How to Troubleshoot Obscure Electrical Issues in Older Commercial Buildings

Introduction

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

• The electrical systems in older buildings tend to use outdated technologies and materials that degrade over time. Fraying insulation, corroded connections, and faulty breakers are common.

Improper Modifications

• Unqualified personnel may have made improper modifications over the years like overloading circuits or using incorrect breakers. This stresses the system over time.

Environmental Factors

• Exposure to moisture, dirt, temperature swings, and vermin can cause corrosion, shorts, and other problems. Lack of maintenance accelerates wear.

Power Surges

• Utility power surges or in-house motor starts can cause unexpected voltage spikes that damage equipment. Old surge protectors may no longer work.

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:

• Check for obvious signs of damage like burnt wiring, leaking connections, vermin infestation, corrosion etc.

• Look for modifications made outside the panel like jumper wires, undersized breakers etc.

• Check breakers for signs of overheating which may indicate overload.

• Inspect labels andwiring diagrams for omitted info or inconsistencies.

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:

Voltage

• Check input and output voltage of panels and large equipment. Voltage should not exceed nameplate rating.

Resistance

• Check resistance across breakers and fuses. A low or zero reading indicates a short.

• Check resistance across load wires. Different readings can indicate loose wiring.

Continuity

• Verify end-to-end continuity through circuits. Any open circuit indicates a broken wire.

• Check continuity through safety systems like ground wires.

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

• Split the circuit into halves and test each one to narrow down the bad section.

• Keep bisecting the problem area until you isolate the specific location.

Check Connections

• Wiggle wires and connectors to see if the problem is intermittent.

• Retest all related splices, junctions and terminals for good contact.

Replace Components

• Systematically swap out suspect breakers, fuses, wiring segments until the problem disappears.

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:

• Hire an experienced commercial electrician to assist and offer expertise.

• Engage an infrared thermography service to scan for hot spots.

• Call the utility to audit power quality and surges coming into the building.

• Contact equipment vendors if you suspect a faulty device.

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:

• Replace obsolete equipment like old breaker panels or fuse boxes.

• Add surge protection, lightning arrestors and power conditioning.

• Reroute problematic sections in compliance with current codes.

• Increase load capacity for circuit sections that are overloaded.

• Improve documentation and labeling for future troubleshooting.

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.