George, thanks for the response. TO clarify on the water heater being gas or electric.
I contacted a local electrician and his response about weather a bond was needed around the section of PEX (in the home distribution, not to the service) was if there is an electric water heater element that shorts out, it can cause shock in the water line. If its gas, it has no electricity so no need to connect both sides of the copper around the pex addition of pipe.
I have currently found in some of INTERNACHI training materials:
“A jumper or bonding conductor is a conductor used to ensure that there is electrical conductivity between metal parts that are required to be electrically connected. For example, a jumper may be installed over the water meter because the continuity of the grounding path or bonding connection of the interior pipes should not rely on the water meter. The jumper is a large-gauge conductor that “jumps” over the water meter and is securely attached to the metal water pipe on each side.”
To take the this further, I have read that metal plumbing likely to be energized need to be bonded to grounding.
The question is if there is a break in the metal distribution plumbing throughout the home (not just the supply from the municipality) is a bond needed to jump from the side that is currently bonded to the panel grounding, required to be bonded to the other side of the newly installed pex line to the far section of metal plumbing?
Yes, this gets to the answer, thank you. Generally, if there is a water bond (having the assumed 10’ of earth contact) it is combined with a ground rod (1 only). I recommend they upgrade to the current standards of 2 ground rods…
As for the potential of having a replacement of a metallic water line with 10’ of ground contact (an earlier response), requiring 2 ground rods to be added, I do not recommend anything but upgrading to the current standard of 2 ground rods based on there only being one. I have never read anywhere that refers to the potential of a water line replacement to non metallic requiring 2 ground rods. Obviously, if the water line is converted to a non metallic pipe, the proper grounding would be required. But I guess one could say any metallic water line will likely fail in the future and then need replacement, therefore requiring 2 ground rods. So either are okay I guess. The issue is with the current market being slow, realtors want to sell the one house they have, not work to find another. Referring to the possibility of such a cost can scare away buyers, therefore hurting the relationship with realtor for the inspector. This is always a constant balance and each inspector needs to determine the extent of what they suggest for the future repairs or requirements.
I do not consider the realtor in my decision making concerning defects. Truthfully, I know we all have to survive, but satisfying realtors is guaranteed diminished return.
This is from the 2011 National Electrical Code Handbook. Although not code it is commentary on why certain things exist in the NEC. Also if a single rod electrode is 25Ω or less only one is required so without testing a single rod how would one know whether or not it meets the 25Ω threshold?
Section 250.53(D)(2) specifically requires that rod, pipe, or plate electrodes used to supplement metal water piping be installed in accordance with 250.53(A). This requirement clarifies that the supplemental electrode system must be installed as if it were the sole grounding electrode for the system. As specified in the exception to 250.53(A)(2), if a single rod, pipe, or plate electrode has a resistance to earth of 25 ohms or less, it is not necessary to supplement that electrode with one of the types from 250.52(A)(2) through (A)(8). In other words, a single rod, pipe, or plate electrode being used to supplement a metal underground water pipe type electrode is itself required to be provided with a supplemental electrode unless the condition of 250.53(A)(2) Exception can be met. One of the permitted methods of bonding a supplemental grounding electrode conductor to the grounding electrode system is to connect it to the grounded service enclosure. The requirement to supplement the metal water pipe is based on the practice of using a plastic pipe for replacement when the original metal water pipe fails. This type of replacement leaves the system without a grounding electrode unless a supplemental electrode is provided.
Amen! We have one particular realtor we will no longer work with. Her expectation seems to be we should be soft on major defects even if they are life-threatening. Sorry sweetheart, your business is not worth our risk.
Don’t get me wrong, I am all about pointing out a defect AND putting it into context. I am just referring to the fact that around here (small area), you will not last long if you don’t play nice with the people in the game. Realtors are the biggest obstacle for me when trying to explain a defect to a client. But also putting the defect into the context of it being a safety item, a wear item or a simple repair, is another. It would be great if everyone could just get along. But some done play well with others. I agree, those agents have to go.
That is interesting. Insecure agent or agent trying to control the narrative. Sad. I try not to correct agents or even give them much room to talk to be honest (unless they are agreeing with me )
I did learn this trick. During a walk-thru type summary with an agent present…move quickly. Point out the “Bigs” and just say simple things like, “I recommend you get that fixed (our southern term for repaired)”. Then, let the report speak for itself. Reminding the client the walk-thru is not everything that will be in the report, be sure to read it all.
They must accept that they do in my area. They being the local power company and all of the local code authorities. I say that because I don’t remember ever seeing a home with more than one ground rod.
