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

...
Voir plus Voir moins

Filtres

Afficher 81 - 100 des 2240 produits
Nombre de résultats par page
Description Prix 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
N° de stock RS 776-6716
Référence fabricantA9N21561
49,25 €
Each
Unité
1 + N 40 A - Acti 9 iDPN Type C 230 V - 10 kA - 18mm - 80mm -
N° de stock RS 734-9680
Référence fabricantA9F75420
146,40 €
Each
Unité
4 20 A - Acti 9 iC60N Type D 400 V, 440 V, 100 → 130 V, 12 → 60 V, 220 → 240 V, 380 → 415 V 12 → 250V 6 kA - - - - -
N° de stock RS 922-6898
Référence fabricant102084 | FAZ-C6/1-NA
MarqueEaton
26,33 €
Each
Unité
1 6 A - xEffect FAZ Type C 240 → 415 V 48V 10 kA - 17.8mm 65.5mm 80mm Computers, Control Instrumentation, External Load Circuit, HACR Internal/External Equipment, Internal/External Convenience Receptacle Circuit, Motor Control Circuit, PLC I/O Point, Power Conditioner, Power Supplies, Relay, Uninterruptable Power Supplies
N° de stock RS 769-4738
Référence fabricant168062 | FAZ6-D10/1
MarqueEaton
17,16 €
Each
Unité
1 10 A - xEffect FAZ6 Type D 230 → 400 V - 6 kA - 80mm 17.5mm 61.5mm -
N° de stock RS 776-6757
Référence fabricantA9N21726
83,50 €
Each
Unité
1 + N 13 A - Acti 9 iDPN Type D 400 V - 6 kA - 54mm 70mm 90mm -
N° de stock RS 734-9668
Référence fabricantA9F75220
72,29 €
Each
Unité
2 20 A - Acti 9 iC60N Type D 400 V, 440 V, 100 → 130 V, 12 → 60 V, 220 → 240 V, 380 → 415 V 12 → 144V 6 kA - - 36mm - -
N° de stock RS 825-5716
Référence fabricantP1MB2PC10
MarqueLovato
23,32 €
Each
Unité
2 10 A - ModuLo P1MB Type C 230 V, 400 V 80V 10 kA - 86.5mm 36mm 79.52mm -
N° de stock RS 535-4245
Référence fabricant2CDS273001R0044
MarqueABB
104,30 €
Each
Unité
3 4 A - System M Pro S200 Type C 440 V - 10 kA - - 52.5mm 75.8mm -
N° de stock RS 435-550
Référence fabricant2CCS891001R0631
MarqueABB
108,50 €
Each
Unité
1 63 A - High Performance S800 Type D 400 V, 690 V - 6 kA - - 26.5mm 88.5mm -
N° de stock RS 847-3285
Référence fabricant102170 | FAZ-C16/2-NA
MarqueEaton
61,92 €
Each
Unité
2 16 A - xEffect FAZ Type C 240 → 415 V - 10 kA - 35.4mm 105mm 75.5mm -
N° de stock RS 521-4709
Référence fabricant5SJ6210-6KS
MarqueSiemens
38,25 €
Each
Unité
2 10 A - Sentron 5SJ6 Type B 230 V, 400 V 60V 6 kA - 90mm 36mm 76mm -
N° de stock RS 731-9477
Référence fabricant4 076 96
MarqueLegrand
69,07 €
Each
Unité
1 + N 6 A - DX Range DX3 Type C 230 V - 10 kA - - - - -
N° de stock RS 847-3308
Référence fabricant278761 | FAZ-C20/2
MarqueEaton
55,50 €
Each
Unité
2 20 A - xEffect FAZ Type C 240 → 415 V - 10 kA - 36mm 84.7mm 72.6mm -
N° de stock RS 849-6531
Référence fabricantEUC2P2C
MarqueEuropa
15,55 €
Each
Unité
2 2 A - EU EUC Type C 230/400 V - 10 kA - 36mm 78mm 87mm -
N° de stock RS 532-5045
Référence fabricant278609 | FAZ-S4/1
MarqueEaton
15,20 €
Each
Unité
1 4 A - xEffect FAZ Type S 230 V - 10 kA - 80mm 17.5mm 73.5mm -
N° de stock RS 131-410
Référence fabricantPKNM-10/2/C/003
MarqueEaton
83,82 €
Each
Unité
- - - - - - - - - - - - - -
N° de stock RS 790-7361
Référence fabricantA9C65340
245,39 €
Each
Unité
3 40 A - Acti 9 iC60H Type C 220 → 240 V, 380 → 415 V 24V 10 kA - - 84mm 77mm -
N° de stock RS 922-6967
Référence fabricant278529 | FAZ-B6/1
MarqueEaton
20,54 €
Each
Unité
1 6 A - xEffect FAZ Type B 240 V 48V 10 kA - 17.8mm 65.5mm 80mm Appliances, Business Equipment, Control Circuit, Lighting, Supplementary Protection
N° de stock RS 825-5728
Référence fabricantP1MB2PC20
MarqueLovato
23,32 €
Each
Unité
2 20 A - ModuLo P1MB Type C 230 V, 400 V 80V 10 kA - 86.5mm 36mm 79.52mm -
N° de stock RS 922-7037
Référence fabricant278580 | FAZ-D10/1
MarqueEaton
32,38 €
Each
Unité
1 10 A - xEffect FAZ Type D 240 V 48V 10 kA - 17.8mm 65.5mm 80mm Appliances, Business Equipment, Control Circuit, Lighting, Supplementary Protection