Square D LA26400BC Molded Case Circuit Breaker

The "BC" suffix indicates the phase connection for the I-Line plug-in mounting. It means this 2-pole breaker connects specifically to the B and C phases on the panelboard busbar.

No. The LA26400BC features an I-Line style plug-in connection designed exclusively for Square D I-Line panelboards and switchboards. It cannot be used in standard QO, Homeline, or unit-mount applications.

All three are 400A, 2-pole, 600V I-Line circuit breakers. The difference is the phase connection on the busbar: AB connects to phases A and B, AC connects to phases A and C, and BC connects to phases B and C. You must select the correct suffix based on your panelboard phase balancing requirements.

Yes, the standard lugs on this breaker can accept either a single conductor from 1 AWG to 600 kcmil or dual conductors from 1 AWG to 250 kcmil (aluminum or copper) per phase.

The thermal trip (Long-Time) is fixed at 400A, but the magnetic trip (Instantaneous) is adjustable. This allows you to fine-tune the short-circuit protection threshold to coordinate with other devices in your electrical system.

The "LI" designation means the thermal-magnetic trip unit provides Long-Time (L) and Instantaneous (I) protection. The Long-Time function protects against sustained overloads, while the Instantaneous function protects against sudden short circuits.

Yes. Even though it is a 2-pole breaker, it is designed to plug into a standard 3-phase Square D I-Line panelboard. The "BC" suffix ensures it connects specifically to the B and C phases of the busbar.

No. As an I-Line style plug-in breaker, it features built-in mounting jaws that attach directly to the panelboard busbar. A retaining bracket is typically included with the panelboard interior, but the breaker itself does not require a separate mounting kit.