspect wiring connections to the ballast and secure any loose wires.
-
Check that all ballast wires are connected to the right contacts per the wiring diagram. Verify the wiring order.
-
Replace any deteriorated wiring going into the ballast. Use new 18-24 AWG wires suitable for the ballast ratings.
Replace Defective Ballasts
If a ballast is making excessive noise, gets very hot, or still does not operate properly after wiring checks, then it likely needs replacement.
-
Match the ballast specifications and type - voltage, power level, number of lamps.
-
Consult wiring diagrams to ensure correct wire connections to the ballast during replacement.
-
Properly dispose of old ballasts which contain hazardous materials.
When to Call an Electrician
In some cases, the services of a licensed electrician may be needed to safely address the root cause of fixture issues. Consider calling an electrician for:
-
Light problems where power wiring issues are suspected. Diagnosing and safely working on building wiring requires proper training and expertise.
-
Multiple fixtures on the same circuit are not working, pointing to a circuit breaker, wiring, or power supply issue.
-
The light fixture requires disassembly of high voltage components. Ballasts, capacitors, and power connections can hold dangerous residual voltage if not discharged properly.
-
Older fixtures where wiring does not match modern electrical code. Outdated wiring needs professional evaluation and upgrades.
-
The facility's insurance policy or regulations require that a licensed electrician perform repairs or replacements of building lighting and electrical systems.
By methodically troubleshooting light fixture issues using these steps, I can solve many common problems encountered in commercial building lighting systems. When more complex electrical issues arise, consulting a qualified electrician helps ensure repairs are completed safely and correctly. With diligent fixture inspection, testing, and maintenance, I can keep the lighting running optimally across the commercial property.