Siemens B240 40A 2P 120 240V 10K BL10 KAIC Bolt On Circuit Breaker

Siemens B240 is a 40‑amp, two‑pole bolt‑on molded‑case circuit breaker (type BL) engineered for 120/240 VAC service, delivering a 10 kA interrupting rating (10 kAIC) to protect multi‑wire branch circuits in commercial panelboards and larger residential installations. Designed for bolt‑on installation with a common‑trip two‑pole configuration, the B240 fits Siemens BL‑series panelboards and is HACR‑rated for HVAC equipment circuits, providing reliable overcurrent protection for feeders and downstream loads with compatibility to standard BL components. This UL 489‑listed unit carries a 10 kAIC rating at 240 V and is part of Siemens' BL bolt‑on lineup, a common choice when replacing or upgrading panelboard protection in systems that require solid, code‑compliant performance. Typically about 2 in wide, 3 in deep, and 3-9/16 in to 4 in tall, this form factor ensures straightforward mounting and alignment in compatible enclosures.