Redundant neutral?

kjroller

Senior Member
Location
Dawson Mn
Occupation
Master electrician
Question, why dont you need a grounding or redundant grounded conductor with your Triplex coming into your service wouldnt be helpful to have a redundant ground wire back to the utility incase the main service neutral ever came lose so it doesnt send 120 volts to metal down the line from it? I feel it would act as a redudant path back to source. Please let me know if my thinking is wrong. Wouldnt it eliminate the chance of this dangerous situation depicted below from happening
 

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Utility systems are often multi-grounded neutral (MGN) or TN-C systems (C= Combined) , where the grounded conductor, which may be a neutral, and the supply-side bonding function are combined in a single conductor. That conductor carries load current and also serves as the ground-fault return path. In Articles 230, 240, and 250, the NEC uses terms such as "service conductors" to describe what is often, in practice, an (unfused) TN-C system.

After the first means of disconnect, these functions are Separated into the grounded conductor and the equipment grounding conductor.

In theory, other kinds of services are possible, such as IT or TN-S (S=Separate) . What you are describing may be closer to a TN-S arrangement, or to a separately derived system. However, there is still only one point at which the grounded conductor is connected to the grounding electrode system (GES).
 
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