Circuit Breakers - Molded Case, I-Line &Bolt-On, 15A to 3000A
1840 circuit breakers in stock from Square D, Eaton Cutler-Hammer, GE, Siemens, and legacy Westinghouse — new, factory surplus, and bench-tested reconditioned units. Every breaker is inspected against its published trip curve and warrantied for one year. Filter by amp rating, poles, voltage, or condition, or send us a part number to cross-reference.
Molded cases 986 I-Line 322 BOLT ON 348 Plug-in 184 Obsolete & discontinued 412 electronic trip 286
How to Choose The Right Circuit Breaker
A replacement breaker has to match 4 things before price matters; the frame, the amp rating, the number of poles, and the interrupting ratings. Get the frame wrong and it will not physically seat the panel; get interrupting rating wrong and it will not clear a fault safely, regardless what the amp rating says.
Frame Type
Molded case breakers cover most industrial branch and feeder applications. I-Line units plug into Square D panelboards and are keyed by frame, so an FA cannot substitute for a KA. Bolt-on breakers mount directly to the bus and are common in older panels - check the mounting centers before ordering.
Amp rating and trip unit
Match the amp rating to the conductor ampacity and the load, not to whatever was in the panel - previous owners upsize breakers more often than you would hope. Thermal-magnetic trip units suit fixed loads; electronic trip units let you adjust the long-time and instantaneous pickup on motor and feeder circuits.
Interrupting rating (KAIC)
The available fault current at the panel sets the minimum KAIC. If your coordination study says 22 kA, a 10 kA breaker is not a cheaper option - it is a code violation. When in doubt, send us the study or the panel schedule and we will confirm before shipping.
New, surplus, or reconditioned?
For discontinued frames, factory-surplus and reconditioned units are frequently the only option - and often the better one, since a tested reconditioned breaker beats a questionable substitution. Ours are cleaned, inspected, and electrically tested to the published trip curve, then warrantied for a year. Read our reconditioning process.
Yes - obsolete and discontinued frames are a core part of our inventory, including legacy Square D, Westinghouse, Federal Pacific, and GE lines that have been out of production for decades.
Every reconditioned unit is disassembled, cleaned, inspected, and electrically tested to its published trip curve before it ships, then covered by the same one-year warranty as new stock.
No. Frames are keyed to the panelboard, so an FA will not seat where a KA belongs even at the same amp rating. Send us the panel schedule and we will confirm the correct frame.
The available fault current at the panel sets the minimum KAIC - usually from your coordination study. If you do not have one, send the transformer size and conductor run and we will help estimate it.
The available fault current at the panel sets the minimum KAIC - usually from your coordination study. If you do not have one, send the transformer size and conductor run and we will help estimate it.
In-stock breakers ordered before 3PM ET ship the same business day, with overnight and counter-to-counter freight available for line-down emergencies.
Popular part numbers
FAL3402 FAL3610 KAL36250
THQL2120 QOB320 ED43B100
BREAKERS BY BRAND
Square D circuit breakers
Eaton Cutler-Hammer breakers
GE Spectra & THQL breakers
Siemens breakers
Westinghouse (legacy)
BREAKERS BY AMP RATING
20A circuit breakers
100A circuit breakers
400A molded case breakers
800A I-Line breakers 1200A main breakers
1200A main breaker
RELATED CATEGORIES
Motor starters
Safety switches & disconnects
Fuses & fuse blocks
Panelboards & enclosures
Obsolete & discontinued parts