Siemens Q24030CT2 is a quadplex QT-series molded‑case circuit breaker for 120/240 V residential load centers, providing two internally linked 2‑pole sections in a single plug‑in unit to save panel space. It is rated for 120/240 V operation with a 40–30 A amperage range and a 10 kA interrupt rating, using thermal‑magnetic trip to protect circuit integrity. The two poles share a common trip, ensuring both circuits disconnect together, and the device is built to UL 489 standards as part of Siemens' QT quadplex lineup for residential distribution.
