How to Troubleshoot Tricky Electrical Faults in Commercial Buildings

Diagnosing and resolving electrical faults in commercial buildings can be challenging. As an electrician, you may encounter complex wiring configurations, unfamiliar equipment, and elusive intermittent issues. However, with the right approach and diagnostic tools, even the trickiest electrical gremlins can be tracked down and fixed.

Understanding Common Causes of Electrical Issues

Before attempting to troubleshoot, it helps to understand the most frequent causes of electrical faults in commercial settings:


Drawing too much current through an undersized circuit or electrical component can lead to overheating and failure. Overloads often result from:

Symptoms: Breakers tripping, burning smells, hot outlets/cords, equipment shutdowns

Loose Connections

Loose wiring connections can lead to arcing, intermittent contacts, and component failures. Causes include:

Symptoms: Flickering lights, power fluctuations, partial outages

Ground Faults

Ground faults happen when electricity escapes its normal path and flows through the grounding system. Triggers can include:

Symptoms: GFCI or AFCI breakers tripping, tingling sensations from metal surfaces

Switching Transients

Switching large inductive loads like motors, compressors, and transformers can produce voltage spikes or transients. Effects include:

Symptoms: Equipment failures during startup/shutdown, unexplained breaker trips

Gathering Background Information

To get a head start on diagnosing issues, gather as much background information upfront as possible:

Document all findings to help narrow down culprits before testing begins.

Using Diagnostic Tools and Methods

With a general idea of the nature of the problem, use these diagnostic tools and methods to pinpoint the exact fault:

Clamp Meter

A clamp meter allows current measurements without breaking the circuit. Use it to:

Voltage Tester

A voltage tester quickly detects live power. Use it to:


A megohmmeter is used to measure insulation resistance. Use it to:

Circuit Tracers

Circuit tracers inject a signal and use a detector wand to identify connected wires. Use them to:

Thermal Camera

A thermal camera makes hot spots and connections visible. Use it to:

Electrical Testers

Advanced electrical testers can monitor power quality, harmonics, and transients. Use them to:

Isolating the Fault

Once measurements and tests identify the kind of fault, isolate the location through systematic elimination:

Checking the components closest to the source first will usually get you to the fault faster.

Addressing Common Fault Conditions

With the problem narrowed down, apply the following fixes for common fault conditions:


Loose Connections

Ground Faults

Switching Transients

Following proper troubleshooting procedures and addressing the root causes of electrical issues will lead to long-lasting reliable operation of commercial electrical systems.