Engineered for commercial applications, the Siemens EF3B020 is a 3-pole, 20A molded case circuit breaker from the legacy EF frame family. It provides dependable thermal-magnetic trip protection for up to 600VAC systems. This bolt-on unit installs into older Siemens, I-T-E, and FC-1 panelboards, as well as FC-20 switchboards. It is replaced by the modern ED63B020 for system upgrades. Rated at 14kAIC at 480V and 18kAIC at 240V, it features a non-interchangeable trip and is HACR rated.
Which panelboards are compatible with the Siemens EF3B020 circuit breaker?
The EF3B020 is a bolt-on molded case circuit breaker designed for use in legacy Siemens and I-T-E distribution equipment, specifically FC-1 panelboards and FC-20 switchboards.
Is the Siemens EF3B020 a legacy breaker, and what is the modern replacement?
Yes, the EF3B020 is part of the legacy Siemens and I-T-E E-Frame series. For modern panel upgrades or direct replacements, the Siemens ED63B020 serves as the current factory equivalent.
What wire sizes are approved for the load side lugs on the EF3B020?
The included load side lugs accept 14 to 10 AWG copper (Cu) conductors or 12 to 10 AWG aluminum (Al) conductors. Always verify that the wire bending space in your enclosure accommodates these sizes before installation.
Can the EF3B020 be utilized in DC power systems?
Yes, this thermal magnetic breaker is rated for DC applications up to 250VDC, providing an interrupting capacity of 10kA at 250VDC.
How does the EF3B020 mount into the electrical panel?
This is a bolt-on circuit breaker that requires a secure, bolted connection directly to the panelboard busbar. It cannot be used in load centers that require plug-on or snap-in mounting.
Are the trip settings on the EF3B020 adjustable?
No, the EF3B020 features a fixed thermal magnetic trip unit. Both the long-time (thermal) and instantaneous (magnetic) protection functions are factory set and cannot be adjusted in the field.
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Customers rate this product 5.0 out of 5 based on 2 reviews.