Water Meter Grounding & Bonding Requirements - NEC Section 250-68(C)(1)

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mtnelect

mtnelect

HVAC & Electrical Contractor
Location
Southern California
Occupation
Contractor, C10 & C20 - Semi Retired
This concerns a 100 amp electrical service replacement for an older home were the electrical service is in the back yard and the water service is in the front yard. The inspector from a new city wants us to run 60 feet of #6 copper to the water service. We have received an exemption from this requirement from other local jurisdictions in the past. We have filed an appeal with the city, based on the opinion that the higher impedance of the longer run would cause a delay in clearing a fault.

The 2011 NEC has changed the wording from the 2008 NEC, it now appears that connecting to a metal underground water piping system, being used as a grounding electrode is not required to be made within 1.52 m (5 feet) of the point where the underground metal water pipe enters the building. In the 2008 NEC the last sentence stated "shall not be used" which required an exemption in the case of industrial, commercial, and institutional buildings and structures. Another modification was a deletion of the words "grounding electrode system" from the last sentence of 250.52(A)(1) which now means 250.68(C)(1) only applies in the case of an interconnection to other grounding electrodes and even then the wording was changed to "shall be permitted". The main paragraph of 250.68(C) applies to both grounding electrode conductor connections as well as bonding connections to other grounding electrodes, but even then the paragraph used the words "shall be permitted" rather than "shall not be used" which were the words used from the 2008 NEC.
 
mtnelect said:
This concerns a 100 amp electrical service replacement for an older home were the electrical service is in the back yard and the water service is in the front yard. The inspector from a new city wants us to run 60 feet of #6 copper to the water service. We have received an exemption from this requirement from other local jurisdictions in the past. We have filed an appeal with the city, based on the opinion that the higher impedance of the longer run would cause a delay in clearing a fault.
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Ugh!:happysad: A GES has nothing to do with clearing a fault.

250.4(A) Grounded Systems.
(1) Electrical System Grounding. Electrical systems that
are grounded shall be connected to earth in a manner that
will limit the voltage imposed by lightning, line surges, or
unintentional contact with higher-voltage lines and that will
stabilize the voltage to earth during normal operation.
 
If the water pipe qualifies as an electrode it must be part of the GES and connected within 5' of it's entry into the building. I don't see you having much to argue about. As Jumper stated the connection to the electrode has nothing to do with clearing faults so you have no argument with relation to the length of the GEC.
 
mtnelect said:
...

The 2011 NEC has changed the wording from the 2008 NEC, it now appears that connecting to a metal underground water piping system, being used as a grounding electrode is not required to be made within 1.52 m (5 feet) of the point where the underground metal water pipe enters the building. In the 2008 NEC the last sentence stated "shall not be used" which required an exemption in the case of industrial, commercial, and institutional buildings and structures. Another modification was a deletion of the words "grounding electrode system" from the last sentence of 250.52(A)(1) which now means 250.68(C)(1) only applies in the case of an interconnection to other grounding electrodes and even then the wording was changed to "shall be permitted". The main paragraph of 250.68(C) applies to both grounding electrode conductor connections as well as bonding connections to other grounding electrodes, but even then the paragraph used the words "shall be permitted" rather than "shall not be used" which were the words used from the 2008 NEC.
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There is no real code change on this issue between the 2008 and 2011 codes. They just moved the grounding electrode conductor connection requirements out of 250.52 and put them in 250.68. Those rules never should have been in 250.52, as that section is titled "grounding electrodes".
 
Appeal Denied

Appeal Denied

I will be putting on my coveralls ! The local city has denied my appeal, on having to ground the water meter main. That will be over 60 feet of #6 armored cable, from the back of the house to the front of the house.
 
I would use #6 Cu stranded and staple it to the structure. For a 100 amp service if you use cable armor you only probably need a #8 Cu according to 250.66.
 
