Bonding water pipes

WillK

Okay, let me see if my plan sounds okay by describing what I have and what I think I need to do. The new 200 amp service I am installing, the water meter and the water heater are presently all in the same 10x10 utility room. The old 100 amp main panel is in a different room (bedroom).

My permit history search uncovered no electrical permits on the house. Ever. Since it was built in 1917. The 100 amp panel is a Square D Homeline panel, the home inspector believed it was probably done professionally.

The house has a dirt floor crawlspace, the closest thing there is to something which could be called a foundation is 3 footings supporting piers of concrete blocks under the center beam. The remainder of the house support comes from columns of cement blocks set directly on dirt. The city water comes out of the ground in the middle of the crawlspace and passes through the wall into the utility room where the meter is located.

The utility room is slab on grade with brick wall over wood frame.

From the utility room, you go through a door openning into the kitchen. On one side is the water meter, the other side the water heater.

There is no apparent ground connection to the water piping, the old 100A panel does have a wire to at least 1 ground rod, can't tell if a second was installed. There is a bonding jumper across the meter, but it only jumps over the meter and does not connect to anything.


Here is what I would like to do: I would like to run my #4 copper wire up, through the attic of the utility room, then down. I will remove the old meter jumper and reuse both clamps, passing the #4 through both clamps and then under the step and to the outlet side of the water heater.

I assume that since the water heater and the meter are so close together that bonding to the cold water pipe at the water heater would be redundant and not required.

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__________________
Please do NOT consider any "before" picture of my house as any kind of endorsement of any particular construction method. In fact, you should probably assume that if I post a "before" picture, I am posting it because I am soliciting advice on a proper replacement for one of MANY things done wrong by a previous owner.

hpp58

Bond the hot and cold pipes of the water heater. It is required.

Speedy Petey

WillK, WHY start a new thread on this??? You already have one going here: Wire size for grounding to water meter?

Speedy Petey

Can you point to this in the code for me?

hpp58

Give me fighting chance, I try to find out where tomorrow.

Speedy Petey

I'll give you a hint.
It's not in the NEC.

WillK

The thing is, there is all of 6' of cold water pipe between the water heater and the meter. In my plan, the cold water pipe is bonded near the meter. It's all copper pipe with no discontinuities.

__________________
Please do NOT consider any "before" picture of my house as any kind of endorsement of any particular construction method. In fact, you should probably assume that if I post a "before" picture, I am posting it because I am soliciting advice on a proper replacement for one of MANY things done wrong by a previous owner.

WillK

Strictly speaking, the topic of the other thread was more regarding the wire size. I didn't realize until AllanJ's response that there was more to this than just a wire from the new panel to the water meter, particularly since the old panel wasn't necessarily bonded properly or if it was than it was done to an older code revision that didn't require the water pipes bonded at the meter or water heater.

Since I'm meandering, 250.104(B) has me confused too because I thought that grounding to the gas piping is a no-no... But 250.104(B) says any metal piping likely to become energiezed must be bonded - and it explicitly says that this includes gas piping. Does this mean the gas pipe must be bonded, or is this something that only applies in certain cases???

__________________
Please do NOT consider any "before" picture of my house as any kind of endorsement of any particular construction method. In fact, you should probably assume that if I post a "before" picture, I am posting it because I am soliciting advice on a proper replacement for one of MANY things done wrong by a previous owner.

hpp58

I know. I think we all got reminded by an inspector when we didn't install it. 250.104(A)(1) is pretty darn close.

zpm

Your gas pipe is bonded by default by any gas appliance (HWH, HVAC, range) that has an electrical connection or metal water pipe connection. Your gas isn't bonded if you only have an old range with a pilot light. Or you only have a gas HWH and PEX/plastic pipe.

Your hot water piping is also bonded by default by any metal plumbing fixture, like a shower mixing valve. A bond may not occur at the HWH if your connections to the HWH have dielectric couplings or non-metallic flex hoses.

Its quite reasonable to bond the gas or hot water on a case by case basis.

__________________
Honey, does this tool belt make me look FAT?

Speedy Petey

250.104(A)(1) is extremely general, and does not specifically state that a hot/cold jumper is required. NO WHERE does it state it is required.

Show me a house where you think it is required, and I'll show you a house with a shower/tub valve, a boiler, or any number of other things that creates this bond.
The jumper is simply NOT required by code, although some inspectors do like to play CMP and ask for it any way.

NJMarine

The use of dielectric fitting and when the hot water heater is removed can cause the pipes to energized. There have been cases where plumbewrs removed a hot water heater and while working on other plumbing got shocked. Bonding the hot water heater eleiminate this problem.
Other codes are used in also such as IRC and IBC. Depending on your loaction and what codes in addition are being used, will dictate whether this bonding jumper is needed. IMO it is not a big deal to install this bonding jumper. 2 clamps, piece of wire and 5-10 minutes of time. InNJ it is required.

Below is the commentary in regards to bonding of metal pipies. It is from 2002 but still is accurate.

NEC 2002 HANDBOOK COMMENTARY;

Bonding the interior metal water piping system is not the same as using the metal water piping system as a grounding electrode. Bonding to the grounding electrode system places the bonded components at the same voltage level. For example, a current of 2000 amperes across 25 ft of 6 AWG copper conductor produces a voltage differential of approximately 26 volts. Section 250.104(A)(1) requires the interior metal water piping system and any other metal piping systems likely to become energized to be bonded to the service equipment or grounding electrode conductor.
If it cannot reasonably be concluded that the hot and cold water pipes are reliably interconnected, an electrical bonding jumper is required to ensure that this connection is made. Some judgment must be exercised for each installation. The special installation requirements provided in 250.64(A), (B), and (E) also apply to the water piping bonding jumper.

Speedy Petey

The handbook commentary is NOT the code and is NOT enforceable. It is simply commentary. Don't get me wrong though, I use it myself quite often.

Sure, "it cannot reasonably be concluded that the hot and cold water pipes are reliably interconnected", but it CAN be confirmed by checking that the items I mentioned are present in the house.
If this were the case WHY is it not required in the code itself???

Do you refute the fact that a shower mixing valve does physically, mechanically and electrically bond the hot and cold piping systems???

NJMarine

It is not enforcable, bjut gives an rationale for doing something. In NJ if a fine print note refers to another code than that is enforcable. In addition to the NEC we have to follow other codes as well. Such as the IBC, mechanical code and model energy code. These have requirements that are not in the NEC, but are enforcable.
The NEC does not state where IC or non IC cans be used, but does say about insulation near the cans. The energy code says where IC need to be used.
Everything we do is not soley based on only the NEC.

Speedy Petey

Yes, I am aware of all of these things. Thank you.

Now then, where in the IBC, mechanical code or model energy code do find this requirement for a hot/cold jumper?