Operating within the SENTRON family, this 20A molded case circuit breaker provides reliable long-time and instantaneous trip functions. It is designed for heavy-duty commercial and industrial applications. This unit bolts into Siemens P1, P2, and P3 panelboards. It is officially replaced by the 3VA4120-6ED34-0AA0, which requires a specific mounting kit for installation. With a 65kAIC rating at 480Y/277V, it includes reverse feed capabilities and is HID rated for lighting applications.
What type of panelboards are compatible with the Siemens LGB3B020B?
This bolt-on breaker is engineered specifically for Siemens P1, P2, and P3 commercial panelboards. It is part of the Sentron family and is not compatible with standard plug-on residential load centers.
What are the conductor requirements for wiring the LGB3B020B terminals?
The factory-installed lugs are rated for both copper and aluminum conductors. You can use 14 to 6 AWG wire for copper installations, or 12 to 6 AWG wire for aluminum.
Can the LGB3B020B circuit breaker be installed in direct current circuits?
Yes, in addition to standard AC ratings, this breaker is certified for 125/250V DC applications with a 14kA interrupting capacity. This allows it to be integrated into compatible industrial control loops or battery backup configurations.
Does the LGB3B020B provide sufficient interrupting capacity for commercial 480V systems?
Yes, this molded case circuit breaker offers robust fault protection for commercial distribution, delivering a 65kA interrupting capacity at 480Y/277VAC and up to 100kA at 240VAC.
Can the overcurrent protection limits be adjusted during installation?
No, this unit features fixed thermal and fixed magnetic trip elements. The long-time overload and instantaneous short-circuit thresholds are factory-calibrated for 20 amps and cannot be field-modified.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 1 review.
Siemens LGB3B045B - 45A 3 Pole Molded Case Circuit Breaker
I recommend this product
Rated 5 out of 5 stars
9/27/26
Siemens Breaker
The breaker was exactly what I needed, and it came within a couple days. The price was in line of what it should’ve been. This was my third purchase from Super Breakers. I will definitely use them again in the future.