Residential Grounding Requirements. (NEC)

[gaalcom]

I'm prepping to replace my copper water piping with PEX and have a question about the electrical panel grounding that currently terminates at the pipes.

The main electrical panel currently has 3 GECs coming out, two are 4ga solid while one is 6ga stranded. One 4ga and the 6ga are clamped to copper water pipes while the other 4ga leads outside to a driven rod. I assume this arrangement is code as an inspection was performed after the heavy-up was installed about 10 years ago. Probably should mention before asking my question(s) -- It's a 200a with 2/0 SE and residence is in MD.

What I'd like to know is what might be the best options for grounding after PEX retrofit? I can replace the 6ga pipe terminated ground wire and run a new 4ga an additional 10ft to the one remaining length of copper water pipe at its point of entry. That leaves the other 4ga homeless. Can this also be run to the same only remaining copper pipe or maybe routed outside and rodded with proper distancing? Heck, do I even require three 4ga GECs? Pretty confident the 6ga is what was original to the home and am hoping it wasn't (and doesn't need to be) part of the equation.

Any insight is greatly appreciated.

 

[wyliesdiesels]

The wires going to the plumbing are not considered GECs unless the water line was being used as an electrode. in your case sounds like theyre just bonding wires.

its odd you have 2. really only need one but all metallic piping including gas lines need to be bonded.

 

[Zeke]

What are the minimum requirements for what seems to the the copper water service entering the building?

 

[gaalcom]

The wires going to the plumbing are not considered GECs unless the water line was being used as an electrode. in your case sounds like theyre just bonding wires.

its odd you have 2. really only need one but all metallic piping including gas lines need to be bonded.

Much appreciate the reply.

Interesting -- So I believe you're saying the copper to/from the water lines is simply a way to earth them and the panel is just a convenient point of termination? I see no bonding directly to the gas lines but as the water heater is gas I assume the bonding of the water line could encompass the gas? As I'm keeping the required 18"+ of copper at the water tank per PEX code I'll leave the current bond at that location.

Checking the ICC section E3603 (which MD uses for direction) I also see no use of plural when they designate grounding requirements so it seems, as you infer, only one 4ga ground should be required making the one going to the grounding rod outside enough. Out of curiosity -- The original 6ga ground/bond (also to a water pipe) is just above a metal I-beam that, at its center point, has a metal column into the concrete floor. Is it possible that that 6ga could be affixed to the I-beam and qualify as an additional ground?

I also made a mistake in my earlier post. The SE is 4/0 AL for the 200a service.

 

[75gmck25]

I live in Virginia, and have a 200 amp panel that was inspected when installed, and then later when the POCO service was moved to underground and they moved the meter. Most of my plumbing has also been renovated, and it's about 90% PEX.

I have a single panel ground wire running outside, but it's connected in a daisy chain with a solid ground wire to two ground rods. There is another solid ground/bond that goes over to the copper water pipe where it enters the house. When they installed the gas fireplace the gas pipe was also grounded/bonded to the panel.

 

[Zeke]

No the water lines to the WH are not necessarily bonded to the gas. IDK if you can use a jumper or not. But don't assume that the gas lines are bonded though what maybe CSST in your case. Need to attach to the hard pipe.

 

[wyliesdiesels]

water heater should have hot cold and gas all tied together

 

[larry4406]

In my neck of the woods (northern VA and MD), we don’t need to bond black iron pipe gas lines as the AHJ’s consider it’s bonded via the threaded connections to the appliance which is bonded by its ground from the wiring.

CSST we bond.

 

[wyliesdiesels]

In my neck of the woods (northern VA and MD), we don’t need to bond black iron pipe gas lines as the AHJ’s consider it’s bonded via the threaded connections to the appliance which is bonded by its ground from the wiring.

CSST we bond.

How do you bond a gas line in that regard when the appliance is connected to the iron pipe with a flex line? Every single gas appliance we have here is connected with a flex line. You never see iron pipe connected directly to the appliance.

 

[mm08822]

In my neck of the woods (northern VA and MD), we don’t need to bond black iron pipe gas lines as the AHJ’s consider it’s bonded via the threaded connections to the appliance which is bonded by its ground from the wiring.

CSST we bond.

That's like grounding a metal box using the the device yoke that has the cable ground only connected to the yoke.

How do you bond a gas line in that regard when the appliance is connected to the iron pipe with a flex line? Every single gas appliance we have here is connected with a flex line. You never see iron pipe connected directly to the appliance.

My furnace and HWH are hard piped, but I've seen many where the flex line is just waiting to get whacked. Nobody wants to thread pipe anymore. SMH!
With a basement, it is usually a piece of cake to bond the gas line close to point of entry.

 

[larry4406]

How do you bond a gas line in that regard when the appliance is connected to the iron pipe with a flex line? Every single gas appliance we have here is connected with a flex line. You never see iron pipe connected directly to the appliance.

Everything is hard piped. Furnaces, water heaters, etc. No flex lines except for the cooktop. The cooktop is grounded internally via its ground screw and ground prong.

 

[larry4406]

That's like grounding a metal box using the the device yoke that has the cable ground only connected to the yoke.

