Water pipe bond [Archive] - InspectionNews

Gunnar Alquist

02-06-2011, 12:46 AM

Isnt the water pipe bond (GEC) supposed to be within 5' of pipe as it enters the structure?

Yes. It has been that way for a number of years. However, I am not sure that was always the case. I just glanced in my 1965 NEC and could not find any specifics. Might be there, but I could not find it.

I am not sure why that requirement. Bonding would work just as well at the water heater or any other location. The only reason that I can think of is for easy identification by the inspector. That way he/she does not need to search around for it.

What is missing from the posted picture is the hot/cold bond. The previous post indicates that the gas is bonded, but I do not see it in this pic. Did you change pics?

ken horak

02-06-2011, 06:53 AM

The requirement for the grounding electrode conductor to be attached to the incoming (metallic) water line, within 5' of the point of entrance was new in the 2002 NEC.

The reason of using the first 5' is based on people replacing a peice of the copper piping with plastic.
The purpose of this means of grounding is not so much to bond the piping but rather to use the underground metallic pipe as a grounding electrode ( much like a ground rod)

Lets say that the point of attchment is at the water heater. The homeowner then fixes a leak by installing a short piece of plastic piping. This fix is between the water heater and where the water pipe enters the structure. You have just lost the water pipe as a grounding electrode

The requirement is not so the inspector can locate it. If an inspector can not locate it , they should require the contractor to be present and to show them the connection. Trust me this has happened :D

Speedy Petey

02-06-2011, 07:22 AM

Yes. It has been that way for a number of years. However, I am not sure that was always the case. I just glanced in my 1965 NEC and could not find any specifics. Might be there, but I could not find it. This is not correct since he specifically asked about a water bond.
There is NO requirement that a water pipe bond be made within 5'. That requirement is ONLY if the water pipe in question also being used as a grounding electrode. THEN the 5' rule applies.

I am not sure why that requirement. Bonding would work just as well at the water heater or any other location. The only reason that I can think of is for easy identification by the inspector. That way he/she does not need to search around for it. See above. ;)
The water bond is only required to be accessible.

What is missing from the posted picture is the hot/cold bond.
There is no such requirement. Hot pipes are inherently bonded through mixing valves and other parts of the system. There is NO requirement for an external intentional bonding jumper.

ken horak

02-06-2011, 09:38 AM

Speedy makes a good point.
The original post does say water bond
BUT...

The original post also states GEC as in Grounding Electrode Conductor.

Now we need some clarification on the original post, Just which is it he is asking about? Is he asking about Bonding the water pipes or asking about the connection of the Grounding Electrode Conductor ?
He does mention the rule of requiring the GEC to within 5' of the entrance of the water line into the strucutre, this and the mention of the GEC leads one to think he is talking about the service grounding using the incoming metallic water line.

This why it is so very important that people use the correct terminology

Speedy Petey

02-06-2011, 10:57 AM

The original post does say water bond
BUT...

The original post also states GEC as in Grounding Electrode Conductor.
LOL, good point. I glanced right over that. :p

Jerry McCarthy

02-06-2011, 12:16 PM

All "metallic systems" in a home that are capable of being energized are required to be bonded to the grounding system. This is usually taken to mean: metallic water supply, metallic drain-waste-vent pipe, metal ducting, gas lines, and sometimes metallic structural elements (eg: metal framing systems).

The rationale for this is simple: if somehow a hot conductor contacts a water pipe, say, you don't want every plumbing fixture in your home to become live. The bonding attempts to ensure that you have a low resistance path to the ground system at the panel, and thence to the neutral - ensuring that this ground fault is stopped by a breaker or fuse tripping. Remember that this is independent of the grounding electrode system's conductivity.

Our National Electric Code requires that each electrically isolated section of metallic water pipe must be jumpered (bonded) together. This means that you are required to provide a jumper wire that bypasses the main water meter (especially if you're using the water supply line as a grounding electrode), and a jumper between hot and cold if the water heater is an electrical insulator. The National Electric Code for example, also requires that the frame of your clothes washer be bonded to the cold water supply pipe.

Ref: NEC 2008 – 250.104

Speedy Petey

02-06-2011, 02:27 PM

There is no requirement for an additional external jumper from hot to cold, nor is there a requirement for a jumper to a gas pipe.

