rkenney Posted May 30, 2011 Report Share Posted May 30, 2011 Hi group, this is my first post so please bear with me. I just got Rex Cauldwell's book "Inspecting a House" for 2.99 off E-bay. Some great illustrations for a newbie who hasn't seen much (me). My question is this, he says (on pge. 43 if you have the book) that there needs to be a ground rod from the service panel even if the metal plumbing is grounded (bonded). This is the only place I've read this. All the houses I've done, including my own, only have one or the other. Ground rod if you have plastic (PB) water main and vice versa. What is the correct (new code -old code ?) situation here? Should I report service entrance panels without both? I'm licensed for Maryland if region makes any difference. www.IndependentHomeInspectionMD.com Quote Link to comment Share on other sites More sharing options...
Richard Moore Posted May 31, 2011 Report Share Posted May 31, 2011 250.53(D) Metal Underground Water Pipe. Where used as agrounding electrode, metal underground water pipe shall meet the requirements of 250.53(D)(1) and (D)(2). (1) Continuity. Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment. (2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(7). Where the supplemental electrode is a rod, pipe, or plate type, it shall comply with 250.56. The supplemental electrode shall be permitted to be bonded to the grounding electrode conductor, the grounded service-entrance conductor, the nonflexible grounded service raceway, or any grounded service enclosure. So...in a modern set-up if they are using buried metallic water pipe as the main electrode, you should also see a supplemental (typically ground rod(s)). But in a house with a plastic water service you would normally see just the one type of electrode (rods or UFERs). Many older houses around here will only have the supplemental ground rods if the panel or service has been upgraded in the last couple of decades (or so). Someone else may know when the supplemental requirement actually came into being. Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted May 31, 2011 Report Share Posted May 31, 2011 . . . Someone else may know when the supplemental requirement actually came into being. Richard, The requirement for a supplemental electrode came into being with the 1984 NEC. Back then, it was at 250.81(a). (Oops, correction, Douglas pointed out that it was actually the 1978 edition.) Bob, Welcome to TIJ. Just because the NEC has required a supplemental electrode for the last 33 years does not mean that Maryland does. States can be slow to adopt new editions of the model codes and when they do, they can make changes to them. We have some folks from Maryland on this forum, they might know about the specific rules there. I've also got to point out that, while Cauldwell is correct about this issue, I think you overpaid for the book. I remember looking through it when it came out. I chose three pages at random and found errors on each of the three pages. Verify everything in there before accepting it as true. Quote Link to comment Share on other sites More sharing options...
rkenney Posted May 31, 2011 Author Report Share Posted May 31, 2011 Thanks Jim and Richard for the replies. I am a firm advocate of "measure twice and cut once," and this applies to words as well (my wife may disagree . So I appreciate the clarification you've provided. It was worth the $2.99 simply to raise and answer the question. I am always ready to learn although I do not always like being taught. Winston Churchill Bob Kenney, Maryland www.IndependentHomeInspectionMD.com Quote Link to comment Share on other sites More sharing options...
Jim Port Posted May 31, 2011 Report Share Posted May 31, 2011 Baltimore County has required the rods in addition to the metallic water line for a long time. New construction would require a Ufer ground. Quote Link to comment Share on other sites More sharing options...
John Dirks Jr Posted June 28, 2011 Report Share Posted June 28, 2011 When I need to find area specific code and to find out what version are currently in force, I usually Google the specific county. Example: google search "anne arundel county electrical code" Find: http://www.aacounty.org/IP/PAC/BuildingCodes.cfm The page shows what versions of various code apply to the various categories. This particular page for Anne Arundel County has a link to amendments in Bill 46-03 at the top of the page. It requires some scrolling but additional information can be found there. Other counties have similar information available online. Quote Link to comment Share on other sites More sharing options...
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