Molded Case Circuit Breakers

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Molded case circuit breakers protect various electrical circuits and equipment from overcurrents and short circuits. These breakers consist of a molded case housing that encloses the circuit... Read More

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PowerPact R Frame Molded Case Circuit Breaker, 1600A, 600V

PowerPact R Frame Molded Case Circuit Breaker, 1600A, 600V
ModelItemPrice (inc. GST)
RJF36160U44ACE6HJZA$ 31471.71
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Molded Case Circuit Breaker, Thermal Magnetic Trip, 600 VAC

Molded Case Circuit Breaker, Thermal Magnetic Trip, 600 VAC
ModelItemPrice (inc. GST)
HJM36100CE6JPBA$ 2261.58
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Molded Case Circuit Breaker, Bolt On, 100A, 600VAC

Molded Case Circuit Breaker, Bolt On, 100A, 600VAC
ModelItemPrice (inc. GST)
NFNF36100CE6JGYA$ 1625.98
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Miniature Circuit Breaker, 3A, 277 VAC/ 60 VDC, 1-Pole, D Curve, Thermal Magnetic

Miniature Circuit Breaker, 3A, 277 VAC/ 60 VDC, 1-Pole, D Curve, Thermal Magnetic
ModelItemPrice (inc. GST)
GMCBU-1D-3CV7FEXA$ 51.20
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Molded Case Circuit Breaker, 50kAIC at 240V, 1200A, 600V

Molded Case Circuit Breaker, 50kAIC at 240V, 1200A, 600V
ModelItemPrice (inc. GST)
NAL361200CE6HJD-
RFQ
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Molded Case Circuit Breaker, 1200A, 600V, Load Lugs

Molded Case Circuit Breaker, 1200A, 600V, Load Lugs
ModelItemPrice (inc. GST)
PGM36120CU31ACE6HJL-
RFQ
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Molded Case Circuit Breaker, 400A, Electronic Trip, 18kAIC

Molded Case Circuit Breaker, 400A, Electronic Trip, 18kAIC
ModelItemPrice (inc. GST)
DGL36400E20CE6HJM-
RFQ
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PowerPact Molded Case Circuit Breaker, 1200A, 480V

PowerPact Molded Case Circuit Breaker, 1200A, 480V
ModelItemPrice (inc. GST)
PLM34120CU44ACE6HJY-
RFQ
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Molded Case Circuit Breaker, 3P, 100A, 240V, 10kAIC, 3 Phase

Molded Case Circuit Breaker, 3P, 100A, 240V, 10kAIC, 3 Phase
ModelItemPrice (inc. GST)
Q1L3100CE6HKU-
RFQ
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PowerPact H Circuit Breaker, 125A, Thermal Magnetic Trip

PowerPact H Circuit Breaker, 125A, Thermal Magnetic Trip
ModelItemPrice (inc. GST)
HGP36125CE6JMD-
RFQ
1...4445

Molded Case Circuit Breakers

Molded case circuit breakers are designed to prevent the flow of faulty power supplies into sensitive electrical equipment that may cause overloads and short circuits. With current ratings up to 1600A, these units are ideal for isolation applications in large PV systems. Raptor Supplies offers a wide range of these MCCBs from brands like ABB, Square D, Eaton, General Electric and Siemens. Square D circuit breakers come equipped with a thermal-magnetic trip unit which instantly opens under faulty currents and are capable of providing both time-delayed and instantaneous current limiting functions. These units feature an I-line type configuration at the ON end for facilitating bus connections in panelboards and lugs at the OFF end for cable connection. General Electric molded case circuit breakers feature a programmable electronic trip unit which accentuates the toggle when the current exceeds the predetermined value. These breakers come equipped with bolt-on type terminals for easy installation in reverse-feed applications. They are available in 2 and 3 pole options with a maximum voltage rating of 600VAC on Raptor Supplies.

Working Mechanism

Molded case circuit breaker's working mechanism includes following steps:

  • In the normal state, molded case circuit breakers allow electrical current to flow through the circuit uninterrupted.
  • When an overcurrent condition occurs, the MCCB's internal sensors detect the excess current flowing through the circuit.
  • They have two main trip mechanisms: electromagnetic trip and thermal trip.
  • The electromagnetic trip detects sudden, high-current surges, similar to short circuits, and quickly opens the circuit to cut power.
  • The thermal trip reacts to prolonged overloads by heating up, causing the MCCB to trip and disconnect the circuit.
  • Once the trip mechanism is activated, it triggers a mechanical release within the circuit breaker.
  • Hence, the breaker's contacts move quickly to the open position.
  • When the contacts are open, the MCCB interrupts the electrical flow, effectively cutting off power to the circuit.
  • The circuit remains in this disconnected state until manually reset by the user.

Features

General Electric Bolt-On Circuit Breakers:

  • These General Electric TEYH Series MCCBs have a thermal-magnetic, non-interchangeable trip unit to protect from severe power surges while avoiding tripping on mild overloads.
  • They also have a bolt-on mounting facility for convenience and compatibility with lug-lug / unit-mount applications.
  • These UL-listed breakers are available in single, two and three-pole configurations and accommodate universal 10 to 4 AWG size wires.

Square D PowerPacT Circuit Breakers :

  • These Square D MCCBs have a new front-facing and semi-transparent cover for easy access to accessories.
  • They have current ratings ranging from 15 to 125A and offer a maximum breaking capacity of 65kA at 480VAC.
  • These RoHS and REACH-compliant breakers feature dual-break rotating contacts that reduce peak current during a short circuit fault.

Eaton HKD Series Circuit Breakers :

  • Eaton HKD Series circuit breakers protect against overload and short circuit conditions in 480Y / 277V (three-phase, four-wire) distribution panels.
  • They have 2-pole construction and can serve two separate circuits or a complete single circuit when short-circuited.

Frequently Asked Questions

How does a molded case circuit breaker differ from a circuit breaker?

While both molded case circuit breakers and conventional circuit breakers serve the same primary purpose of protecting electrical circuits, MCCBs are a specific type of circuit breaker with a molded case for added durability and protection.

Can MCCBs be reset after tripping?

Once the fault or overload is resolved, you can reset the MCCB to restore power to the circuit.

What is the difference between an MCCB and a miniature circuit breaker (MCB)?

Molded case circuit breakers are designed for higher current ratings and are used in industrial settings with heavy machinery, while MCBs are smaller and designed for residential or light commercial applications with lower current ratings.

Can MCCBs be used in three-phase electrical systems?

Yes, MCCBs are commonly used in three-phase systems. Brands like WEG, Siemens and ABB come in various configurations to suit single-phase or three-phase applications.

How do I select the right MCCB for my specific application?

Selecting the right MCCB involves considering factors such as the system's voltage, current rating, environmental conditions and specific protection requirements.

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