Gunnar Alquist

02-06-2011, 02:54 PM

There is no requirement for an additional external jumper from hot to cold, nor is there a requirement for a jumper to a gas pipe.

On the hot/cold, that would be up to interpretation. Around here, the AHJ requres hot/cold bonding because they view the hot and cold as separate water systems.

(A) Metal Water Piping. The metal water piping system
shall be bonded as required in (A)(l), (A)(2), or (A)(3) of
this section. The bonding jumper(s) shall be installed in
accordance with 250.64(A), (B), and (E). The points of
attachment of the bonding jumper(s) shall be accessible.

(1) General. Metal water piping system(s) installed in or
attached to a building or structure shall be bonded to the
service equipment enclosure, the grounded conductor at the
service, the grounding electrode conductor where of
sufficient size, or to the one or more grounding electrodes
used. The bonding jumper(s) shall be sized in accordance
with Table 250.66 except as permitted in 250.104(A)(2)
and (A)(3).

On the gas pipe, I disagree.

(B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure, the grounded
conductor at the service, the grounding electrode conductor
where of sufficient size, or the one or more grounding
electrodes used. The bonding jumper( s) shall be sized in
accordance with 250.122, using the rating of the circuit that
is likely to energize the piping system(s). The equipment
grounding conductor for the circuit that is likely to energize
the piping shall be permitted to serve as the bonding
means. The points of attachment of the bonding jumper(s)
shall be accessible.

James Duffin

02-06-2011, 05:11 PM

On the hot/cold, that would be up to interpretation. Around here, the AHJ requres hot/cold bonding because they view the hot and cold as separate water systems.

(A) Metal Water Piping. The metal water piping system
shall be bonded as required in (A)(l), (A)(2), or (A)(3) of
this section. The bonding jumper(s) shall be installed in
accordance with 250.64(A), (B), and (E). The points of
attachment of the bonding jumper(s) shall be accessible.

(1) General. Metal water piping system(s) installed in or
attached to a building or structure shall be bonded to the
service equipment enclosure, the grounded conductor at the
service, the grounding electrode conductor where of
sufficient size, or to the one or more grounding electrodes
used. The bonding jumper(s) shall be sized in accordance
with Table 250.66 except as permitted in 250.104(A)(2)
and (A)(3).

On the gas pipe, I disagree.

(B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure, the grounded
conductor at the service, the grounding electrode conductor
where of sufficient size, or the one or more grounding
electrodes used. The bonding jumper( s) shall be sized in
accordance with 250.122, using the rating of the circuit that
is likely to energize the piping system(s). The equipment
grounding conductor for the circuit that is likely to energize
the piping shall be permitted to serve as the bonding
means. The points of attachment of the bonding jumper(s)
shall be accessible.

Is that 250.64 from the 2008 NEC? I don't see where it mentions bonding the hot and cold but I could have missed it.,

Speedy Petey

02-06-2011, 07:08 PM

On the gas pipe, I disagree.

(B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure, the grounded
conductor at the service, the grounding electrode conductor
where of sufficient size, or the one or more grounding
electrodes used. The bonding jumper( s) shall be sized in
accordance with 250.122, using the rating of the circuit that
is likely to energize the piping system(s). The equipment
grounding conductor for the circuit that is likely to energize
the piping shall be permitted to serve as the bonding
means. The points of attachment of the bonding jumper(s)
shall be accessible.You are overlooking the part I made bold and underlined.

Speedy Petey

02-06-2011, 07:10 PM

On the hot/cold, that would be up to interpretation. Around here, the AHJ requres hot/cold bonding because they view the hot and cold as separate water systems. I think it is a stretch to consider the hot and cold separate systems. Just MHO.
Then again, I have heard about how some inspectors like to make things up.

Speedy Petey

02-06-2011, 07:30 PM

Then again, I have heard about how some inspectors like to make things up.Sorry, by this I mean AHJ's.

Jerry Peck

02-06-2011, 08:27 PM

There is no such requirement. Hot pipes are inherently bonded through mixing valves and other parts of the system. There is NO requirement for an external intentional bonding jumper.

That is debatable ... when there are no mixing valves, or when there is CPVC in the system beyond the copper, or when the risers are PVC/PB/etc ... there is no inherent bonding to the hot water pipe - and THAT IS required to be bonded, and thus if there is no evidence showing that it is bonded, then it needs a bond.

