How to Troubleshoot Obscure Electrical Issues in Older Commercial Buildings


Troubleshooting electrical issues in older commercial buildings can be challenging due to the age and complexity of the electrical systems. As a technician, I often encounter obscure problems that require some detective work to resolve. In this article, I will provide an in-depth guide on how to systematically troubleshoot even the most obscure electrical gremlins in these aging electrical systems.

Common Causes of Electrical Issues

Before jumping into testing and troubleshooting, it's important to understand the most common root causes of electrical issues in old commercial buildings:

Aging Infrastructure

Improper Modifications

Environmental Factors

Power Surges

Safety First

Before any troubleshooting, confirm the power is off and locked out. Use PPE like insulated gloves and mats. Many older systems use live parts that can electrocute. Assume all circuits are live until tested.

Visual Inspection

Start troubleshooting by thoroughly inspecting the electrical system:

Often, the visual inspection alone will reveal the issue. If not, more testing is required.

Testing the Basics

With power isolated, use a multimeter to methodically step through testing:




Document all voltage drops, abnormal resistance or continuity findings for further diagnosis.

Isolating the Problem

Now comes the real detective work to isolate where the actual fault lies:

Divide and Conquer

Check Connections

Replace Components

Patience is key here, along with meticulous documentation of each step tried.

Seeking External Expertise

For the most obscure issues, don't hesitate to seek help:

A fresh set of eyes can sometimes spot what you've overlooked.

Restoring and Improving the System

Once the specific problem is found, address the direct fault but also look for opportunities to improve the overall system:

With some diligence and testing discipline, even obscure electrical gremlins can be defeated. Use a systematic approach, enlist help when needed, and take the opportunity to improve the overall system. Safe and reliable power will return to the facility.