MCBs

MCBs, or miniature circuit breakers, are a type of switch used to automatically turn off electrical circuits during abnormal conditions. Often replacing fuses in low voltage electrical circuits as they are more reliable, more sensitive and are resettable. Miniature circuit breakers are designed to protect electric circuits from overcurrent.

Typically mounted on DIN Rail and used in consumer units and distribution boards in a range of industrial, commercial, and domestic applications. You can learn more about MCBs in our complete MCB guide.

RS Components offer a comprehensive selection of high-quality Miniature Circuit Breakers from industry-leading brands including ABB, Siemens, Schneider Electric, Eaton, Rockwell Automation and Lovato.

How does a miniature circuit breaker work?

When continuous overcurrent flows through an MCB, a bimetallic strip is heated and causes it to bend. This bending of the bimetallic strip releases a mechanical latch opening the contacts and turning off the MCB, thereby stopping the current to flow in the circuit.

To restart the flow of current the MCB must be manually turned on. This mechanism protects the MCB from faults arising due to overcurrent or overload and is intended to prevent the accidental overloading of the cable in a no-fault situation.

The speed of the MCB tripping will vary with the degree of the overload. This is usually achieved using a thermal device in the MCB.

The second characteristic is the magnetic fault protection, which is intended to operate when the fault reaches a predetermined level and to trip the MCB within one-tenth of a second. The level of this magnetic trip gives the MCB its type characteristic.

What are the different types of circuit breakers?

There are three common types of electrical circuit protection in residential, commercial, and industrial applications. The use is classified by a curve type, which determines the tripping characteristics of the MCB:

Curve B - trips between 3 and 5 times the load current

Type B will trip instantly at a rate of three to five times its rated current. These are normally used for resistive or small inductive loads where switching surges are very small. Therefore, these are suitable for residential or light commercial installations.

Curve C - trips between 5 and 10 times the full load current

Type C will trip instantly at a rate of five to ten times its rated current. These are normally used for high inductive loads where switching surges are high such as small motors and fluorescent lighting. In such cases, type C MCBs are preferred to handle higher values of short circuit currents

Curve D - trips between 10 and 20 times the full load current

Type D will trip instantly at a rate of ten to twenty-five times its rated current. These are normally used for very high inductive loads where high inrush current is very frequent. Applications include x-ray machines, UPS systems, industrial welding equipment, large winding motors, etc.


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Description Price Number of Poles Current Rating Series Tripping Characteristics Rated AC Voltage Breaking Capacity at Maximum Voltage Rating Rated DC Voltage Model Number Range Breaking Capacity Circuit Breaker Type Mounting Style Length Width
RS Stock No. 776-6864
Mfr. Part No.A9F04104
kr 236,65
Each
Units
1P 4A iC60N Type C 230 V, 400V 6 kA 72V - Acti 9 - MCB DIN Rail Mount 18mm -
RS Stock No. 776-6974
Mfr. Part No.A9F04316
kr 811,17
Each
Units
3P 16A iC60N Type C 440V 6 kA 133V - Acti 9 - MCB DIN Rail Mount 54mm 78.5mm
RS Stock No. 776-6915
Mfr. Part No.A9F04204
kr 674,57
Each
Units
2P 4A iC60N Type C 440V 6 kA 133V - Acti 9 - MCB DIN Rail Mount - -
RS Stock No. 776-6912
Mfr. Part No.A9F04210
kr 597,33
Each
Units
2P 10A iC60N Type C 440V 6 kA 133V - Acti 9 - MCB DIN Rail Mount - 78.5mm
RS Stock No. 776-6918
Mfr. Part No.A9F04206
kr 558,19
Each
Units
2P 6A iC60N Type C 440V 6 kA 133V - Acti 9 - MCB DIN Rail Mount - 78.5mm
RS Stock No. 825-5898
Mfr. Part No.P1MB3PD32
BrandLovato
kr 713,16
Each
Units
3P 32A P1MB Type D 230 V, 400V 10 kA - - ModuLo - MCB DIN Rail Mount 86.5mm 54mm
RS Stock No. 746-7703
Mfr. Part No.2CDS252001R0044 S202-C4
BrandABB
kr 545,84
Each
Units
2P 4A S200 Type C 400V 6 kA - S202-C4 System Pro M Compact - MCB DIN Rail Mount - 35mm
RS Stock No. 776-2682
Mfr. Part No.A9N21552
kr 531,36
Each
Units
- 1A iDPN Type C 230V 10 kA - - Acti 9 - MCB DIN Rail Mount 18mm -
RS Stock No. 776-6851
Mfr. Part No.A9F04102
kr 298,08
Each
Units
1P 2A iC60N Type C 230 V, 400V 6 kA 72V - Acti 9 - MCB DIN Rail Mount - -
RS Stock No. 514-0248
Mfr. Part No.2CDS253001R0537 S203-K32
BrandABB
kr 1 115,54
Each
Units
3P 32A S200 Type K 440V 6 kA - S203-K32 System Pro M Compact - MCB DIN Rail Mount 88mm -
RS Stock No. 864-4370
Mfr. Part No.242428 PLSM-D16/2-MW
BrandEaton
kr 579,60
Each
Units
2P 16A PLSM Type D - 10 kA 48V - xPole - MCB DIN Rail Mount 35mm 80mm
RS Stock No. 776-6867
Mfr. Part No.A9F04106
kr 242,09
Each
Units
1P 6A iC60N Type C 230 V, 400V 6 kA 72V - Acti 9 - MCB DIN Rail Mount - 78.5mm
RS Stock No. 776-6924
Mfr. Part No.A9F04216
kr 550,54
Each
Units
2P 16A iC60N Type C 440V 6 kA 133V - Acti 9 - MCB DIN Rail Mount - -
RS Stock No. 776-6760
Mfr. Part No.A9F03104
kr 138,28
Each
Units
1P 4A iC60N Type B 230 V, 400V 6 kA 72V - Acti 9 - MCB DIN Rail Mount - -
RS Stock No. 776-6707
Mfr. Part No.A9N21557
kr 466,56
Each
Units
- 16A iDPN Type C 230V 10 kA - - Acti 9 - MCB DIN Rail Mount - 70mm
RS Stock No. 132-122
Mfr. Part No.2CDS272001R0164 S202M-C16
BrandABB
kr 725,31
Each
Units
2P 16A S200M Type C 440V 10 kA 125V S202M-C16 System Pro M Compact - MCB DIN Rail Mount 88mm 35mm
RS Stock No. 772-1296
Mfr. Part No.5SY4206-7
BrandSiemens
kr 1 053,44
Each
Units
2P 6A 5SY4 Type C 400V 10 kA - - Sentron - MCB DIN Rail Mount 90mm 36mm
RS Stock No. 776-2317
Mfr. Part No.A9F07210
kr 665,88
Each
Units
2P 10A iC60H Type C 440V 10 kA 133V - Acti 9 - MCB DIN Rail Mount - 78.5mm
RS Stock No. 488-6296
Mfr. Part No.S201-C6
BrandABB
kr 175,87
Each
Units
1P 6A S200 Type C 253V 6 kA 72V S201-C6 System Pro M Compact - MCB DIN Rail Mount 88mm 17.5mm
RS Stock No. 772-1278
Mfr. Part No.5SY4202-7
BrandSiemens
kr 1 053,44
Each
Units
2P 2A 5SY4 Type C 400V 10 kA - - Sentron - MCB DIN Rail Mount 90mm 36mm