Grounding to Water Pipes- Electrical Inspections

By
Home Inspector with NCW Home Inspections, LLC

Grounding to Water Pipes- Electrical Inspections- Wenatchee and Quincy Home Inspections

When performing a home inspection and evaluating the electrical system I am always trying to confirm if a grounding system is proper.

The Washington State Home Inspector Standards of Practice states (WAC 308-408C-110 Electrical system.)-
A home Inspector must:
(b) Report (i) The existence of a connected service-grounding conductor and service-grounding electrode when same can be determined.  (ii) When no connection to a service grounding electrode can be confirmed.

The purpose of the grounding electrode is to be connected to earth and to the electrical equipment so it establishes a zero difference of potential between the earth and the electrical equipment. This zero difference of potential helps stabilize voltage for the electrical system.

In addition the grounding electrode system is used to limit the voltage imposed on the electrical system by lightning, line surges, or unintentional contact with higher-voltage lines.

Now during a home inspection it may not be easy to locate and I may not find it. Grounding electrodes can be buried and often not visible.


In many older homes it is common to use the water pipe as the primary grounding electrode. But often not within 5 feet of the entrance of the home.

                           Proper Grounding using water pipe -Wenatchee Home Inspection

The National Electrical Code states (per 2005/2008 NEC)-
250.52 Grounding Electrodes.   (A) Electrodes Permitted for Grounding.  
(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.

There is a good reason for the 5 foot rule. Often in these older homes the plumbing has been modified and replaced with materials that are not conductive such as plastics. Also you want to make sure that if you have a removable component such as a pressure reducing valve or meter etc… that you do not lose ground during replacement or servicing.

Here we have a perfect example of why this rule is so important. On this home inspection I found the ground has been severed when re-piping was performed. This home is now without a ground and is a safety issue.

                               Grounding lost from re-piping Quincy Home Inpections

Being “Grounded” is always a good thing.



“A shocking occurrence ceases to be shocking when it occurs daily. “

Alexander Chase


NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…


Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service



www.ncwhomeinspections.com          509-670-9572


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Topic:
ActiveRain Community
Location:
Washington Grant County Quincy
Groups:
Ask the Home Inspector
Adventures in Home Inspecting
Active Rain Newbies
Tags:
quincy home inspection
wenatchee home inspection
electrical inspections
grounding to water pipes

Comments 28 New Comment

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Rainmaker
341,693
Donald Hester
NCW Home Inspections, LLC
NCW Home Inspections, LLC

John, Thank you.

Jon, On most of from the 60/70's forward will have ground rods.

October 27, 2012 08:16 AM
Rainer
83,887
Brad Baylor
ERA Coup Agency

Donald - As you mentioned, the main issue I see with proper grounding is when the plumbing has been replaced, or partially replaced with pex or some other non-conductive material.

October 30, 2012 07:01 AM
Rainmaker
341,693
Donald Hester
NCW Home Inspections, LLC
NCW Home Inspections, LLC

Brad, This becomes pretty common when you are re-piping older homes.

October 30, 2012 07:28 AM
Rainmaker
260,268
Wayne B. Pruner
Tigard Oregon Homes for Sale, Realtor, GRI
Oregon First

It was an accepted practice to just ground to the water pipes. Now, with good reason, grounding rods are required. Any updating requires a rod to be installed.

November 27, 2012 08:38 PM
Rainmaker
341,693
Donald Hester
NCW Home Inspections, LLC
NCW Home Inspections, LLC

Wayne, It is a good idea to even supplement water pipes with ground rods. Can not have enough good grounding.

November 27, 2012 08:42 PM
Anonymous
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Rainmaker
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Donald Hester

NCW Home Inspections, LLC
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