Molded & Insulated Case Circuit Breakers

While our website showcases a large assortment of our products, it does not reflect the complete inventory of products currently available. For real-time availability and to ensure we can meet your specific needs, please contact our sales team at 1-800-328-1842. New products arrive daily and our knowledgeable staff are happy to assist you in locating the exact item(s) you need.

QO270 Square D Circuit Breaker

Square D QO270 circuit breaker; 70 amp, 240 volt, two pole, used electrically OK.
SKU: QO270
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QO280 Square D Circuit Breaker

Square D QO280 circuit breaker; 80 amp, 240 volt, two pole, used electrically OK.
SKU: QO280
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QO290 Square D Circuit Breaker

Square D QO290 circuit breaker; 90 amp, 240 volt, two pole, used electrically OK.
SKU: QO290
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QO3100 Square D Circuit Breaker

Square D QO3100 circuit breaker; 100 amp, 240 volt, three pole, used electrically OK.
SKU: QO3100
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QO315 Square D Circuit Breaker

Square D QO315 circuit breaker; 15 amp, 240 volt, three pole, used electrically OK.
SKU: QO315
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QO320 Square D Circuit Breaker

Square D QO320 circuit breaker; 20 amp, 240 volt, three pole, used electrically OK.
SKU: QO320
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QO325 Square D Circuit Breaker

Square D QO325 circuit breaker; 25 amp, 240 volt, three pole, used electrically OK.
SKU: QO325
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QO330 Square D Circuit Breaker

Square D QO330 circuit breaker; 30 amp, 240 volt, three pole, used electrically OK.
SKU: QO330
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QO335 Square D Circuit Breaker

Square D QO335 circuit breaker; 35 amp, 240 volt, three pole, used electrically OK.
SKU: QO335
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QO340 Square D Circuit Breaker

Square D QO340 circuit breaker; 40 amp, 240 volt, three pole, used electrically OK.
SKU: QO340
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QO345 Square D Circuit Breaker

Square D QO345 circuit breaker; 45 amp, 240 volt, three pole, used electrically OK.
SKU: QO345
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QO350 Square D Circuit Breaker

Square D QO350 circuit breaker; 50 amp, 240 volt, three pole, used electrically OK.
SKU: QO350
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QO360 Square D Circuit Breaker

Square D QO360 circuit breaker; 60 amp, 240 volt, three pole, used electrically OK.
SKU: QO360
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QO370 Square D Circuit Breaker

Square D QO370 circuit breaker; 70 amp, 240 volt, three pole, used electrically OK.
SKU: QO370
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QO380 Square D Circuit Breaker

Square D QO380 circuit breaker; 80 amp, 240 volt, three pole, used electrically OK.
SKU: QO380
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QO390 Square D Circuit Breaker

Square D QO390 circuit breaker; 90 amp, 240 volt, three pole, used electrically OK.
SKU: QO390
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QOB115 Square D Circuit Breaker

Square D QOB115 circuit breaker; 15 amp, 240 volt, one pole, used electrically OK.
SKU: QOB115
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QOB120 Square D Circuit Breaker

Square D QOB120 circuit breaker; 20 amp, 240 volt, one pole, used electrically OK.
SKU: QOB120
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QOB130 Square D Circuit Breaker

Square D QOB130 circuit breaker; 30 amp, 240 volt, one pole, used electrically OK.
SKU: QOB130
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QOB140 Square D Circuit Breaker

Square D QOB140 circuit breaker; 40 amp, 240 volt, one pole, used electrically OK.
SKU: QOB140
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New, Used, and Tested Molded & Insulated Case Circuit Breakers

EMSCO has been specializing in used and refurbished molded & insulated case circuit breakers for over 72 years.


Why Choose EMSCO for Molded Case or Insulated Case Circuit Breakers?

Want to match and replace your existing breakers? End the hassle of retrofitting your electrical system. Our extensive inventory includes a variety of Molded Case Circuit Breakers (MCCBs) and Insulated Case Circuit Breakers that are designed to seamlessly match and replace your existing breakers by brand, amp rating, voltage, frame size, or model.

New and Refurbished Products in Stock

We understand that budgets and preferences differ, so we give you the option of selecting between new and refurbished MCCBs or Insulated Case Breakers, both of which are readily available in our inventory. Choose brand-new circuit breakers for maximum performance and longevity, or look into our refurbished options, which have been rigorously tested and reconditioned to meet industry standards.

Popular Brands and Common Configurations

Our shelves are stocked with breakers from the most trusted and popular brands in the industry, ensuring you have access to dependable products. You'll find common configurations, such as different frame sizes and voltage ratings, making it simple to find the right circuit protection for your application.

Avoiding Costly Operational Downtime

Downtime can be an expensive situation. Our circuit protection products are designed for high performance and durability. You can avoid costly operational downtime due to electrical failures by using our fully-tested Molded Case or Insulated Case breakers. Our products provide reliable power and superior equipment protection.

Electrical Testing Equipment Certifying Quality and Performance

When it comes to the dependability and safety of your electrical systems, we leave nothing to chance. Our breakers are rigorously tested using current testing equipment to ensure that they meet or exceed industry standards. This ensures that your electrical installations are safe and efficient.

  • Overcurrent Protection: We verify that your breakers provide accurate overcurrent protection, guaranteeing the safety of your electrical systems.
  • Trip Time: We measure the time it takes for breakers to respond to overcurrent conditions, ensuring it operates within the specified trip time.
  • Short-Circuit Withstand Capacity: Our testing evaluates the breaker’s ability to withstand short-circuit currents, preventing damage and maintaining safety.
  • Interrupting Capacity: We determine the MCCB's capability to interrupt fault currents, ensuring the utmost protection for your electrical system.

Molded Case Circuit Breaker Specifications

A sample table of ampere ratings, corresponding voltage ratings, and frame sizes for molded case circuit breakers is shown below. Please keep in mind that frame sizes and ratings can differ between manufacturers and models. For precise details on a specific MCCB, always refer to the manufacturer's specifications.

Frame Size

Ampere Rating

Voltage Rating

A

15A

120V, 240V

A

20A

120V, 240V

B

30A

120V, 240V, 480V

B50A120V, 240V, 480V
C60A240V, 480V
C100A240V, 480V
D150A240V, 480V, 600V
D200A240V, 480V, 600V
E250A240V, 480V, 600V
E300A240V, 480V, 600V
F400A240V, 480V, 600V
F600A240V, 480V, 600V
G800A240V, 480V, 600V
G1200A240V, 480V, 600V
H1600A240V, 480V, 600V

This table is a sample representation of frame sizes, ampere ratings, and voltage ratings for Molded Case Circuit Breakers, not an exhaustive list.

Molded case circuit breakers (MCCBs) and insulated case circuit breakers (ICCBs) are two distinct types of circuit protection devices used in electrical systems. Both serve the purpose of interrupting electrical currents in case of faults or overloads, but they differ in construction, application, and performance characteristics. Need Help Now? Call 800-328-1842.