My furnace and HWH are hard piped, but I've seen many where the flex line is just waiting to get whacked. Nobody wants to thread pipe anymore. SMH!
With a basement, it is usually a piece of cake to bond the gas line close to point of entry.

I think not much different then using EMT to ground the box instead of pulling a separate ground.

Regardless, this is what the AHJ enforces in my area, so you do your thing there to keep your sheriff happy.

We use only threaded black pipe for gas in our homes. Very rarely do we use CSST. I detest CSST.

Yes finding good pipe thread crew is becoming difficult. Folks today just want to drag hoses.

 

[mm08822]

Unless VA has a written exclusion when adopting the NEC, metallic pipng systems are required to be bonded to the electrical system and I would expect it to be by a permanent means vs dependant on connected appliances.

 

[dave*99]

The introduction of CSST brought on some detailed bonding requirements. CSST is much more susceptible to lightning damage than iron pipe.
Here in an example requirements doc:

https://www.iccsafe.org/wp-content/uploads/membership_councils/CodeNotes_2015IFGC.pdf

YMMV

 

[gaalcom]

Thanks to all for the replies and general discussion, all insightful.

While I don't have any CSST I'd still like to tie in the gas piping. Since the WH and furnace are co-located and WH is already bonded directly to the panel could the furnace (gas piping in general) be bonded by clamping the black and copper together via two foot of 4ga? Didn't see code that required home-runs for each. Now that I think of it -- A more logical option would be to complete a home-run bond of the black pipe using the stranded ground wire that'll be coming off the soon to be removed copper. This is assuming the existing single 4ga to the ground rod is sufficient otherwise I'd run the stranded outside and rod it. Still would be interesting to know the answer to the struck question above.

I see 75gmck25 mentioned they daisy-chained ground rods. From what I understand doing that still qualifies as a single ground. Would the daisy be needed because the soil resistance provides below the 25-ohm requirement with a single rod?

After further code delving I see my question about using the metal I-beam/post as ground would be a no-go. Seems the concrete would require 20+ foot of dedicated acceptable electrode encasement.

 

[dave*99]

Would the daisy be needed because the soil resistance provides below the 25-ohm requirement with a single rod?

Sorta....
There are 2 options.....

Use a single ground rod and prove via testing that the impedance is below 25 ohms,

Or, install 2 ground rods with no testing required and ultimately no guarantee the impedance is less than 25 ohms.

 

[gaalcom]

Sorta....
There are 2 options.....

Use a single ground rod and prove via testing that the impedance is below 25 ohms,

Or, install 2 ground rods with no testing required and ultimately no guarantee the impedance is less than 25 ohms.

Ah, so banking on passing a visual inspection, no questions asked.

Thanks for the link to the ICC CSST update. Amazingly that was written in very plain English providing useful info.

 

[dave*99]

Ah, so banking on passing a visual inspection, no questions asked.

Thanks for the link to the ICC CSST update. Amazingly that was written in very plain English providing useful info.

My electric service and ground rods are on the north side of my house. Gas service is on the south side. A 4 gauge stranded bonding wire runs from a point just after the gas meter all the way across the house to the ground bus in my main service panel. Easy to see, understand and inspect.

 

[wyliesdiesels]

Everything is hard piped. Furnaces, water heaters, etc. No flex lines except for the cooktop. The cooktop is grounded internally via its ground screw and ground prong.

so what if all you have is gas cooktop with a flexible line? thats not a good way to bond a gas line

 

[larry4406]

so what if all you have is gas cooktop with a flexible line? thats not a good way to bond a gas line

I don't know know what to tell you other than that is what is enforced here. How is it any different than using EMT as the ground?

Washington Gas is the natural gas distributor in this area. Their contractor installation guide has this interesting requirement in it:


OP - wish you the best. I'm out.

 

[dave*99]

I don't know know what to tell you other than that is what is enforced here. How is it any different than using EMT as the ground?

Washington Gas is the natural gas distributor in this area. Their contractor installation guide has this interesting requirement in it:


OP - wish you the best. I'm out.

You know your turf better than I, but let me respectfully ask this question:

In my area, the gas piping system is bonded after the meter. The gas service comes through the regulator, meter and connects to the customers piping. The bonding is done on the customers piping at that point. It doesn't matter if you have iron pipe or CSST. That is the bond point and it serves the entire gas system. The bond is not connected to the gas utility equipment.

Our underground gas lines are plastic. If I were to bond to the meter instead of the customer piping, current could be passed through the meter. So I can see why a gas co. would not want that.

What is the gas line bonding scheme in your area?

 

[dave*99]

Thanks to all for the replies and general discussion, all insightful.

While I don't have any CSST I'd still like to tie in the gas piping. Since the WH and furnace are co-located and WH is already bonded directly to the panel could the furnace (gas piping in general) be bonded by clamping the black and copper together via two foot of 4ga? Didn't see code that required home-runs for each. Now that I think of it -- A more logical option would be to complete a home-run bond of the black pipe using the stranded ground wire that'll be coming off the soon to be removed copper. This is assuming the existing single 4ga to the ground rod is sufficient otherwise I'd run the stranded outside and rod it. Still would be interesting to know the answer to the struck question above.

