How to Troubleshoot and Repair Commercial Lighting Systems

How to Troubleshoot and Repair Commercial Lighting Systems


Maintaining a properly functioning lighting system is crucial for any commercial building. As the owner or facilities manager, it's important to understand how to troubleshoot and repair issues with commercial lighting to keep your building illuminated and avoid disruptions to your business. In this guide, I will provide an in-depth overview of commercial lighting systems and give step-by-step instructions for diagnosing and fixing common problems.

Types of Commercial Lighting Systems

There are three main types of lighting systems used in commercial buildings:

Fluorescent Lighting

Fluorescent lights are long tubes that contain mercury vapor. When electricity excites the mercury, it creates ultraviolet light that causes a phosphor coating inside the tube to glow. Fluorescent lights are energy efficient and inexpensive, making them a popular choice for office buildings, schools, hospitals, restaurants, and retail stores. The most common issues with fluorescents involve failing ballasts or burnt-out bulbs.

LED Lighting

LED (light-emitting diode) lights use semiconductors to emit light efficiently. LEDs use up to 80% less energy than traditional lighting and can last up to 50,000 hours. They are often used for spot lighting and increasingly for overhead lighting. LED fixtures contain driver circuits that can fail over time and need replacement. The LEDs themselves can also degrade and dim.

High-Intensity Discharge (HID) Lighting

HID lighting includes mercury vapor, metal halide, and high-pressure sodium lights. They produce bright, energy-efficient light by sending an electrical discharge through a gas-filled tube. HIDs are commonly used in warehouses, gymnasiums, and outdoor areas. They require ballasts to regulate the current. Faulty ballasts account for many HID lighting problems.

Checking for Basic Lighting Issues

When commercial lights are out or acting abnormal, start troubleshooting by checking for these basic issues:

Troubleshooting Fluorescent Lighting

Fluorescent lights have a ballast that regulates power flow and electrodes at each end that excite the gas in the tube. Here are tips for finding and fixing common fluorescent lighting issues:

1. Check for Proper Voltage

Use a multimeter to check power at the fixture. Lack of proper voltage can cause intermittent operation or failure to light.

2. Test the Ballast

Ballasts can overheat, short circuit, or lose power due to old age. Use a ballast tester to verify proper operation. Replace defective ballasts.

3. Replace Non-Functioning Bulbs

If the ballast is good, flip tubes end-to-end or swap into adjacent sockets to check for bad bulbs. Replace spent fluorescent tubes.

4. Check Lampholders

Broken lampholders can sever the connection between the ballast and tube. Inspect lampholder pins for damage. Replace lampholders as needed.

5. Clean Fixture Contacts

Buildup of dirt, grease, and oxidation on fixture contacts can inhibit connections. Clean thoroughly with electrical contact cleaner.

6. Retighten Wiring Connections

Loose wiring causes high resistance and voltage drop. Turn off power and inspect wiring for loose screw terminals. Tighten all connections.

7. Bypass or Replace Starter

Starters help ignite fluorescent tubes. If bulbs flicker, test the starter and bypass or replace if faulty.

Troubleshooting LED Lighting

LED lighting failures typically involve the driver (power supply) or degradation of the LED components. Here are tips for diagnosing LED problems:

1. Verify Input Voltage

Use a multimeter to check input voltage at the driver. Low voltage can cause intermittent operation or premature driver failure.

2. Check for Faulty Drivers

Drivers convert and regulate voltage for the LEDs. If LEDs are out, test the driver and replace if faulty.

3. Check for Overheating

Heat sinks and thermal management help prevent overheating. If the fixture overheats, improve ventilation or upgrade heat sinking.

4. Replace Defective LED Modules

LEDs slowly degrade over time. Replace individual LED modules if light output is significantly reduced.

5. Reflow Solder Joints

Loose solder joints on driver components or LED boards can cause flickering and reduced light output. Reflow all solder joints.

6. Clean LED Lenses and Housings

Dirt buildup on optical components causes light loss. Clean lenses and housings regularly to maximize light output.

Troubleshooting HID Lighting

HID lighting relies on ballasts, capacitors, and ignitors to operate properly. Here are tips for troubleshooting HID fixtures:

1. Check Capacitor

A faulty capacitor can prevent HID fixtures from starting. Test the capacitor and replace if bad.

2. Replace Defective Ballasts

Ballasts provide starting voltage and regulate current. If HIDs won't start, test and replace the ballast if faulty.

3. Test the Ignitor

Ignitors spark the lamp to initiate discharge. If the lamp won't strike, test the ignitor and replace if not functional.

4. Clean Fixture Contacts

Corroded or soiled contacts cause high resistance and voltage drop. Clean contacts thoroughly.

5. Check for Loose Wiring

Inspect wires and wire nuts for loosening over time. Re-secure all connections tightly.

6. Replace Burned-Out Bulbs

HID lamps require periodic replacement as electrodes wear out. Check lamp hours and replace per manufacturer recommendations.

Safety Precautions

Properly maintaining your commercial lighting system keeps your building bright, your employees productive, and your energy bills in check. Following basic troubleshooting methods and safety procedures will allow you to efficiently diagnose and repair lighting issues. Consider hiring a qualified electrician for complex lighting repairs or large-scale lighting upgrades. With the right diligence and care, your lighting system will shine for years to come.