Part of the legacy ET100 series, this 90A molded case circuit breaker provides essential thermal-magnetic protection for older commercial and industrial setups. Rated for 600VAC and 250VDC, it delivers a 14kAIC interrupting capacity at 480V. The breaker installs into classic ITE and Siemens F-frame panelboards and switchboards, serving as an exact cross-reference for the FXD63B090 and F3B090. It includes line and load lugs for immediate integration into existing bolt-on configurations.
Common Trip, Trip-Free Mechanism, Quick-Make/Quick-Break, HACR Rated
Product FAQs
6 answers
What panelboards are compatible with the ET100-390 circuit breaker?
This legacy F-Frame breaker is designed to bolt directly into classic ITE and Siemens F-Frame panelboards and switchboards.
Which Siemens catalog numbers does the ET100-390 replace?
The ET100-390 serves as an exact cross-reference and replacement for the Siemens FXD63B090 and F3B090 90-amp molded case circuit breakers.
Do I need to purchase separate lugs for the ET100-390?
No, the breaker comes with factory-installed lugs that accept copper or aluminum (Cu/Al) wire from 4 AWG to 1/0 AWG.
Can I adjust the trip curve on the ET100-390?
No, this breaker features a fixed thermal and fixed magnetic trip unit. The long-time and instantaneous (LI) trip points cannot be adjusted in the field.
Is the ET100-390 rated for direct current (DC) systems?
Yes, this breaker is certified for DC applications up to 250VDC, providing a 10kA interrupting capacity for those specific setups.
Does the ET100-390 provide ground fault or equipment protection?
No, this is a standard thermal-magnetic breaker that provides basic overload and short-circuit protection. It does not include GFCI, AFCI, or equipment protection (EPD) features.
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