I hope this is a simple question that won't stirr up alot of trouble!!!!!! In my town they do not allow grounding to the water pipes. They want 2 rods (1/2 x 8) min. 6 ft. apart. This is for 200 amp 120/240 single phase undergound srv new construction. Is there a better way? How about Ufer grnd system? How about a #2 grnd wire connected to #4 rebar in the footing min. 4ft down around entire building then up thru the concrete wall, then to the 2 grnd rods, then to the meter base? Thanks Gunny
grounding
- Thread starter gunny7
- Start date
- Status
- Location
- Massachusetts
Re: grounding
I'm with Bennie on this.
Install the two rods they want and move on.
What concerns you about this?
I'm with Bennie on this.
Install the two rods they want and move on.
What concerns you about this?
- Location
- Massachusetts
Re: grounding
Just a guess here Tony, but the water company probably installs a dielectric coupling inside the house and the bonding must be done on the house side of that.
Just a guess here Tony, but the water company probably installs a dielectric coupling inside the house and the bonding must be done on the house side of that.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: grounding
Gunny: I see from your post that you are an inspector. Because of the this, you cannot require any more tahn the two rods, unless another electrode is available. The decision to "make one available" is not the inspector's.
Just out of curiosity, why does your town not permit metal water piping as an electrode?
Gunny: I see from your post that you are an inspector. Because of the this, you cannot require any more tahn the two rods, unless another electrode is available. The decision to "make one available" is not the inspector's.
Just out of curiosity, why does your town not permit metal water piping as an electrode?
- Location
- Bremerton, Washington
Re: grounding
Go with the Ufer. No ground rods are required, but can be installed, with the Ufer. See NEC section 250.52.
Or
Drive two and go home.
However, even if you don't use the water pipe as an electrode per 250.52(A)(1), it still has to be bonded per 250.104. The difference is the bonding connection per 250.104 does not have to be within 5 ft of the entrance to the building of the water line.
Go with the Ufer. No ground rods are required, but can be installed, with the Ufer. See NEC section 250.52.
Or
Drive two and go home.
However, even if you don't use the water pipe as an electrode per 250.52(A)(1), it still has to be bonded per 250.104. The difference is the bonding connection per 250.104 does not have to be within 5 ft of the entrance to the building of the water line.
jp_electric
Member
Re: grounding
I don't understand that. How would you even clear a 15-20 amp breaker? if you took the hot wire directly to both of the grounding conductors at 120 volts would probally be under 10 amps getting 25ohms can be hard enough. I know the water company does not like using waterpipe beacause they say the neutral current may cause corrosion
I don't understand that. How would you even clear a 15-20 amp breaker? if you took the hot wire directly to both of the grounding conductors at 120 volts would probally be under 10 amps getting 25ohms can be hard enough. I know the water company does not like using waterpipe beacause they say the neutral current may cause corrosion
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: grounding
JP: Are you implying that the water pipe clears faults?
JP: Are you implying that the water pipe clears faults?
jp_electric
Member
Re: grounding
I belive so. I never stuck 120 to it to find out. but id bet there is a much better chance. with x amount of underground waterpipe bonded to every neiorbors piping and ground rod. yes i believe it would. any experiences?
I belive so. I never stuck 120 to it to find out. but id bet there is a much better chance. with x amount of underground waterpipe bonded to every neiorbors piping and ground rod. yes i believe it would. any experiences?
- Location
- Massachusetts
Re: grounding
JP the grounding electrodes are not for clearing faults of the voltages that are normally in a house.
The fault clearing path for the branch circuits is through the bonding jumper or screw in the service disconnect.
With no grounding electrodes connected faults will still clear.
The grounding electrodes are for lightning and high voltage faults from the utility.
You are right the water pipe many times could clear a fault due to being bonded many times at other services, but this is not what the connection is for and you never know when the water company will replace metal pipes with plastic.
JP the grounding electrodes are not for clearing faults of the voltages that are normally in a house.
The fault clearing path for the branch circuits is through the bonding jumper or screw in the service disconnect.
With no grounding electrodes connected faults will still clear.
The grounding electrodes are for lightning and high voltage faults from the utility.
You are right the water pipe many times could clear a fault due to being bonded many times at other services, but this is not what the connection is for and you never know when the water company will replace metal pipes with plastic.
Re: grounding
"In my town they do not allow grounding to water pipes - - -"
How is tha requirement spelled-out ? 250.50 is very clear what is to be used as grounding electrodes. I do not understand how a water pipe, meeting 250.52(A(1), can be abolished with-out a State or city ordinance with specfic number(s) and dates, spelling-out this requirement can superceed an ordinance or law adopting the NEC ( or a modificAtion of the NEC) in other words, be sure it is a Legal law.
gwz2
"In my town they do not allow grounding to water pipes - - -"
How is tha requirement spelled-out ? 250.50 is very clear what is to be used as grounding electrodes. I do not understand how a water pipe, meeting 250.52(A(1), can be abolished with-out a State or city ordinance with specfic number(s) and dates, spelling-out this requirement can superceed an ordinance or law adopting the NEC ( or a modificAtion of the NEC) in other words, be sure it is a Legal law.
gwz2
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: grounding
are you bonding the water pipe to the ground?
are you bonding the water pipe to the ground?
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Re: grounding
"JP: Are you implying that the water pipe clears faults?"
I say yes.
We are talking about bonding now. Not the electrode.
The reason to "bond" to the waterlines is to clear faults when electric wires comes in contact (dead shorts) with the metal waterlines.
Mike P.
"JP: Are you implying that the water pipe clears faults?"
I say yes.
We are talking about bonding now. Not the electrode.
The reason to "bond" to the waterlines is to clear faults when electric wires comes in contact (dead shorts) with the metal waterlines.
Mike P.
- Location
- Massachusetts
Re: grounding
Mike I agree with you on the bonding, but this post was about grounding and specifically JPs post made reference to ground rods.
The water pipes will clear faults only because we bond them to the grounding conductors which in turn are connected to the neutral.
I think it is important to make clear the earth is not a part of fault clearing for dwelling unit voltages.
Mike I agree with you on the bonding, but this post was about grounding and specifically JPs post made reference to ground rods.
The water pipes will clear faults only because we bond them to the grounding conductors which in turn are connected to the neutral.
I think it is important to make clear the earth is not a part of fault clearing for dwelling unit voltages.
pierre
Senior Member
- Location
- Westchester County, New York
Re: grounding
These posts on clearing faults using/connecting to the cold water pipes is a little confusing, especially for those who may not have a clear understanding of the principle/theory behind it.
Bonding the cold water to the system is not for clearing faults, but to keep the water pipes at the same potential as the system, in case the water pipes should accidently become energized by a fault current. The fault current then would flow back to the source via the bonding path, opening the protective device (breaker or fuse)that is serving that particular circuit that has caused the fault.
Pierre
These posts on clearing faults using/connecting to the cold water pipes is a little confusing, especially for those who may not have a clear understanding of the principle/theory behind it.
Bonding the cold water to the system is not for clearing faults, but to keep the water pipes at the same potential as the system, in case the water pipes should accidently become energized by a fault current. The fault current then would flow back to the source via the bonding path, opening the protective device (breaker or fuse)that is serving that particular circuit that has caused the fault.
Pierre
- Status