This is a tricky one, but here's a breakdown of potential causes and troubleshooting steps you and the electrician can consider, beyond just checking for amp spikes

Potential Causes of the Popping Noise:
Thermal Expansion/Contraction

This is the most likely culprit, especially with LED fixtures in a parking garage exposed to temperature fluctuations. The metal housing of the fixture expands and contracts at a different rate than the LED components or other internal parts. This can cause small friction pops as the materials shift.

Loose Connections

While the electrician likely tightened connections, it's worth double-checking ALL of them, especially on the neutral and ground wires. Loose connections can heat up and cool down under load, causing expansion/contraction and arcing (which can sound like a pop).

Component Issues within the Fixture (LED Driver, Capacitor)

Less likely, but a failing component inside the fixture could be the cause. Could be arcing, discharge, or internal movement within the component.

Voltage Spikes/Surges (Beyond what an amp probe might catch)

While an amp probe is good, it doesn't necessarily capture transient voltage spikes. These can be very short duration but high voltage, and they can stress components and potentially create noise.

Grounding Issues

Improper or inadequate grounding can create potential differences that discharge suddenly, resulting in a popping sound.

Harmonics

Harmonic distortion in the electrical system can cause issues with LED drivers and other electronic components, sometimes leading to noise.

Compatibility Issues

While less common with reputable brands like Acuity, there's a slight chance there's some incompatibility between the LED driver and the existing electrical system (specifically, with any control systems or dimming systems present, even if the fixtures aren't being dimmed).

Physical Vibration

Is the parking garage near a train line, heavy machinery, or some other source of vibration? The vibration might be causing parts within the fixture to rub together.

Defective Batch of Fixtures

While unlikely for a large brand like Acuity, it's always possible the entire batch of fixtures has a defect.

Troubleshooting Steps


Confirm Thermal Expansion/Contraction



Time of Day Observation

Does the popping occur primarily during specific times of day, correlating with sunrise/sunset and temperature changes?

Temperature Measurement

Take temperature readings of the fixture's surface at different times of day, when the popping is more and less frequent. Look for a correlation.

Careful Inspection

With the power OFF, gently press on different parts of the fixture's housing (lens, end caps, etc.). Can you recreate the noise by hand? This could pinpoint the area of friction.2.

Comprehensive Electrical System Check



Voltage Recording

Use a data-logging voltmeter to record the voltage at the fixtures over a 24-hour period. Look for sags, surges, or voltage variations that could be stressing the drivers. A power quality analyzer is ideal.

Neutral-Ground Voltage

Measure the voltage between the neutral and ground wires at the fixture and at the panel. Excessive voltage can indicate grounding issues.

Ground Impedance

Measure the impedance of the grounding system. High impedance can indicate a poor ground connection.

Harmonic Analysis

Use a power quality analyzer to measure the harmonic content of the current and voltage on each circuit.

Arc Fault Detection

Although difficult to pinpoint, see if there is any indication of arc fault events in the panel serving the circuits.3.

Fixture-Specific Troubleshooting



Isolation

Temporarily disconnect one fixture at a time to see if the popping stops. This can help isolate the problem to a particular fixture or circuit.

Fixture Swap

If isolating doesn't work, swap a known "good" fixture (one that doesn't pop) with a "bad" one (one that does). Does the popping follow the fixture, or does it stay with the original location?

Careful Inspection (Power OFF)

Open the fixture (if possible and safe – follow all safety precautions) and carefully inspect the wiring, connections, and components for any signs of damage, loose connections, or arcing. Look for burnt components on the LED driver.

Component Testing (Advanced)

If the electrician is comfortable and qualified, they can use a multimeter to test individual components on the LED driver (capacitors, resistors, etc.) to look for out-of-spec values. This is generally a last resort.4.

Check Mounting and Environment Verify that the fixture is mounted per the manufacturer's recommendation. If bolted to steel beams, ensure that the correct bolts and hardware are used. Check the area around the fixture for any possible interference or other source of noise. Sometimes, noise can travel and seem like it is coming from a different location.

Communication with Acuity



Detailed Information

Provide Acuity with as much detail as possible: Model numbers of the fixtures Date of installation Wiring configuration (voltage, circuit details) Description of the noise (when it occurs, how loud, etc.) Any troubleshooting steps taken so far.

Photos/Videos

If possible, record a video of the popping noise and send it to Acuity. Photos of the installation might also be helpful.

Request Field Support

Ask Acuity to send a field service technician to investigate.

Important Considerations



Safety First

Always prioritize safety. Ensure the power is OFF before working on any electrical equipment. Use appropriate PPE.

Warranty

Be aware of the warranty terms for the fixtures. Troubleshooting steps might need to be coordinated with Acuity to avoid voiding the warranty.

Documentation

Keep detailed records of all troubleshooting steps taken, measurements recorded, and communications with Acuity.

In summary, start with the simplest and most likely cause (thermal expansion) and then systematically work through the electrical system and fixture-specific issues. Detailed observation, thorough testing, and clear communication with the manufacturer are key to solving this problem. Flag for review