How to Troubleshoot Uncommon 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. However, with some knowledge of common problems, a methodical approach, and the right tools, many uncommon electrical issues can be effectively diagnosed and repaired. In this article, I will provide an in-depth guide on how to troubleshoot a range of unusual electrical problems in vintage commercial structures.

Understanding the Electrical System

Older commercial buildings often have antiquated electrical systems that may include:

• Fuse boxes - Predates circuit breaker panels. More prone to failure.

• Aluminum wiring - Problematic if connections become loose.

• Knob and tube wiring - Outdated, can fail over time.

• Outdated breaker panels - May lack capacity for additions.

• Complex wiring - Numerous alterations over the years.

• Mixed wiring types - Different install eras with inconsistent wiring.

• Lack of documentation - Original plans may be unavailable.

It is critical to learn as much as possible about the existing electrical system before troubleshooting issues. Review any available documentation, inspect the main service panel and subpanels, and trace circuits to understand the wiring layout. Being familiar with the system makes finding problems easier.

Common Unusual Electrical Issues in Old Buildings

Some uncommon electrical issues found in old commercial spaces include:

• Intermittent power losses - Loose connections, outdated wiring.

• Flickering lights - Faulty neon sign transformers, loose connections.

• Circuit overload tripping - Outdated wires, increased load.

• GFCI or AFCI breaker tripping - Ground faults, arcing faults.

• Uneven lighting - Voltage drop from long circuit runs.

• Unexplained fuse blowing - Overload, short circuit.

• Electrical burning smell - Overheating wires, bad connections.

• Tingling feeling - Ground fault.

Many uncommon issues arise from the aging electrical system components and outdated installation methods. Being aware of the range of possible unusual problems will make troubleshooting more targeted.

Troubleshooting Process and Methods

A systematic troubleshooting approach is essential for diagnosing odd electrical gremlins. Here are key troubleshooting steps:

Inspect and Ask Questions

• Inspect area thoroughly, look for signs of problems.

• Interview occupants about when issue occurs.

• Review maintenance history for clues.

• Determine all changes/additions recently made.

Consider Likely Causes

• Based on symptoms and unit age, make a list of probable causes.

• If multiple issues occur together, they may share a cause.

Test and Measure

• Use DMM to measure voltage drops, resistances.

• Check connections for loose wiring or poor contacts.

• Verify circuits are properly grounded.

• Test GFCIs and AFCIs with button tests.

• Isolate sections of circuitry to narrow down faults.

Safety First

• Use PPE - glasses, gloves, wear insulation.

• Only work on de-energized circuits!

• Use properly rated test equipment.

Work methodically to isolate the issue while verifying your safety.

Tips for Specific Unusual Electrical Problems

Intermittent Power Loss

• Check connections in entire circuit path for corrosion or looseness.

• Lightly shake wires/cables while powered - any change indicates loose wiring.

• Look for signs of overheating - discolored wires, melted insulation.

Flickering Lights

• Check bulb integrity and fixture connections.

• For neon signs, listen for humming/crackling from transformers.

Tripping Breakers

• Verify breaker size - if undersized, replace with higher amp version after verifying wire gauge.

• For overload tripping, rearrange circuit loads to reduce power.

• For AFCI/GFCI nuisance tripping, replace sensing module.

Uneven Lighting

• Measure voltage drops at farthest fixture vs. panel to check for excessive line loss.

Unexplained Fuse Blowing

• Check for short circuits between conductors or to ground with insulation tester megger.

• Look for signs of overheating - an overload causes excessive heat.

When to Call an Electrician

For hazardous situations, complex issues, or working in the main panel, contact a qualified electrician:

• Main service upgrade.

• Replacing deteriorated wiring.

• Tracing complex wiring faults.

• Diagnosing tripping main breaker or blown main fuses.

Safety should be the top priority - know your limits.

Conclusion

Troubleshooting odd electrical gremlins in vintage commercial buildings requires knowledge of antiquated systems, potential uncommon issues, and methodical diagnostic techniques. Focus on safety, isolate problems through testing, and don't hesitate to call a professional electrician when needed. With diligence and care, even uncommon electrical issues can be effectively resolved.