If it is 100 amp service you may even be able to use 8 AWG instead of 6 AWG. 250.66 is based on size of service entrance conductors. If you use smallest conductor possible to supply the 100 amp service you will end up in the row that allows 8 AWG, if you run an oversized conductor for any reason, you could end up in any row of the table.

as mentioned the grounding electrode/ GEC is not installed for purposes of fault clearing, if it were there would be no need for both 250.66 and 250.122.
 
Water Meter Grounding & Bonding - A Thing of the Past !

Water Meter Grounding & Bonding - A Thing of the Past !

As more and more water utility company's use plastic for laterals, water line bonding will become less important. In my area all the local water utility company's are now using plastic, and the local city that is requiring me to bond, started to change over to plastic laterals, but hand leaking problems. So they went back to copper ! Just my luck !! ...

I had the water supervisor go out to the location to find out if the water lateral was plastic. He found it to be copper, but he stated that 50 % of his city is plastic already.

He also stated that the water services that use copper, have a problem of "Sparking" when they try to remove the meter; he is concerned for his men's safety. I told him that the city should require a bonding jumper on all there meters.
 
mtnelect said:
As more and more water utility company's use plastic for laterals, water line bonding will become less important. In my area all the local water utility company's are now using plastic, and the local city that is requiring me to bond, started to change over to plastic laterals, but hand leaking problems. So they went back to copper ! Just my luck !! ...

I had the water supervisor go out to the location to find out if the water lateral was plastic. He found it to be copper, but he stated that 50 % of his city is plastic already.

He also stated that the water services that use copper, have a problem of "Sparking" when they try to remove the meter; he is concerned for his men's safety. I told him that the city should require a bonding jumper on all there meters.
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Thing of the past for new construction, well at least 99% of the time, but you still have existing water services that are metallic to deal with sometimes.
 
Driving Ground Rods - Easy or Hard ?

Driving Ground Rods - Easy or Hard ?

I can't count how many sledge hammer handles I have broken, driving ground rods. In La Crescenta California, which is called "Rock Crescenta" as it's "Official Name", it's the hardest part of installing a new service. Fortunately, we do more HVAC work. Somehow running 60 feet of #6 armored grounding cable from the back of the house, to the front of the house, seems useless !

You now have code requirements, requiring driving two ground rods to meet the 25 ohm threshold. OK, we did that, now we need to run more grounding to the water meter !

There is more ... Looking at the correction notice:

1. Not enough identification of the neutral at service head.
a. I put three raps of white tape on the neutral ... should have put six
2. Did not bond the water heater inlet water pipe to the gas line.

This new city has required us to do more grounding, than ever before !
 
mtnelect said:
I can't count how many sledge hammer handles I have broken, driving ground rods. In La Crescenta California, which is called "Rock Crescenta" as it's "Official Name", it's the hardest part of installing a new service. Fortunately, we do more HVAC work. Somehow running 60 feet of #6 armored grounding cable from the back of the house, to the front of the house, seems useless !

You now have code requirements, requiring driving two ground rods to meet the 25 ohm threshold. OK, we did that, now we need to run more grounding to the water meter !

There is more ... Looking at the correction notice:

1. Not enough identification of the neutral at service head.
a. I put three raps of white tape on the neutral ... should have put six
2. Did not bond the water heater inlet water pipe to the gas line.

This new city has required us to do more grounding, than ever before !
Click to expand...

Local codes aside, NEC itself doesn't require use of a ground rod, but in most cases it is the easiest/least cost method of providing a grounding electrode when there is no building steel, no qualifying water piping, or no concrete encased electrode. The water pipe does need a supplemental electrode but it doesn't have to be a ground rod(s).

NEC itself doesn't require three, six, etc. wraps of tape for conductor identification. A single wrap is sufficient to meet NEC, you either have a local code requiring more then that or an inspector that doesn't know any better.

Nothing in NEC requires bonding water heater inlet to gas piping. They often may be required to be bonded, but nothing requires a direct jumper between them. Again you could have a local code that requires that.
 
I GOT GROUNDED & BONDED !

I GOT GROUNDED & BONDED !

This new city taught me a lesson ... Check with the local jurisdiction before starting a project. I grounded and bonded everything in this house ... except the kitchen sink !!
 
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