How to Troubleshoot Unusual Electrical Grounding Issues in Commercial Buildings


As an electrician working on commercial buildings, I occasionally come across unusual electrical grounding issues that require some extra troubleshooting. Proper grounding is essential for safety and for equipment to function properly. Faulty or insufficient grounding can lead to shock hazards, equipment damage, and poor power quality. In this article, I will share my experience and tips for troubleshooting unusual grounding problems in commercial settings.

Common Causes of Unusual Grounding Issues

There are a few key factors that can lead to atypical grounding situations:

Older Electrical Systems

Many older buildings have outdated electrical systems that were installed before current grounding codes and standards were in place. Often, the grounding measures are inadequate or have degraded over time.

Incompatible Mix of Electrical Systems

It's common for commercial spaces to have an incompatible mixture of old and new electrical systems cobbled together over time as upgrades are made. This mismatch can create grounding discontinuities.

Use of Improper Grounding Procedures

In some cases, previous electricians may have used improper grounding methods against code requirements, leading to problems down the road.

Faulty Main Bonding Jumper

Issues with the main bonding jumper between the neutral and ground at the main service panel can lead to voltage on the grounding system throughout a building.

Corroded Grounding Electrodes

Over time, ground rods, water pipes, or concrete encased electrodes can become heavily corroded, damaging their effectiveness as grounding electrodes.

Signs of Abnormal Grounding Issues

Some of the typical indicators that unusual grounding problems may be present include:

If I come across any of these symptoms, it prompts me to do further testing to isolate the root cause.

Steps for Diagnosing Problems

When troubleshooting tricky grounding issues in commercial buildings, I take a systematic approach:

Inspect and Verify Main Grounding Electrode System

Test for Voltage Between Neutral and Ground

Evaluate Grounding Electrode Resistance

Check for Shared Neutral Issues

Inspect Equipotential Bonding

Consider Stray Currents

By methodically working through these test procedures, I can usually get to the bottom of atypical grounding issues.

Solutions for Faulty Grounding

Once I've identified the cause of abnormal grounding, there are several ways I can restore proper functioning:

In many cases, upgrading to a modern grounding system per NEC and IEEE guidelines is the best long-term solution.

Key Takeaways

Troubleshooting unusual grounding issues in commercial buildings requires patience and a systematic approach, but can be solved with persistence. The keys I've learned are:

No two grounding problems are exactly alike, but with the right knowledge and methodical troubleshooting, even tricky grounding issues can be solved for safe and robust electrical systems. Let me know if you have any other questions!