Marc M

02-07-2011, 12:48 AM

Sorry for the delay but I cant post the image that I want to use. I am trying to change its format. It's an image of a #10 bare copper running from the SEP to the middle of the garage and attached to the (recently re-piped) copper main. 10' from where it enters into the garage/structure.
Hows the mental image?;)

Speedy Petey

02-07-2011, 04:50 AM

That is debatable ... when there are no mixing valves, or when there is CPVC in the system beyond the copper, or when the risers are PVC/PB/etc ... there is no inherent bonding to the hot water pipe - and THAT IS required to be bonded, and thus if there is no evidence showing that it is bonded, then it needs a bond.Oh, I totally agree. The requirement is definitely that the pipes be bonded. It's my job to make sure that they are.
My point was there is no express and specific requirement that there be a hot/cold jumper.

Darren Miller

02-07-2011, 05:10 AM

My point was there is no express and specific requirement that there be a hot/cold jumper.

The state of New Jersey would disagree with you.

Speedy Petey

02-07-2011, 05:40 AM

The state of New Jersey would disagree with you.They are talking about a gas pipe bond, not a hot/cold jumper. They are referencing 250.104(B) same as in this thread. See post #13.

If the only gas appliance is a water heater with no electric then yes, a bond, or bonding jumper, is required.

bob smit

02-07-2011, 02:39 PM

State of Mi sent our Building Dept a notice to require bonding the csst when installed, at the connector (not the pipe itself obviously) or the gas pipe immediately ahead of the connection.

The manufacturers are also requiring this, so, 110.3(b) says....

James Duffin

02-07-2011, 02:46 PM

NC requires the gas piping to be bonded at the gas meter when csst is used in the system.

bob smit

02-07-2011, 03:16 PM

NEC 110.3(b) equipment installed to manufacturers specs.
Flexible Corrugated Gas Piping from Gastite: Underground Gas Piping Products and Accessories (http://www.gastite.com/bonding.php)

Jerry McCarthy

02-07-2011, 04:40 PM

I suspect we are talking apples and oranges Speedy? Bonding – 2009 IRC E36-9.6 & 3609.7 – NEC 1999 250.104 – 2008 250.104 - NEC 1987 250.80 all basically say the same. In California home inspectors write-up lack of boding at the metal water & gas piping at the water heater every day. The main reason for the jumper between the hot & cold water supply piping is due to the water heater usually has dielectric unions installed at the water heater tank’s nipples to help prevent corrosion, which of course interrupts the bond.

Gunnar Alquist

02-07-2011, 04:51 PM

You are overlooking the part I made bold and underlined.

I guess I am not sure I understand exactly what that sentence means. If it refers to the ECG from a furnace (or gas range/cook top), then I think I get it. However, I frequently see NM lying over gas pipe in an attic. I would assume that this could energize the gas piping, should the NM sheathing and insulation become damaged. This may not be "likely to energize the piping", but I seen rodent gnawed NM in attics frequently enough that I would think that it is possible and bonding would be a requirement.

Gunnar Alquist

02-07-2011, 05:53 PM

If I may, I would like to hijack this thread. This is sort of related and I did not feel like beginning another.

Home today had a solar photovoltaic system on the roof. The inverter had its own grounding electrode (ground rod). The feeder from the inverter to the service equipment had a grounding conductor. The home was (presumably) grounded with a concrete encased electrode (ufer).

My understanding is that if more than one grounding electrode is used, they must be bonded together. Is an additional bond required or is the grounding conductor that they used sufficient? I do not recall the size of the wire, but since the circuit breaker is 35 amp, I would guess a #8. Should a #6 be used?

An unrelated question regards the circuit breaker in the service equipment for the PV system. Since the breaker is backfed, it should be secured. Am I correct?

Jim Port

02-07-2011, 05:55 PM

James Duffin

02-07-2011, 06:09 PM

Ted Menelly

02-07-2011, 06:15 PM

250.104 does not say you have to bond the hot to the cold water line at a water heater. Not sure where this information is coming from unless it is a state requirement. Also most water heaters do not need dialectic unions unless galvanized piping is installed...which is rare these days.