It’s certainly possible that soil conditions in your area would consistently get the single rod to 25Ω or less so they don’t require a second rod. The NEC would require the single rod to be tested to prove the 25Ω or less.
Totally agree. For example, missing TPRV tube $15 in parts and glue if your handy. Add about $85 for plumber if not. Bad GFCI, $19.95 at Home Depot and maybe $100 for electrician.
The one agent I reference would argue the TPRV shouldn’t even be in the report and we are causing her undue work and stress.
As mentioned, go find another inspector. We have plenty of agents who understand we are not going to have it in our conscious when some kid ends up in the burn unit at the local hospital because you didn’t want us to report a missing TPRV tube.
Gregg, I totally agree. I am a retired Fire Captain. I dont usually give this out as some find it a conflict. I ran my business while being employed with the city. Risk mitigation is the best way to explain both careers. You are on the spot. Push for the issues that cost lives and safety and push for what will cost the client the most. The other stuff is what it is. Thanks folks!
In the real world, when a water heater heating element fails, there are paths for the current to return to its source to trip a breaker or blow a fuse.
In a perfect world, all metal components of everything everywhere would be bonded, thus providing a continuous equipotential plane and a reliable universal ground reference. However, we live in a world that is far from perfect. We have to have a reasonable balance between the theoretical and the practical. Not everyone will agree where that balance point is.
As a practical matter, isolated metal components, including sections of metal pipes, within a building are not bonded to everything else. Under the right circumstances, anything metal has the potential to become energized. As a practical matter, however, individual isolated items have a very low probability of becoming energized; while very large components and systems have a greater likelihood of becoming energized.
Therefore, bonding together all metal components will not hurt anything, but not bonding something that is isolated from the source of electricity is an extremely low risk because there is no effective current path except under extraordinary circumstances.
No model code, building code, electrician, or engineer can foresee every possible set of circumstances. In the electrical world, more than any other aspect of building construction, there are wide margins of safety that go into the design of components and the model codes.
A good example is with the very conservative amperage values assigned to electrical conductors. For example, you could put a #14AWG conductor on a 20A circuit and with the circuit fully loaded, in most circumstances, there would never be a problem (if everything is properly assembled).
In my example of conductor sizes there are MANY variables that are taken into account statistically when assigning ampacities. It isn’t possible to know all the variables for every installation. Engineers take an aggregate average of all reasonably anticipated variables when determining ampacity.
Bonding is no different. To put it in simple terms. Let’s say that there is a small metal component that is not in close proximity to anything that is electrically conductive. We will assign it a risk value of one. It is at one end of the spectrum. The cold water system may be a thousand times more likely to become energized.we will assign it a risk value of 1000 (I’m making up these numbers for illustration purposes). For purposes of my illustration, we will assign everything else that is conductive in the house a value of between one and one thousand. Taking into account engineering, financial considerations, and all other practical considerations, including the fact that infinite precision comes at infinite cost, we have to decide where the dividing line is.
The National Electrical Code, the National Electrical Safety Code, the IEEE standards, and other model codes and standards are based on an ever increasing statistical body of knowledge. That’s one of the many reasons that model codes and other standards change over time.
Electrical fire investigators analyze the causes of fires, and to the best of our ability, we relate what we find to the surrounding environment (the insurance industry pays for more than 99% of the work). That information is collected in databases that are shared, not only with the insurance industry, but with associations such as the National Fire Protection Administration and the International Code Council, among others.
The good news for you is that it is well outside the scope of a home inspection to identify all those items that should reasonably be expected to be bonded together. If you were to see, for example, a section of pipe, one end of which is visible and connected to PEX, and the other end disappearing into an area where you don’t have access, it may be that the pipe you see should be bonded or it may be that it doesn’t need to be bonded. That’s not our concern as home inspectors. Only when, and if, if it is visible and obvious that it is within the home inspectors area of concern. Anything beyond that would require a specialist.
That’s common. I’ve worked in several communities where a second made electrode is mandatory regardless of soil conditions or anything else and others where they don’t care.
When the second made electrode became an NEC thing, the city where I did most of my work was divided on the subject. We had to install a supplemental rod in some parts of town, but not in others. The problem for us was that inspectors would sometimes go on vacation or call in sick. We would occasionally get inspectors from another neighborhood and who had different requirements. That’s just one of the challenges of being an electrical contractor. Fortunately, it’s outside the purview of a home inspector.
A ground rod has absolutely nothing with clearing a fault, but adding bonding around a section of non metallic pipe where the system is mostly metallic is a good idea,IMO. BTW, Sharkbite® fittings do isolate pipe also, if you do not believe me, put copper pipe into a Sharkbite® coupling & check for continuity afterward.
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