Electrical Codes for Grounding

Electrician Training Electrical Certification wiring recessed light fixtures Electrical Wiring Electrical Troubleshooting and Electrical Repairs wire outdoor light fixture Home Electrical Wiring Diagrams
wiring home generator and transfer switch wiring a 220 volt range cord outlet Wiring for GFCI Outlets Wiring Outlets and a Switched Outlet Wiring and Installing Ceiling Fans and Remote Controls wire dimmer switch wiring diagrams for switches wiring a dryer cord and 220 outlet circuit breaker panel
Electrical Wire and Cable

Electrical Codes for Grounding

home-electrical-codes-for-grounding By
Summary: Listing of electrical codes for grounding with examples of electrical grounding codes for home electrical wiring.

Electrical Code Definitions for Grounding Home Electrical Systems

Understanding the Importance of Electrical Grounding

NEC 250.5
Grounding and Bonding

Grounding and Bonding All grounding electrodes that are present at each building or structure served shall be bonded together to form the grounding electrode system.

Code Adoption Information: The codes shown are examples only and may not be current or accurate for your application or jurisdiction. Contact your local building authority for complete information.


NEC 250.5 Grounding and Bonding
Grounding and Bonding Electrodes include a metal underground water pipe in direct contact with earth for 10 feet or more, a metal frame of a building or structure, a concrete encased electrode or a ground ring

NEC 250.28 Grounding and Bonding Grounding and Bonding
A main bonding jumper or the green bonding screw provided by the panel manufacturer shall be installed in the service panel.

NEC 250.32 Grounding and Bonding
Grounding and Bonding Buildings supplied by a branch circuit or feeder shall have an equipment grounding conductor run with the supply conductors and connected to the grounding electrode system at the separate building.

NEC 250-50 A premise's electrical service shall be connected to a grounding electrode system consisting of a metal underground water pipe in direct contact with earth for 10 feet or more, if available on the premises, and a supplemental electrode (a rod, pipe, or plate electrode.) An additional electrode shall supplement the buried water pipe electrode.

NEC 250.53 Grounding and Bonding Grounding and Bonding
A metal underground water pipe shall be supplemented by an additional electrode, such as an approved rod, pipe or plate electrode.

NEC 250.64 Grounding and Bonding Grounding and Bonding
The grounding electrode conductor shall be continuous, securely fastened and protected from physical damage.

NEC 250.66 Grounding and Bonding Grounding and Bonding
The size of the grounding electrode conductor shall be determined by the size of the service-entrance conductors, per the following chart:

Equivalent Size of Service Entrance Conductor Size
of the Grounding Electrode Conductor

Copper - - - Aluminum - - - Copper Aluminum
..4 AWG... ... ..2............ ........8*........6
..1 AWG..... ...2/0............. . ...6.........4
..2/0 or 3/0.... .4/0 or 250.......4.........2
*The conductor that is the sole connection to a rod, pipe or plate electrode is not required to be larger than #6 AWG copper, however smaller conductors require physical protection.

NEC 250.104 Grounding and Bonding Grounding and Bonding
The interior metal water piping and other metal piping that may become energized shall be bonded to the service equipment with a bonding jumper sized the same as the grounding electrode conductor.

NEC 250.134 Wiring Methods Grounding
All electrical equipment, metal boxes, cover plates, and plaster rings shall be grounded. All switches, including dimmer switches, shall be grounded.

NEC 408.41 Wiring Methods Grounded Conductor
Each grounded conductor shall terminate within a panel board in an individual terminal that is not used for any other conductor.

NEC Code Index

NEC Article Index for Section 250

Grounding and Bonding

Listing of NEC Articles which cover the subject of Grounding and Bonding


Bonding Conductors and Jumpers 250.102
Bonding for Other Systems 250.94
Bonding for Over 250 Volts 250.97
Bonding of Piping Systems and Exposed Structural Steel 250.104
Bonding Other Enclosures 250.96

General 250.90
Lightning Protection Systems 250.106
Services 250.92

Direct-Current Systems

Size of the Direct-Current Grounding Electrode Conductor 250.166

Equipment Grounding and Equipment

Grounding Conductors
Equipment Connected by Cord and Plug 250.114
Equipment Fastened in Place (Fixed) or Connected by Permanent Wiring Methods 250.110
Equipment Grounding Conductor Installation 250.120

Identification of Equipment Grounding Conductors 250.119
Identification of Wiring Device Terminals 250.126
Size of Equipment Grounding Conductors 250.122
Specific Equipment Fastened in Place (Fixed) or Connected by Permanent Wiring Methods 250.112
Types of Equipment Grounding Conductors 250.118
Use of Equipment Grounding Conductors 250.121


Clean Surfaces 250.12
Connection of Grounding and Bonding Equipment 250.8
Definitions 250.2
General Requirements for Grounding and Bonding 250.4
Objectionable Current 250.6
Protection of Ground Clamps and Fittings 250.10 Scope 250.1

