mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Came across this video recently about why the GEC to building steal is so big:
While I agree, I just want to compliment it by adding two more reasons:
1) IMO one major reason behind bonding pipes and building steal is to prevent them from becoming energized should a hot wire touch them. This must take into account the largest feeder likely to be originating out of the MDP. The GEC must be large enough that the feeder breaker is cleared without overheating the GEC beyond its thermal withstand. A ground rod on the other hand is not in place to prevent anything from becoming energized.
2) Because building steal will often be contact with city piping, it is possible for the GEC is carry (significant) parallel neutral current and must do so without overheating. A lower Z is present back to the X0 than a ground electrode.
What do others think?
While I agree, I just want to compliment it by adding two more reasons:
1) IMO one major reason behind bonding pipes and building steal is to prevent them from becoming energized should a hot wire touch them. This must take into account the largest feeder likely to be originating out of the MDP. The GEC must be large enough that the feeder breaker is cleared without overheating the GEC beyond its thermal withstand. A ground rod on the other hand is not in place to prevent anything from becoming energized.
2) Because building steal will often be contact with city piping, it is possible for the GEC is carry (significant) parallel neutral current and must do so without overheating. A lower Z is present back to the X0 than a ground electrode.
What do others think?