I see 75gmck25 mentioned they daisy-chained ground rods. From what I understand doing that still qualifies as a single ground. Would the daisy be needed because the soil resistance provides below the 25-ohm requirement with a single rod?

After further code delving I see my question about using the metal I-beam/post as ground would be a no-go. Seems the concrete would require 20+ foot of dedicated acceptable electrode encasement.

The issues you are addressing may parallel what I faced in my old house. House built in 1965. Iron pipe gas service to the house. Flexible appliance connector gas pipes made final connection to the appliances. The original gas service was not bonded to the electrical system.

During an extensive remodel, CSST was installed. A bond wire was added at the point where the iron gas pipe entered the house. In that house the bond wire was connected to the ground rods in the same spot the main panel was connected to the ground rods. The CSST manifold was a few feet downstream of the iron pipe. That completed the gas system bonding.

IMHO, if you bond the gas system to the service panel bus at the customers piping where it enters the house, and you have 2 ground rods connected to the service panel....... you would meet the requirements for NJ. But of course YMMV.

The gas line bonding was added because installing CSST prompts the requirement to bond the gas system. In 1965 CSST didn't exist and the gas system was not bonded. The plumbing inspector is required to look for that updated bonding when he sees CSST added.

Today, gas system bonding is required.

 

[mm08822]

I don't know know what to tell you other than that is what is enforced here. How is it any different than using EMT as the ground?

Washington Gas is the natural gas distributor in this area. Their contractor installation guide has this interesting requirement in it:


OP - wish you the best. I'm out.

I would assume the utility owned equipment is the meter and upstream of it. That is regulated by utility co/utility regs.

Loadside of the meter (owner provided/responsibility) is not addressed in the green highlighted text. Then is then under the scope of the adopted NEC or other codes. Hence, it needs to be bonded post-meter.

 

[duneslider]

I think it is important to remember that not all flexible pipe is CSST. Most of those flexible lines to stoves, furnaces, and water heaters are NOT CSST. Flexible Appliance Connectors (FAC) are not CSST. FAC doesn't require bonding.

 

[larry4406]

You know your turf better than I, but let me respectfully ask this question:

In my area, the gas piping system is bonded after the meter. The gas service comes through the regulator, meter and connects to the customers piping. The bonding is done on the customers piping at that point. It doesn't matter if you have iron pipe or CSST. That is the bond point and it serves the entire gas system. The bond is not connected to the gas utility equipment.

Our underground gas lines are plastic. If I were to bond to the meter instead of the customer piping, current could be passed through the meter. So I can see why a gas co. would not want that.

What is the gas line bonding scheme in your area?

In my area - For black pipe gas systems, we do absolutely nothing, zero, nada, zilch for bonding. The AHJ's consider that your furnace, your 90+ WH, your Rinnai tankless WH, your gas fireplace, your cooktop, whatever are already grounded via the internal ground of the appliance, its wiring thereof, and the gas piping is threaded to the metallic items of the appliance, so it is thus bonded as well. I have not taken a meter to check continuity between frame of said appliance and gas line to confirm but suspect it will.

It has been so long since we have used CSST, I honestly could not tell you what they require here. I personally would not use that stuff period. Trim nails blow right thru it, and I have had my share of chasing leaks (nail plates don't work when a gas line is dangling in stud bay and one installs trim after paint and shoots blindly into a wall not knowing where the stud is).

I only posted this as the OP indicated he was in MD where I built homes for near 8 years before coming back to VA about 4 years ago.

Good luck OP.

 

[gaalcom]

Sorry for the thread bump, been away from comp for a bit. Just wanted to thank everyone for their insights and opinions.

 

[wyliesdiesels]

Im guessing the reason we connect all gas appliances with flex lines here in cali is due to earthquakes

 

[sparky 1971]

We don't do anything to gas piping unless it has CSST in it but flexible connection lines for dryers, ranges, etc. don't make a bond required if the rest of it is in black iron. I'm not sure if not all flexible gas tubing is CSST or not all CSST needs to be bonded, but the brand Counter Strike, which is the black flexible line, doesn't need to be bonded according to the manufacturer. There is one mechanical inspector that wants it bonded regardless so I just tell the mechanical contractor that since it's not my inspection that has or is going to fail, to run a #6 bare to the water meter and clamp it on both ends. If he doesn't like it, he should have used black iron pipe or he can pay me to do it for him. If it's a copper supply, we also only bond the water within 5' of the meter and jump to both sides of it. Nothing for the hot or anywhere else. When I was in Dallas in the mid 90's, we bonded to the cold pipe at the water heater, but there were no water meters in the house.

 

[wyliesdiesels]

flexible gas lines that we use here are NOT CSST. different animals

 

[sparky 1971]

flexible gas lines that we use here are NOT CSST. different animals

We use flexible connection lines that aren't CSST to connect to dryers and ranges, but if the other end is connected to black iron or Counter Strike, we don't have to bond.

If it's iron pipe, water heaters and furnaces are hard piped.