Molded & Insulated Case Circuit Breakers

Currently shopping by:
  • Functions: LSIG - Long-Time, Short-Time, Instantaneous, Ground
Remove Filter
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.

SPB100 Westinghouse Pow-R Breaker 1600 Amp 600 VAC M/O D/O

Westinghosue SPB100 Pow-R breaker; 1600 amp, 600 volt AC, 3 pole. With 1600 amp rating plug cat.#16SPB1600, Pow-R Trip 7 with LSIG functions, ground fault, manually operated (M/O), draw-out (D/O), used tested with report.
SKU: MCCB1185

SED364000LSGS1A8 Square D Breaker 4000 Amp 600 VAC

Square D SED364000LSGS1A8 breaker; 4000 amp with 3000 amp rating plug cat.#ARP075, shunt trip, micro logic full function series B with LSIG, ground fault, 600 VAC, used tested with report.
SKU: MCCB1377

SED363000LSGES5D4 Square D Breaker 3000 Amp 600 VAC E/O

Square D SED363000LSGES5D4 breaker; series 3, 3000 amp, 600 volt AC, 3 pole. With 3000 amp rating plug cat.#ARP100, micro logic with LSIG functions, ground fault, shunt trip- 24 VDC, with 4 auxiliary switches- 125 VDC/ 120 VAC, 50/60 HZ, integral ground fault- 120 VAC, alarm switch- 120/240 VAC, electrically operated (E/O), used tested with report.
SKU: MCCB1359

SBS612 Eaton/ Cutler-Hammer Magnum SB 1200 Amp 600 VAC M/O D/O

Eaton/ Cutler-Hammer SBS612 Magnum SB; cat.# SBS6123WEA, 1200 amp, 600 volt AC, 3 pole. With Digitrip 520 trip unit cat.# 5LSIG, LSIG functions, ground fault, 1000 amp rating plug, auxiliary switches, manually operated (M/O), draw-out (D/O) with draw-out carriage, used tested with report.
SKU: MCCB1673

SBS612 Eaton/Cutler-Hammer Magnum SB 1200 Amp 600 VAC M/O D/O

Eaton/Cutler Hammer SBS612 Magnum SB; cat.# SBS6123WEA, 1200 amp, 600 volt AC, 3 pole. With Digitrip 520 trip unit cat.# 5LSIG, 1000 amp rating plug, auxiliary switches, manually operated (M/O), draw-out (D/O) with draw-out carriage, used tested with report.
SKU: MCCB1672

SBS4000 Siemens Breaker 4000 Amp 600 VAC MO/STA

Siemens SBS 4000 breaker; cat.# SBS4040F, 4000 amp, 600 volt AC, 3 pole. With trip unit cat.# SB40TLSIG, LSIG functions, ground fault, 3000 amp rating plug, manually operated, stationary, used tested with report.
SKU: MCCB24538

SBS2020 Siemens Breaker 2000 Amp 600 VAC M/O D/O

Siemens SBS2000 circuit breaker** cat.# SBS2020, 2000 amp, 600 volt AC, 3 pole. With trip unit cat.# SB20TLSIG, LSIG functions, ground fault, 2000 amp rating plug cat# 20SB2000, manually operated (M/O), draw-out (D/O), used tested with report.
SKU: MCCB22328

SBH1600 Siemens Breaker 1600 Amp 600 VAC E/O D/O

Siemens SBH1600 circuit breaker; cat.# SBH2016DV, 1600 amp, 600 volt AC, 3 pole. With 1200 amp rating plug cat.# 16SB1200, shunt trip #SBST24, auxiliary switches #SBAS8, bell alarm #SBBA120, electrical operator # SBEO120, draw-out carriage # SBH20DFV, electrically operated (E/O), draw-out (D/O), used tested with report.
SKU: MCCB1775

SBH 4000 Siemens SBH4040 Circuit Breaker 4000 Amp 600 VAC MO/FM

Siemens SBH 4000 breaker cat.# SBH4040, 4000 amp trip unit cat.# SB40TLSIG with LSIG functions, 4000 amp rating plug, 600 VAC, manually operated, fixed mount, used tested with report.
SKU: MCCB22309

HND212T36W Cutler-Hammer Circuit Breaker

Cutler-Hammer HND212T36W circuit breaker; 1200 amp, 600 volt, two pole, 65 kAIC @ 480 volt AC with LSIG. 600, 700, 800, 900, 1000 and 1200 amp trips available, used electrically OK.
SKU: HND212T36W
Contact us for pricing:

HND2800T36W Cutler-Hammer Circuit Breaker

Cutler-Hammer HND2800T36W circuit breaker; 800 amp, 600 volt, two pole, 65 kAIC @ 480 volt AC with LSIG. 400, 450, 500, 600, 700 and 800 amp trips available, used electrically OK.
SKU: HND2800T36W
Contact us for pricing:

HND312T36W Cutler-Hammer Circuit Breaker

Cutler-Hammer HND312T36W circuit breaker; 1200 amp, 600 volt, three pole, 65 kAIC @ 480 volt AC with LSIG. 600, 700, 800, 900, 1000 and 1200 amp trips available, line & load side lugs. Used tested with report.
SKU: HND312T36W

HND3800T36W Cutler-Hammer Circuit Breaker

Cutler-Hammer HND3800T36W circuit breaker; 800 amp, 600 volt, three pole, 65 kAIC @ 480 volt AC with LSIG. 400, 450, 500, 600, 700 and 800 amp trips available, used tested with report.
SKU: HND3800T36W
Contact us for pricing:

M40H1 Merlin-Gerin Masterpact Circuit Breaker 4000 Amp 600 VAC M/O D/O

Merlin-Gerin M40H1 Masterpact circuit breaker: 4000 amp, 600 volt AC. STR58U trip unit with LSIG, ground fault, manually operated (M/O), draw-out (D/O) with draw-out cubicle, used tested with report.
SKU: MCCB1379

Cutler-Hammer MDSC16 Magnum DS Circuit Breaker 1600 Amp 600 VAC M/O D/O Tested

Cutler-Hammer/ Eaton MDSC16 Magnum DS low voltage AC power circuit breaker: cat.#MDSC163WEA12MHA, 1600 amp, 600 volt AC. With 1600 amp rating plug. Digitrip 520M cat.#5MLSIG with LSIG functions, shunt trip- 110/127 VAC, 110/125 VDC, auxiliary switches. Manually operated (M/O), draw-out (D/O), draw-out carriage cat.# MN203PADNNNNNNC, used tested with report.
SKU: MCCB1439

Cutler-Hammer Magnum DS MDSC16 Circuit Breaker 1600 Amp 600 VAC M/O D/O

Cutler-Hammer/ Eaton MDSC16 Magnum DS low voltage AC power circuit breaker; cat# MDSC163WEA12MHA, 1600 amp, 600 volt AC, 3 pole. With 1600 amp rating plug, Digitrip 520M cat.#5MLSIG, LSIG functions, ground fault, shunt trip- 110/127 VAC, 110/125 VDC, auxiliary switches, manually operated (M/O), draw-out (D/O), draw-out carriage cat.# MN203PADNNNNNNC, used tested with report.
SKU: MCCB1440

Cutler-Hammer Magnum DS MDSC16 Circuit Breaker 1600 Amp 600 VAC M/O D/O

Cutler-Hammer/Eaton MDSC16 Magnum DS low voltage AC power circuit breaker; cat # MDSC163WEA12MHA, 1600 amp, 600 volt AC, 3 pole. With Digitrip 520M cat.# 5MLSIG, LSIG functions, ground fault, 1600 amp rating plug, shunt trip- 110/127 VAC, 110/125 VDC, manually operated (M/O), draw-out (D/O), draw-out carriage cat.# MN203PADNNNNNNC, used tested with report.
SKU: MCCB1454

Square D Masterpact MP12H1 Circuit Breaker 1200 Amp 600 VAC D/O E/O

Square D MP12H1 Masterpact circuit breaker; 1200 amp, 600 volt AC, 3 pole. With STR 58U trip unit with LSIG functions, ground fault, 1200 amp rating plug cat.# 54750, auxiliary switch, shunt trip, overcurrent trip switch, LT alarm, motor & charged switch, closing release, Ext. CT, draw-out (D/O), electrically operated (E/O), used tested with report.
SKU: MCCB1796

Merlin Gerin Masterpact MP16H1 Circuit Breaker 1600 Amp 600 VAC D/O E/O

Merlin Gerin MP16H1 Masterpact circuit breaker; 1600 amp, 600 volt AC, 3 pole. With STR 58U trip unit, LSIG functions, ground fault, 1600 amp rating plug cat.# 54754, auxiliary switch, overcurrent trip switch, LT alarm, motor & charged switch, draw out (D/O), electrically operated (E/O), used tested with report.
SKU: MCCB1795

Merlin-Gerin Masterpact MP20H1 Circuit Breaker 2000 Amp 600 VAC E/O D/O

Merlin-Gerin MP20H1 Masterpact circuit breaker: 2000 amp, 600 volt AC, 3 pole. With 2000 amp rating plug cat# 54758, STR38S trip unit with LSIG functions, ground fault, overcurrent trip switch, auxiliary switches, shunt trip, alarm switch, electrically operated (E/O), draw-out (D/O), draw-out cubicle, used tested with report.
SKU: MCCB1385

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.