Why do feeder tap rules specify a minimum size for the tap conductor?

• A. To ensure adequate protection against overloads and short-circuit conditions
• B. To optimize for voltage drop
• C. To reduce installation cost
• D. To comply with labeling requirements

Answer: (A)

Feeder tap rules specify a minimum tap-conductor size to ensure the conductor can safely carry the current that could flow through it during normal operation and, more importantly, during overloads or faults until the protective device trips. If the tap conductor were too small, heat from overload or a fault could cause insulation damage or fire before the protection clears the fault. The minimum size gives enough ampacity to handle the worst‑case current the tap might experience, maintaining safety and reliability.

Voltage drop, installation cost, and labeling requirements are not the primary purpose of this minimum size. Voltage drop is addressed by different sizing considerations, cost is affected by conductor choice but isn’t the safety driver here, and labeling isn’t tied to the conductor’s ability to carry current.