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.

Square D MasterPact NW20N Circuit Breaker 2000 Amp 600 Volt AC E/O D/O

Square D MasterPact NW20N Circuit Breaker; cat# WL1FFR33A9SXXXXXXX, 2000 Amp, 600 volt AC, 3 pole. With micrologic 5.0A trip unit, LSI functions, electrically operated (E/O), draw-out (D/O). Used tested with report.
SKU: MCCB2045
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Westinghouse RD65K Circuit Breaker RD320TW 2000 Amp 600 Volt AC M/O F/M

Westinghouse RD65K Series C Circuit Breaker; cat# RD320TW, 2000 amp, 600 volt AC, 3 pole. With Westinghouse RS Seltronic trip unit cat# RS32000T, 1600 amp rating plug cat# 20RS16T, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2046
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Cutler-Hammer/ Westinghouse RD65K Circuit Breaker RD316T56W 1600 Amp 600 Volt AC M/O F/M

Cutler-Hammer/ Westinghouse RD65K Circuit Breaker; cat# RD316T56W, 1600 amp, 600 volt AC, 3 pole. With Digitrip RMS510 trip unit cat# S56LSIG (B), LSIG functions, ground fault, 1600 amp rating plug cat# RP6R16A160, handle lock cat# HLK6, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2047
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Eaton RGH65K Circuit Breaker RGH316038E 1600 Amp 600 Volt AC F/M M/O

Eaton RGH65K Circuit Breaker; cat# RGH3156038E, 1600 amp, 600 volt AC, 3 pole. With RT316038 trip unit, LSI functions, fixed-mount (F/M), manually operated (M/O). Used tested with report.
SKU: MCCB2048
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Square D RJ1600 PowerPact Circuit Breaker RJF36160JK 1600 Amp 600 Volt AC M/O F/M

Square D RJ1600 PowerPact Circuit Breaker; cat# RJF36160JK, 1600 amp, 600 volt AC, 3 pole, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2049
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Square D SEF364000LSGZ Electronic Trip Circuit Breaker 4000 Amp 600 Volt AC M/O F/M

Square D SEF364000LSGZ Electronic Trip Circuit Breaker; 4000 amp, 600 volt AC, 3 pole. With micrologic full function series B trip unit, LSIG functions, ground fault, rating plug cat# ARP100, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2051
$37,500.00

Square D NW12HF MasterPact Automatic Switch 1200 Amp 600 Volt 4 Pole M/O F/M

Square D NW12HF MasterPact Automatic Switch; cat# BL3CCVSSX9CFBFXXCA, 1200 amp, 600 volt AC, 4 pole, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2052
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GE Power Break TC2020TTR Circuit Breaker 2000 Amp 600 Volt AC

General Electric Power Break TC2020TTR Circuit Breaker; 2000 amp, 600 volt AC, 3 pole. With MicroVersaTrip plus trip unit cat# C220LSIG, LSIG functions, ground fault, 2000 amp rating plug cat# TR20B2000. Used tested with report.
SKU: MCCB2053
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GE Power Break TP84SS Breaker 400 Amp 600 Volt AC M/O F/M

General Electric Power Break TP84SS Circuit Breaker 400 amp, 600 volt AC, 3 pole. With RMS-9 MicroVersaTrip trip-unit cat# TS20LSI, LSI functions, 400 amp rating plug cat# TR4S400, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2057
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Square D PEC1236G Circuit Breaker 1200 Amp 600 Volt AC F/M M/O

Square D PEC1236G Circuit Breaker; 1200 amp, 600 volt, 3 pole, ground fault, fixed mount (F/M), manually operated (M/O). Used tested with report.
SKU: MC-CB#2058
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Square D PAF2036 Circuit Breaker 2000 Amp 600 Volt AC M/O F/M

Square D PAF2036 Thermal-Magnetic Circuit Breaker; 2000 amp, 600 volt, 3 pole, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2059
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Square D PAF362000DC1625 Circuit Breaker 2000 Amp 500 Volt DC M/O F/M

Square D PAF362000DC1625 Circuit Breaker; 2000 amp, 500 volt DC, 3 pole. With auxiliary switch, under voltage trip, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2060
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Square D PXF361600G Electronic Trip Circuit Breaker 1600 Amp 600 Volt AC M/O F/M

Square D PXF361600G electronic trip circuit breaker; 1600 amp, 600 volt AC, 3 pole. With micrologic standard series B trip unit, LSIG functions, ground fault, rating plug cat# ARP100, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2061
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Square D PAF361200G Circuit Breaker 1200 Amp 600 Volt AC M/O F/M

Square D PAF361200G circuit breaker; 1200 amp, 600 volt AC, 3 pole. With ground fault shunt trip. manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2062
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Square D SEFG30 Solid State Trip Circuit Breaker 3000 Amp 600 Volt AC M/O F/M

Square D SEFG30 solid state trip circuit breaker; 3000 amp, 600 volt AC, 3 pole. With micro logic trip unit cat# S930LIGA, LIG functions, ground fault, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MC-CB#2063
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Square D MasterPact NW30H Circuit Breaker 3000 Amp 600 Volt AC M/O F/M

Square D MasterPact NW30H Circuit Breaker; cat# WL3HGG43A9SXFXXXXX 3000 amp, 600 volt AC, 3 pole. With 2500 amp rating plug, manually operated (M/O), fixed-mount (F/M). Used tested with report. **No Trip Unit
SKU: MCCB2064
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GE Power Break THPMMF86 Circuit Breaker 3000 Amp 600 Volt AC M/O F/M

General Electric Power Break THPMMF86 Circuit Breaker; 3000 amp, 600 volt AC, 3 pole. With shunt trip- 48 volt DC, auxiliary switch, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2065
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Westinghouse PB32500F Circuit Breaker 2500 Amp 600 Volt AC F/M M/O

Westinghouse PB32500F Circuit Breaker; 2500 amp, 600 volt AC, 3 pole. With 1600 amp trip unit, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2066
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Westinghouse PB32500F Circuit Breaker 2500 Amp 600 Volt AC F/M M/O

Westinghouse PB32500F Circuit Breaker; 2500 amp, 600 volt AC, 3 pole. With 1600 amp trip unit, manually operated (M/O), fixed-mount (F/M). Used tested with report.
SKU: MCCB2067
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FPE NP631090 AB Circuit Breaker 2000 Amp 600 Volt AC M/O F/M

Federal Pacific NP631090 AB Circuit Breaker; 2000 amp, 600 volt AC, 3 pole. With 900 amp trip unit cat# NP631090STP-3, shunt trip- 120 volt AC, manually operated (M/O). fixed-mount (F/M). Used tested with report.
SKU: MCCB2068
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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.