We have been verifying bonds for our CATV system and found issues mostly with apt. buildings. The question is this: If we drive a ground rod in our outside pedestal and bond to the building ground, is there a max length that #6 can run or would we have to use larger gauge? Some of the runs will be 20ft and some 150ft!! I know the idea is to limit potential differences, so is there a way to measure the potential on different conductors and decide on ground size, etc?
Bonding GEC's
- Thread starter Kevlar
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Bonding GEC's
There is no current in a Grounding Electrode Conductor, unless there is a problem somewhere (e.g., high impedance ground fault). Therefore, there will be no voltage drop along that conductor. The GEC is sized on the basis of the size of the phase conductors, not on the basis of its length. You don?t have to ?biggie-size.?
There is no current in a Grounding Electrode Conductor, unless there is a problem somewhere (e.g., high impedance ground fault). Therefore, there will be no voltage drop along that conductor. The GEC is sized on the basis of the size of the phase conductors, not on the basis of its length. You don?t have to ?biggie-size.?
- Location
- Illinois
- Occupation
- retired electrician
Re: Bonding GEC's
Why is excessive length of this bonding conductor a problem only in one and two family dwelling units? Look at 800.40(A)4 and its exception.
Why is excessive length of this bonding conductor a problem only in one and two family dwelling units? Look at 800.40(A)4 and its exception.
Re: Bonding GEC's
The reason apts. are more of a concern is typically they are post wired and pose unique problems. I guess the concern is if some kind of surge happens, our ped with ground rod may only be 20 ft from some units and 100 ft to others. Will bonding the GECs stop damage to equipment etc. Most of our MDUs have service right by the power service so bonding is easy, the concern was with the long bonds.
Thanks for the replys.
The reason apts. are more of a concern is typically they are post wired and pose unique problems. I guess the concern is if some kind of surge happens, our ped with ground rod may only be 20 ft from some units and 100 ft to others. Will bonding the GECs stop damage to equipment etc. Most of our MDUs have service right by the power service so bonding is easy, the concern was with the long bonds.
Thanks for the replys.
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