Siemens FXD63B070 Molded Case Circuit Breaker

The "B" in the FXD63B070 catalog number indicates that the breaker is supplied without lugs. The standard FXD63070 includes factory-installed lugs. Because this unit is supplied without lugs, you must source the appropriate line and load lug kits separately.

For 70A to 250A FD Frame breakers like the FXD63B070, you can use the TA1FD350A aluminum lug kit, which accepts 6 AWG to 350 kcmil copper or aluminum wire. If copper lugs are required, use the TC1FD350 kit, which accepts 6 AWG to 350 kcmil copper wire.

This FD Frame molded case circuit breaker is designed for use in Siemens Sentron Type P1, P2, and P3 panelboards, as well as compatible Siemens switchboards and standalone enclosures.

Yes, the FXD63B070 is a direct replacement for older Siemens and ITE FD63B070 circuit breakers. It shares the same physical dimensions and mounting footprint for seamless integration into existing Sentron panels.

The thermal (Long-Time) trip element is fixed at 70 amps for overload protection. However, the magnetic (Instantaneous) trip element is adjustable, allowing you to fine-tune the short-circuit response for your specific application.

This is a unit mount, bolt-on circuit breaker. It bolts directly to the bus or mounting pan in compatible Sentron panelboards and switchboards, providing a secure and reliable mechanical connection.

Always de-energize the panelboard or switchboard before installation. Verify that the system voltage and available fault current do not exceed the breaker's maximum ratings, such as 35kAIC at 480VAC or 22kAIC at 600VAC. Ensure the adjustable magnetic trip is set according to your system coordination study.