If THREE individual, single-pole breakers are handle tied and used for a 3Ø circuit, which statement is true?

If THREE individual, single-pole breakers are handle tied and used for a 3Ø circuit, which statement is true?

• A. II only
• B. I only
• C. Both I and II
• D. Neither I nor II

Answer: (A)

For a three-phase circuit, all ungrounded conductors must be disconnected by a single disconnecting means. Using three individual single-pole breakers with a handle tie does not provide a true common disconnect because there is no common-trip mechanism tying all three poles to trip together in a fault. The handle tie only synchronizes manual operation; it does not guarantee simultaneous automatic disconnection of all phases. So the statement that this arrangement does not provide a proper common disconnect is the correct one. The correct approach is to use a listed three-pole breaker (or another listed common-trip arrangement) so all three phases are guaranteed to disconnect together, ensuring a safe, complete de-energization.

For a three-phase circuit, all ungrounded conductors must be disconnected by a single disconnecting means. Using three individual single-pole breakers with a handle tie does not provide a true common disconnect because there is no common-trip mechanism tying all three poles to trip together in a fault. The handle tie only synchronizes manual operation; it does not guarantee simultaneous automatic disconnection of all phases. So the statement that this arrangement does not provide a proper common disconnect is the correct one. The correct approach is to use a listed three-pole breaker (or another listed common-trip arrangement) so all three phases are guaranteed to disconnect together, ensuring a safe, complete de-energization.