The water lines are bonded back to the panel. No jumper to the hot side and the hot water pipes do not get bonded back to the panel. Water pipes should never be used as a ground as at any time the lines in the ground could be pulled out and non ferrous pipes installed. Whether it is code in your srea or not to have copper to the home anyone can change it out. It may not be changed out by a plumber that may know what he is doing.

If there is no ground rod in older homes I inspect and there is just the water lines being used as a ground I write it up every time as the ground rod not installed.

Gunnar Alquist

02-07-2011, 06:18 PM

Gunnar, read the underlined portion. The gas piping is already considered bonded by the EGC run in the circuit.[/FONT]

Jim,

Yes, I did understand that part. The part that I do not understand is how do I know which circuit is "likely to energize the gas piping"? Is it the one that is connected to the furnace, cook-top or range? Or, is it the cable that is resting on the gas pipe in the attic? If the appliance, then I understand. If it is the cable in the attic, then I do not. My sticking point is the word "likely". Logically speaking, an insulated cable is not "likely" to energize a pipe. But as I said, I do see rodent damaged cable sheathing and wire insulation in attics occasionally. Maybe the codes are not planning on this type of damage.

Nonetheless, as has been said, in CA, bonding is installed on the gas piping (generally adjacent to the meter), on the cold water supply piping, and a jumper is provided between the cold/hot at the water heater. CA uses the 2008 NEC, and I do not believe that it has been edited/changed.

Jerry Peck

02-07-2011, 06:31 PM

My point was there is no express and specific requirement that there be a hot/cold jumper.

Actually, the requirement is the reverse of what you are saying: the requirement is to bond it ... unless one proves it is bonded through other parts of the system.

Think of it as installing a driven ground rod ... you will be installing a supplemental second ground rod *unless* you prove that the first ground rod has less than 25 ohms to ground. Only in this case you are bonding the interior metal water piping system - cold *and* hot, unless you prove the hot is bonded through interconnections of the piping system.

Maybe I was from Missouri in a former life, but "show me" it is (either the ground rod has 25 ohms or less to ground, or, the hot piping is bonded through the cold piping).

Jerry Peck

02-07-2011, 06:41 PM

Gunnar, read the underlined portion. The gas piping is already considered bonded by the EGC run in the circuit.

(B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including
gas piping, that is likely to become energized shall be
bonded to the service equipment enclosure, the grounded
conductor at the service, the grounding electrode conductor
where of sufficient size, or the one or more grounding
electrodes used. The bonding jumper( s) shall be sized in
accordance with 250.122, using the rating of the circuit that
is likely to energize the piping system(s). The equipment
grounding conductor for the circuit that is likely to energize
the piping shall be permitted to serve as the bonding
means. The points of attachment of the bonding jumper(s)
shall be accessible.

Okay, now taking Gunnar's example of the NM cable in the attic ... define:

the circuit that is likely to energize the piping

The equipment grounding conductor for THAT CIRCUIT "shall be permitted to serve as the bonding means", and how does the equipment grounding conductor for THAT CIRCUIT get connected to the gas pipe to be used for that bonding?

I'm looking at a new construction house trying to determine *which* of the circuits may be "the circuit that is likely to energize the piping" and use to determine the size of the bonding conductor.

Currently, a #12 AWG bonding conductor was attached to the rigid piping to which the CSST is connected to and the #12 bonding conductor was then run back to the panel.

Jerry Peck

02-07-2011, 07:14 PM

This answers my question, and that of others regarding bonding of CSST. This is from the updated 08/2010 Design and Installation Guide for Gastite CSST: (note: the larger bold type is in the Design and Installation Guide, I have highlighted with red)

The piping is permanently and directly connected to the electrical service equipment enclosure, the grounded conductor at the electrical service, the grounding electrode conductor (where of sufficient size) or to one or more of the grounding electrodes used. For single and multi-family structures, a single bond connection shall be made downstream of the individual gas meter for each housing unit and upstream of any CSST connection. The bonding conductor shall be no smaller than a 6 AWG copper wire or equivalent. The bonding jumper shall be attached in an approved manner in accordance with NEC Article 250.70 and the point of attachment for the bonding jumper shall be accessible. Bonding/grounding clamps shall be installed in accordance with its listing per UL 467 and shall make metal-to-metal contact with the piping. This bond is in addition to any other bonding requirements as specified by local codes.

