A disconnecting means is rated 100 amperes. No circuit configuration is specified. What can be concluded about the required number of switched poles?
- AIt must have one pole
- BIt must have two poles
- CIt must have three poles
- Its ampere rating alone is insufficient to determine the pole count
Where to look it up
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.304
Why D is correct
Pole selection depends on the circuit configuration and the conductors that must be disconnected, not on ampere rating alone. Do not add a switched pole for the equipment grounding path, which must remain continuous and effective. Any neutral-switching requirements need a separate assessment; neutral and equipment grounding conductors have different functions.