Where fuses are used as the service overcurrent device, the disconnecting means shall be located ahead of the load side of the fuses in accordance with 230.91.

• A. True
• B. False
• C. Depends on voltage
• D. Not specified

Answer: (B)

The rule being tested is about where the service disconnect must be located when fuses are used as the service overcurrent device. When fuses serve as the service OCPD, the disconnecting means must be placed on the line side of those fuses so it can isolate the service from the source before the fuse block. Putting the disconnect on the load side (after the fuses) would not provide a complete, upstream isolation of the service and would not meet 230.91.

Voltage level doesn’t change this placement; it’s about ensuring a readily accessible means to disconnect all supply conductors ahead of the fuse protection. Practically, you’d expect the disconnect to be mounted between the utility/service entrance and the fuse block, not downstream of the fuses.