Old Electrical Wiring: Evaluating, Repairing, and Upgrading Dated Systems

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Old Electrical Wiring: Evaluating, Repairing, and Upgrading Dated Systems

Old Electrical Wiring: Evaluating, Repairing, and Upgrading Dated Systems

Authors: David Shapiro

Published: July 2010

eISBN: 9780071663564 0071663568 | ISBN: 9780071663571

Cover

About the Author

Title Page

Copyright Page

Contents

Foreword

Foreword to First Edition

Acknowledgments

Additional Acknowledgments for the Second Edition

Chapter 1: Introduction

Overview

Chapter 2: Hazards and Benefits

Dangers of Old Wiring

Special Risks in Old Work

Problems Added by Older Wiring

Other Dangers of Work on Older Structures

Resources

Rational Response to These Concerns

The Benefits of Learning about Old Wiring

Closing Reflection

Chapter 3: Troubleshooting

Overview

A Heads-Up on Safety

Using All Available Evidence

Sizing Up the Problem

General Rules

Fatigue Often Is the Villain

Lighting Outlets Are Frequently Trouble Spots

My Common Order of Approach

The Effects of Deterioration

Energized Testing Procedures

Playing It Safe(r) as I Pull Things Apart

Proceeding to Explore

Proceeding Inside an Old Outlet Box

Troubleshooting Old Splices

Evaluating Bad Wires

Healing Old Wires

Receptacle Troubleshooting and Replacement

Bonding Equipment on Which I Have Worked

Grounding Problems

Chapter 4: Modified Designs and Changed Practices

Mysteries

Puzzling Switches

Some Simple Possibilities

Some Messier Possibilities

Problems Created by Ignorance About Boxes and Wires

Ways That I Add Room to Enclosures

Grandfathering Issues

Backstabbed Devices

Closet Lights

Solutions to the Problem of Closet Lighting

Grandfathering: The Bigger Picture

My Responsibility with Regard to What Already Exists

An Esoteric Switching Layout: The Carter System

Chapter 5: An Esoteric Switching Layout

The Logic of the Design—What Makes the Lights Light

Multipoint Switching and the Carter System

Comparing Carter Designs With Standard Multipoint Switching

More Complicated Carter System Designs

Recognizing Carter System Switching

Looking Inside the Switch Boxes

Relevant History

Troubleshooting at the Switched Outlet

A Rough Parallel to Carter System Wiring

What Carter System Switching Accomplished

A Closer Look at the Carter System’s Drawbacks

Polarity Loss

Induced Current

Responding to the Carter System

Even If It Is Broke, Must I Fix It?

Fix-It Options

Elimination

Rewiring

Troubleshooting

Chapter 6: Unusual and Odd Equipment and Designs

Loadcenters in Unexpected Locations

How I Deal with Oddly Located Overcurrent Devices

Outdated Circuit Breakers

Classified Information

Complex Kludges I’ve Encountered

Polarity Gone Amuck

Downstream Grounds: Returns to Haunt

Ranges and Dryers

Antiques

Merely Odd and Antique

Crowfoots

Sheer Ignorance

Three More Hazards

Buried Splices

Knob and Tube (Initially Discussed in Chapter 3)

Illegally Buried Splices

Unexpected Power

My Response to Finding Power Present When It Should Be Absent

Unlisted Equipment

Indoor Meters

Aluminum

Heavier Cables

Aluminum Branch Circuit Wiring

It’s Not Al All the Time

And It’s Not Always Copper!

Repairs

Making Connections Involving Aluminum Branch Circuit Wiring

Relay Switching

Thermostats

Telephones

Miscellaneous Rarities

Old Breakers

Odd Fuses and Fuseboxes

Old Fuse Types

Combination Panels

Energized-Front Fuseboxes

Asbestos

Switched Plug Fuses

When the New Is Hazarded by the Old

Chapter 7: Commercial, Industrial, and Institutional Wiring

Special Service and Tweaking Power

Not Quite the Right Voltage

Phase and Frequency Differences

Addressing an Awkward Class of Service

Upgrading Class of Service

“Plain” Old Motor Replacement

Exotic Motors

Matching the Power to the Load

Leaving It Functioning and Safe

Lighting Upgrades

Exit Signs

Fluorescent Fixture Inserts

CFLs

Easy Improvements in Lighting Efficiency

When System Age Needs to Be Considered in Pursuing Efficiency

Other Risks Associated with Old, Nonresidential Buildings

Easy Ways to Upgrade Low-Voltage Systems

Assorted Errors

Overly Isolated Grounding

Bad Reactions to Noise

Ill-Considered Reactions to Pinholing

Too Much Tightening

Thoughtless Risk-Taking by Customers

Risks Created in Commercial Occupancies by Careless Electricians

Multiwire Misapplications

Breaker Misapplication

Anonymous Installers: Trouble They Create

Changing Rules: Neon

It’s Been Worth Taking the Trouble to Find Out What the Customer Wants—and Needs

Anticipating Change

Chapter 8: Accept, Adapt, or Uproot?

Paddle Fans and Other Upgrades

Boxes

Crowded Boxes

Box Replacement: Additional Benefits

Less-Than-Ideal Locations

Old Boxes and Their Accessories

Mating Fixtures to Boxes and Protecting Combustibles

New Fixtures Meet Old Wiring

Old Does Not Mean Bad

Some Outdated Designs Do Have to Go

Superannuated Devices

Despard Devices

Mercury Switches

Antique Dimmers

Rebuildables

Rosettes

Suboptimal Designs

Grounding and Bonding

Iffy Wiring Methods

The Isolation Option

Efficiency Improvements

Chapter 9: Tearing Out Old Wiring and Rewiring Older Buildings

When Is Rewiring Critical?

Options for Rewiring

Mimicking New Construction: The Gut or Semigut Job

Cooperation and Coordination with Other Trades

Lucky Breaks: When the Existing System Makes My Job Easy

Toughing It Out—More Difficult Approaches

Example: Going Fishing

Further Choices

Leaving the Existing Wiring in Place

Unobtrusive Cables

Chopping or Disassembling

Paneling Can Offer a Less Obtrusive Option

In and Out

Exposed Interior Work

Surface Cables and Raceways

Chapter 10: Inspection Issues

Inspection Counts!

Judgment Calls

Neat and Workmanlike

Example

Reasonable Accommodation

Filling the Holes in NEC’s Coverage

When Am I Required to Pull a Permit?

Can the Installation Be Grandfathered?

When Is It Reasonable to Reconnect Old Equipment?

After-the-Fact Inspection

Chapter 11: Grandfathering, Dating, and Historic Buildings

Grandfathering

Dating

Fickle Dates

Piecemeal Compliance

Historic Buildings

Special Rulebooks

Urgent Needs

Old, Odd, and Unsafe Equipment

Gas to Electric

Satisfying Aesthetic Requirements

Service Changes

Appendix: Jargon and Abbreviations

Index