MCBs

MCBs, or miniature circuit breakers, are a type of switch used to automatically turn off electrical circuits during abnormal conditions. MCBs often replace fuses in low voltage electrical circuits as they can be more reliable, much more sensitive and are resettable.


How an MCB Works


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 by the use of 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.


MCBs are used to perform many functions such as local control switches, isolating switches against faults and overload protection devices for installation or specific equipment or appliances.


MCB Types


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


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


This type 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.


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


This type 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 value of short circuit currents. Therefore, these are suitable for highly inductive commercial and industrial installations.


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


This type 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. These are suitable for specific industrial and commercial applications. The common examples of such applications include x-ray machines, UPS systems, industrial welding equipment, large winding motors, etc.


How to select a suitable MCB for the application?


Focus on 3 main points to choose the right MCB for the electrical circuit


  1. Ampere rating

  2. Short circuit breaking capacity

  3. Application type

...
Read more Read less

Filters

Viewing 1 - 20 of 2440 products
Results per page
Description Price Number of Poles Current Rating Model Number Range Series Tripping Characteristics Rated AC Voltage Rated DC Voltage Breaking Capacity Mounting Style Length Width Depth Application
RS Stock No. 776-6864
Mfr. Part No.A9F04104
kr 236,65
Each
Units
1 4 A - Acti 9 iC60N Type C 230 V, 400 V 72V 6 kA - 18mm - 91mm -
RS Stock No. 776-6974
Mfr. Part No.A9F04316
kr 811,17
Each
Units
3 16 A - Acti 9 iC60N Type C 440 V 133V 6 kA - 54mm 78.5mm 91mm -
RS Stock No. 776-6915
Mfr. Part No.A9F04204
kr 674,57
Each
Units
2 4 A - Acti 9 iC60N Type C 440 V 133V 6 kA - - - 91mm -
RS Stock No. 776-6912
Mfr. Part No.A9F04210
kr 597,33
Each
Units
2 10 A - Acti 9 iC60N Type C 440 V 133V 6 kA - - 78.5mm 91mm -
RS Stock No. 776-6918
Mfr. Part No.A9F04206
kr 558,19
Each
Units
2 6 A - Acti 9 iC60N Type C 440 V 133V 6 kA - - 78.5mm 91mm -
RS Stock No. 776-2682
Mfr. Part No.A9N21552
kr 531,36
Each
Units
1 + N 1 A - Acti 9 iDPN Type C 230 V - 10 kA - 18mm - 80mm -
RS Stock No. 825-5898
Mfr. Part No.P1MB3PD32
BrandLovato
kr 369,60
Each
Units
3 32 A - ModuLo P1MB Type D 230 V, 400 V - 10 kA - 86.5mm 54mm 79.52mm -
RS Stock No. 746-7703
Mfr. Part No.S202-C4
BrandABB
kr 502,49
Each
Units
2 4 A - System M Pro S200 Type C 400 V - 6 kA - - 35mm 69mm -
RS Stock No. 864-4370
Mfr. Part No.PLSM-D16/2-MW
kr 472,47
Each
Units
2 16 A - xPole PLSM Type D 230 V ac 48V 10 kA - 35mm 80mm 75mm -
RS Stock No. 776-6924
Mfr. Part No.A9F04216
kr 550,54
Each
Units
2 16 A - Acti 9 iC60N Type C 440 V 133V 6 kA - - - 91mm -
RS Stock No. 514-0248
Mfr. Part No.S203-K32
BrandABB
kr 1 026,51
Each
Units
3 32 A - System M Pro S200 Type K 440 V - 6 kA - 88mm - 75.8mm -
RS Stock No. 776-6867
Mfr. Part No.A9F04106
kr 242,09
Each
Units
1 6 A - Acti 9 iC60N Type C 230 V, 400 V 72V 6 kA - - 78.5mm 91mm -
RS Stock No. 776-6851
Mfr. Part No.A9F04102
kr 298,08
Each
Units
1 2 A - Acti 9 iC60N Type C 230 V, 400 V 72V 6 kA - - - 91mm -
RS Stock No. 222-5740
Mfr. Part No.AHC323
BrandEaton
kr 373,03
Each
Units
3 32 A - Memera AHC Type C - - 10 kA - - - - -
RS Stock No. 776-2698
Mfr. Part No.A9N21555
kr 466,56
Each
Units
1 + N 6 A - Acti 9 iDPN Type C 230 V - 10 kA - 18mm - 80mm -
RS Stock No. 776-6760
Mfr. Part No.A9F03104
kr 138,28
Each
Units
1 4 A - Acti 9 iC60N Type B 230 V, 400 V 72V 6 kA - - - 91mm -
RS Stock No. 776-2317
Mfr. Part No.A9F07210
kr 665,88
Each
Units
2 10 A - Acti 9 iC60H Type C 440 V 133V 10 kA - - 78.5mm 91mm -
RS Stock No. 776-6707
Mfr. Part No.A9N21557
kr 466,56
Each
Units
1 + N 16 A - Acti 9 iDPN Type C 230 V - 10 kA - - 70mm 80mm -
RS Stock No. 772-1296
Mfr. Part No.5SY4206-7
BrandSiemens
kr 782,65
Each
Units
2 6 A - Sentron 5SY4 Type C 400 V - 10 kA - 90mm 36mm 76mm -
RS Stock No. 132-122
Mfr. Part No.2CDS272001R0164
BrandABB
kr 667,59
Each
Units
2 16 A - System M Pro S200 Type C 440 V 125V 10 kA - 88mm 35mm 75.8mm -
Related Products
A range of MCB automatic cut-outs in B, ...
Description:
A range of MCB automatic cut-outs in B, C and D characteristics. To secure light, socket outlet and control current circuits. The continuous current corresponds to the nominal current strength of fuse links. These can be replaced by B automatic ...
C60H series are a high performance range of ...
Description:
C60H series are a high performance range of MCBs for direct current networks These are designed for demanding installations to ensure maximum continuity of service. Tripping Curve C. Reliability: guaranteed breaking of DC current for best anti-fire protection. The C60HDC ...
iC60H curve B, C, D circuit breakers are ...
Description:
iC60H curve B, C, D circuit breakers are multi-standard circuit breakers which combine circuit protection against short-circuit currents and circuit protection against overload currents. Visi. Safe guarantees the downstream circuit is always safe, regardless of overvoltage conditions, wear, or operator ...
iDPN is a neutral breaking miniature circuit breaker ...
Description:
iDPN is a neutral breaking miniature circuit breaker used to protect the wires and equipments in the circuit. Visi. Safe for safe operation and maintenance work on circuits. Visi-Trip detects faulty Miniature Circuit-Breaker outgoers quickly and reduces intervention time. Class-2 ...