Mounts into older Square D NA1B panelboards to provide robust thermal-magnetic protection for commercial and industrial facilities. This 100A, 2-pole molded case circuit breaker is engineered for 240VAC systems and features long-time and instantaneous trip functions. The bolt-on design ensures a secure connection within compatible legacy load centers. It accommodates 4-1/0 AWG copper or aluminum wiring via standard lug terminals.
What type of panelboard requires the A1B2100 circuit breaker?
This breaker is specifically engineered to mount into legacy Square D NA1B panelboards. It is used to maintain older commercial and industrial distribution systems that require the A1B frame.
Is the A1B2100 rated for direct current applications?
Yes, this breaker carries a 48VDC rating in addition to its standard 240VAC rating, making it suitable for specific low-voltage DC control or distribution circuits.
Is the A1B series still in active production by Square D?
No, the A1B frame is an obsolete commercial breaker line. Replacements are sourced to service existing vintage NA1B panelboards without requiring a complete system retrofit.
How is the A1B2100 secured within the panelboard?
It utilizes a bolt-on connection to attach directly to the busbars of an NA1B panelboard. This provides a secure, vibration-resistant mechanical and electrical connection compared to plug-on designs.
How does the thermal magnetic trip mechanism operate in the A1B2100?
The breaker features fixed Long-Time and Instantaneous (LI) trip functions. A bimetallic thermal element provides delayed tripping for sustained overloads, while an electromagnetic assembly trips the breaker instantly in the event of a short circuit.
Can I use an A1B breaker in place of a Y1B breaker?
No. While they share a similar vintage commercial design, the A1B series is rated for 240VAC systems, whereas the Y1B series was engineered for 277VAC applications. You must match the breaker frame to your system voltage and panelboard type.
What wire sizes are compatible with the A1B2100 lugs?
The factory lugs on this 100A breaker accept copper or aluminum conductors ranging from 4 AWG to 1/0 AWG. Ensure proper torque specifications are followed during installation to prevent terminal overheating.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 2 reviews.
Square D A1B115 - 15A 1 Pole Molded Case Circuit Breaker
I recommend this product
Rated 5 out of 5 stars
7/19/21
Great Service, On Time Delivery, Great Price
SuperBreakers is my a dependable source to meet my customer's requirements at a good value and with on time delivery. When you throw in great customer service, you can't beat that combination.
CH
Cobe H.
Reviewing
Square D A1B120 - 20A 1 Pole Molded Case Circuit Breaker
I recommend this product
Rated 5 out of 5 stars
2/11/19
Repeat customer
Although these breakers are refurbished they work great. It beats having to change the whole panel because of one breaker.