Grounding Electrode System and Grounding Electrode

Auxiliary Grounding Electrodes 250.54
Common Grounding Electrode 250.58
Grounding Electrode Conductor and Bonding
Jumper Connection to Grounding Electrodes 250.68
Grounding Electrode Conductor Installation 250.64
Grounding Electrode Conductor Material 250.62
Grounding Electrodes 250.52
Grounding Electrode System 250.50
Grounding Electrode System Installation 250.53
Methods of Grounding and Bonding Conductor Connection to Electrodes 250.70
Size of Alternating-Current Grounding Electrode Conductor 250.66
Use of Strike Termination Devices 250.60

Enclosure, Raceway, and Service Cable Connections

Other Conductor Enclosures and Raceways 250.86
Service Raceways and Enclosures 250.80

Methods of Equipment Grounding

Connecting Receptacle Grounding Terminal to Box 250.146
Continuity and Attachment of Equipment
Grounding Conductors to Boxes 250.148
Cord-and-Plug-Connected Equipment 250.138
Equipment Considered Grounded 250.136
Equipment Fastened in Place or Connected by Permanent Wiring Methods (Fixed) Grounding 250.134
Equipment Grounding Conductor Connections 250.130
Frames of Ranges and Clothes Dryers 250.140
Use of Grounded Circuit Conductor for Grounding Equipment 250.142

System Grounding

Alternating-Current Systems of 50 Volts to Less
Than 1000 Volts Not Required to be Grounded 250.21
Alternating-Current Systems to be Grounded 250.20
Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s) 250.32
Grounding Separately Derived Alternating-Current Systems 250.30
Grounding Service-Supplied Alternating-Current Systems 250.24
High-Impedance Grounded Neutral Systems 250.36
Main Bonding Jumper and System Bonding Jumper 250.28
Permanently Installed Generators 250.35
Portable and Vehicle-Mounted Generators 250.34

Residential Electrical Code Examples for Grounding

IRC Codes


1.A grounding electrode system shall bond to one of the following items if they are available 2003 IRC E3508.1:
a. Metal underground water pipe, unless it is further than five feet from the building b. Concrete encased electrode/footing rebar c. Grounding rod/ring

2. Continuity of the grounding path to interior piping shall not rely on water meters, filters, or similar equipment. 2003 IRC E3508.1.1

3.Interior metal water piping shall be bonded to the service equipment enclosure or the grounded conductor at the service or the grounding electrode when of sufficient size. 2003 IRC E3508.1.1

4.Grounding clamps must be listed for the materials of the grounding electrode and for direct soil burial. 2003 IRC E3511.4

Always contact your local building authority for complete and up to date code information.

More about Electrical Codes for Grounding


Frequently Asked Questions

Questions about Residential Electrical Wiring Codes for EGS Grounding and Bonding

Question from Joseph, a Handyman in Mesquite, Texas.

My question is concerning my breaker box.

Are ground wires allowed on the same buss bar as neutrals wires? Is this a safety concern in a 1981 home build? I have never had any issues so far.

Dave’s Answer:

Joseph, Ground wires are allowed on the same buss bar as the neutral wires at the main panel where the main ground wire is located and bonded. If the panel is a sub panel, or any other panel other than the main panel, then the neutral buss and the ground buss must be separated and have separate wires to each of them.


Join the Discussion!

Add Your Electrical Question or Comment

Electrical Code Question
click here to ask a electrical code question
click here to leave a comment

»Avoid Costly Mistakes«
Wire It Right with the help of my Illustrated Wiring Book

Great for any Home Wiring Project,
Perfect for the Homeowner, Handyman, Electrician and Building Inspector.
Learn more about Residential Electrical Wiring Codes
Complete Guide to Home Electrical Wiring
Perfect for Homeowners, Students and Electricians
Fully Illustrated
Home Electrical Wiring - Room by Room
Wiring 120 and 240 Volt Circuits
Wiring Main Panels
Underground and Overhead Services
Grounding and Bonding
55 Electrical Code Topics
6 Most Commonly Used Code Tables
11 Home Wiring Plans
Over 370 Photos
28 Wiring Diagrams and Illustrations
Illustrated Wiring Methods
Wiring Codes for Home Electrical Wiring
....and much more.

» Click here to learn more about Home Electrical Wiring «
  electrical wiring  

Search to see more.....

Questions and answers about NEC National Electrical Codes, NFPA Codes for Home Electric Wiring Projects, Electrical Grounding and Bonding, Main Electrical Panels and Sub Panels, Codes for Electrical Wire Size, new and upgrade electric wiring.

Your question may already be answered,
use this search to see answers:

Do you have an Electrical Question?
Ask an Electrical Question

Top of Page