That tells WHERE the bonding jumper is to be connected.

That also tells the MINIMUM SIZE the bonding jumper is required to be.

And that tells us that those requirements are IN ADDITION TO the requirements of other codes, which would include the NEC.

James Duffin

02-07-2011, 07:30 PM

The water lines are bonded back to the panel. No jumper to the hot side and the hot water pipes do not get bonded back to the panel. Water pipes should never be used as a ground as at any time the lines in the ground could be pulled out and non ferrous pipes installed. Whether it is code in your srea or not to have copper to the home anyone can change it out. It may not be changed out by a plumber that may know what he is doing.

If there is no ground rod in older homes I inspect and there is just the water lines being used as a ground I write it up every time as the ground rod not installed.

If you attach copper pipes to a steel hot water tank you don;t need the jumper. If you have a fiberglass or plastic tank you would need the jumper.

bob smit

02-07-2011, 08:33 PM

If U have not clicked on the link I provided earlier, here is the exact link:
http://www.gastite.com/include/languages/english/downloads/pdfs/TB2010-01.pdf

Gunnar Alquist

02-07-2011, 08:41 PM

If you attach copper pipes to a steel hot water tank you don;t need the jumper. If you have a fiberglass or plastic tank you would need the jumper.

Fair enough, except that in CA (where the earth moves... under my feet... sorry), most of the water heaters that I see are connected with flexible connectors (for obvious reasons). These generally have a dielectric fitting where they attach to the water heater.

James Duffin

02-07-2011, 08:59 PM

I concere....it sounds like a regional issue then.

James Duffin

02-07-2011, 09:02 PM

If U have not clicked on the link I provided earlier, here is the exact link:
http://www.gastite.com/include/languages/english/downloads/pdfs/TB2010-01.pdf

I read that....in NC we are required to bond the gas piping at the meter. It has nothing to do with the water lines.

Jerry Peck

02-07-2011, 09:22 PM

If U have not clicked on the link I provided earlier, here is the exact link:
http://www.gastite.com/include/languages/english/downloads/pdfs/TB2010-01.pdf

Bob,

That technical bulletin is superseded by the Design and Installation Guide I quoted from as the technical bulletin has an older date of publication than does the Design and Installation Guide.

Hard to keep up with rapid changes when things like that bonding happen and then change until they think they get it right ... until they find a different way to make it 'right'. ;)

bob smit

02-08-2011, 09:32 AM

Right on J.P., the link I found is not even the one the MI Electrical Division sent my department stating that the bond connection to be on the fitting or just in front of the fitting (upstream).
The point I was desperately trying to make... in addition to any local requirement: Manf-spec's in installation are still required per 110.3(b).

James Duffin

02-08-2011, 11:37 AM

Here is what NC requires> It sounds like MI is different.

SECTION 310 (IFGS)
ELECTRICAL BONDING

310.1 Gas pipe bonding. Each above-ground portion of a gas
piping system that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping shall be considered to be bondedwhere it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance.

NEW CSST RULE!

The effective date of this Rule is December 1, 2009.
The Statutory authority for Rule-making is G. S. 143-136; 143-138.

2009 NC Fuel Gas Code
310.2 CSST Bonding. (090310 Item B-2)

310.2 CSST Bonding. CSST Gas piping systems shall be bonded to the electrical service grounding electrode system at the point where the gas service enters the building. The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent.

Jerry McCarthy

02-08-2011, 11:53 AM

Also most water heaters do not need dialectic unions unless galvanized piping is installed...which is rare these days.[/QUOTE]

James, the CW dip tube and HW outlet piping is galvanized metal at least 99% of the water heaters I've seen. The dielectric fittings they put on them is to resist corrosion, but also in effect blocks any bonding in place, hence - the bonding jumper.

James Duffin

02-08-2011, 01:33 PM

Also most water heaters do not need dialectic unions unless galvanized piping is installed...which is rare these days.

James, the CW dip tube and HW outlet piping is galvanized metal at least 99% of the water heaters I've seen. The dielectric fittings they put on them is to resist corrosion, but also in effect blocks any bonding in place, hence - the bonding jumper.

They are dielectric nipples.....not galvanized.