The electrical inspection department in Saskatchewan has now mandated in its 2015 Interpretations that the neutral shall be grounded at the utility connection point and be kept separate from the ground, after.
This is an issue on farms where the ground point will typically be at the meter and one or more buildings fed from that meter. In the past, the neutral would be grounded at each building. Now, a ground will run with the circuit conductors and a ground rod at the building would only be connected to the panel enclosure. Every panel will be installed as a sub panel and the bonding screw must be removed from the neutral bar and the neutral conductor isolated from ground.
Because these buildings are usually fed underground, the conductors can be damaged. It's possible to lose a hot or a neutral. With the new requirement, it will be possible to lose a ground connection, too. A broken ground wire would allow the system to operate normally but the ground at the building would float.
I was taught that if the ground were allowed to float, fate would chose the conductor to be grounded. For example, a receptacle twisted in the box could cause a hot conductor to touch ground. That would bring the remote building ground along with metallic surfaces, like the panel enclosure, to a line voltage potential. Then, the voltage from ground to neutral would be 120 volts and from ground to the other hot would be 240 volts.
Is this now considered a good idea or are we just forgetting lessons from the past?
