- Thermal element for overcurrent and
- Magnetic element for short circuit release which has to operate faster.
MCCBs are manufactured such that end user will not have access to internal workings of the over-current protection device. Generally constructed of two pieces of heavy-duty electrically insulated plastic, these two halves are riveted together to form the whole. Inside the plastic shell is a series of thermal elements and a Spring-loaded trigger. When the thermal element gets too warm, from an overcurrent situation, the spring trips, which in turn will shut off the electrical circuit.
Types of MCCBs
Current Rating – Amperes
Current Setting Range – Amperes
Short Circuit Rating – Kilo Amperes (KA)
operating Characteristics – Normal / Current Limiting Type
MCCBs are now available with a variety of Releases or Operating Mechanisms these are given below
- Thermal Magnetic Release
- Electronic Release
- Microprocessor Release
Thermal Magnetic Release MCCB
Electronic Release MCCB
Electronic or Static Release Moulded Case circuit breakers use power electronic circuitry to provide overcurrent protection. The Continuous adjustable overload protection from 60% to 100% of the nominal current and short circuit setting from 2 to 10 times of the rated current is possible.
Microprocessor release MCCB
Microprocessor release Moulded Case circuit breakers use microprocessors to provide overcurrent protection. The Microprocessor release works on monitoring of current True R.M.S value. It is simulated and calculated from peak values, which installed microprocessor, can detect.