I have questions about the reason for water line bonding and when it is required. Lets take a 1970’s residential structure. Home has copper water pipes (galvanized would likely mean the same thing). Here are my questions. Thanks for your time.
Why is water line bonding required?
Is it required if 2 ground rods are installed 8’ deep and 8’ apart or if a UFER is in place?
What if a plumber comes in and installed Pex pipes under home after the water heater (or before and after) but only in a section so there is copper pipe before and after the pex? Would an additional bond be needed between both sections of copper pipe as well as the feed from the street?
What if the water heater is gas or electric? The element can provide electricity into the water pipe in a element failure but what about gas?
What if the plumber replaced the feed from the street with pex but attached to the copper distribution under the home. Would a water bond be required?
Your “what if” scenarios are confusing me but here’s what I keep in my mind when inspecting:
Metal water pipe into the earth was often used as a means of GROUNDING. If that is interrupted a new GROUNDING method/system is needed.
If a plastic water service pipe is installed (and eliminates the GROUNDING path) but metallic branch piping remains throughout the house, it must be BONDED to help reduce any charge it might carry.
It really comes down to GROUNDING v. BONDING. Once the line to the house is cut it is no longer a means of GROUNDING but the remaining metallic piping throughout the house should be BONDED (via the new GROUNDING system).
Morning, Greg.
Hope this post finds you well.
As to your questions. Lets start with, Why is water line bonding required?
Answer: The main purpose of this ground/bond is to ensure that the metal water pipe is at the same zero voltage to ground as the service grounded conductor.
Grounding: a low-resistance path for electricity to flow into the ground.
Answer: Section 250.50 of the National Electrical Code (NEC) requires that a metal underground water pipe in direct contact with the earth for at least 10 feet or more be used as one of the grounding electrodes for the electrical service to the building.
As for UFER and Grounding Electrodes. Any one of the (3) grounding methods is acceptable.
I rarely see UFER unless I am doing a commercial inspection or a very large home with high ampacity feed, and have never seen 2 Grounding Electrodes, let alone been able to measure depth and width for accuracy.
Main domestic water supply is what I typically see during a home inspection. Example below.
There are two separate requirements in your questions. The first requirement is does the underground metal water pipe qualify as a grounding electrode? That means that it needs to have 10’ or more in contact with the earth. If yes then it is required to be used as part of the structure GES (grounding electrode system). Since it may get replaced with a non-metallic underground pipe the NEC requires the water pipe electrode to be supplemented by an additional electrode. That is typically two ground rods minimum 6’ apart or a CEE. If the water pipe is non-metallic then either the ground rods or the CEE will qualify as the GES. No other electrodes would be required.
If the water pipe does not qualify as an electrode but the structure has a metal water piping system then that system is required to be bonded. The key word is system. Small sections of metal water pipe when interspersed with non-metallic piping are not a system and do not require bonding,
Never said it did.
Electrical grounding is a backup pathway that provides an alternating route for the current to flow back to the ground if there is a fault in the wiring system** .
Hope that helps.
Morning, Jim.
Grounding: a low-resistance path for electricity to flow into the ground.
Lets us go further… Electricity always returns to the source of the power supply (a transformer or substation.) Electric current will use the paths of least resistance to return to the source.Electrical systems and supply systems are grounded to the earth. Grounding is necessary to ensure safety and reliability.
In electrical engineering, ground or earth is a reference pointin an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth.
Not until you STOP with your incessant ‘Copy&Paste’ addiction and learn the topic at hand for yourself!
This is why you constantly have to come back and justify or explain your posts… you simply don’t understand the content of what you post!!
It certainly helps when someone who does the copy and paste routine to provide some context as to where the information is coming from and to use the quote feature to identify what they have copy and pasted. Often the information is incorrect and no one knows what the source is. To intersperse incorrect quotes in with your own content makes the content confusing, unreadable, and inaccurate.
The earth is a poor conductor and is not used used a return path for normal electrical current. It also cannot be relied upon to open an OCPD.
2020 NEC:
250.4(A)(5) Effective Ground-Fault Current Path.
Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.
Hi all, I apologies for not responding as I was on vacation and I find it important to step away from the business when on vaca. Anyway thanks for your responses.
The concept of grounding was well covered in this thread. However, I did ask other questions that did not get an answer so I will post them here. Hopefully you can help me clear up these questions:
"What if a plumber comes in and installed Pex pipes under home after the water heater (or before and after) but only in a section so there is copper pipe before and after the pex? Would an additional bond be needed between both sections of copper pipe as well as the feed from the street?
What if the water heater is gas or electric? The element can provide electricity into the water pipe in a element failure but what about gas?
What if the plumber replaced the feed from the street with pex but attached to the copper distribution under the home. Would a water bond be required?
[quote=“Greg Sanberg, OHCI 1339, post:20, topic:221619, username:gsanberg”]
"What if a plumber comes in and installed Pex pipes under home after the water heater (or before and after) but only in a section so there is copper pipe before and after the pex? Would an additional bond be needed between both sections of copper pipe as well as the feed from the street? [/quote]
Yes.
[quote=“Greg Sanberg, OHCI 1339, post:20, topic:221619, username:gsanberg”]
What if the water heater is gas or electric? The element can provide electricity into the water pipe in an element failure but what about gas? [/quote]
Huh? The question makes no sense. If the water heater is electric, it uses electricity to heat the water. If it is gas, it uses gas to heat the water. Gas can’t “Provide electricity into the water pipe”.
