Siemens Q21550CT2 NN Quad Pole Circuit Breaker

Siemens Q21550CT2 QT quadplex circuit breaker is a 120/240 V AC plug‑in unit that combines two 15 A single‑pole circuits with a 50 A two‑pole circuit in a four‑pole assembly. Built on the QT frame, it uses a 1/2 in. per‑pole width and is designed for Siemens panels that accept CTL QT breakers, offering a compact solution for multi‑branch protection. The device provides common‑trip protection for the 50 A two‑pole section and carries a 10 kA interrupt rating at 240 V, making it suitable for residential distribution and light‑commercial panel configurations. Install in load centers that specify QT quadplex breakers (Q21550CT2) for coordinated disconnection of all four poles in a single device.