Required neutral to service disconnect

[Jpflex]

Nec 250.24 D says that if an ac system operating at 1000 volts or less is grounded at ANY point, the grounded conductors shall be routed with the ungrounded conductors to each service disconnecting means and connected to disconnecting means grounded conductors or bus...

If the utility servuce supplying the premises wiring is grounded the grounded conductor must be run to service equipment regardless if line to neutral loads are supplied.


In contradiction

Nec 250.184 B 6 says for a single point grounded neutral system:

A neutral conductor shall only be required if phase to neutral loads are supplied

Is this latter section a modification to the previous code, or referring to dc? Or why this contradiction?

 

[wwhitney]

In contradiction

Nec 250.184 B 6 says for a single point grounded neutral system:

No contradiction: What Part of Article 250 is 250.184 in? What is the title of that Part? How do those answers compare for 250.24?

Cheers, Wayne

 

[Jpflex]

250.184 is under the article of general grounding and bonding. Title is solidly grounded neutral systems.



Section 250.24 D is also in the same artice for grounding and bonding. The title here is grounding service supplied ac systems



Services have to be supplied with a neutral according to 250.24 D

However, these services can also be classified as a solidly grounded neutral system if no ground impedance input in grounding system and also considered as a single point grounded neutral system where the neutral is grounded at only 1 location such as at the supply side of the service.

With a neutral always being required at a service nec 250.184 B 6 no longer makes sence regardless of if line to neutral liads are served

 

[infinity]

Did you miss this part?

Part X. Grounding of Systems and Circuits of over 1000 Volts

 

[Jpflex]

Did you miss this part?

O maybe