MCB (Miniature circuit breakers) is an electrical switch which operates automatically in case of fault and excessive current. Selection of MCB depend upon the connected your household devices, however for light load equipment like fridge, Single phase AC, water motor, fans & for illumination lamps 2 Pole, 10A MCB is suitable & for Three phase higher load like heavy water motor, Geyser, 2 Ton Air Condition 16A or 32A, 4 Pole MCB shall be required.
What is MCB?
MCB full from is Miniature circuit breakers, that means small electrically operated switch. When we install rooftop solar system, solar installation accessories play important role. There are some important components of this, such as DC Wire, Earthing Kit, DCDB, ACDB, MCB, etc. In this blog, you will know the complete buying guide of MCB. So, let’s continue reading…
As we know MCB is an electrical switch which operates automatically in case of fault and protects the connected equipment from heavy current. MCB are designed to trip during an overload or short circuit condition to protect against electrical faults and equipment failure. In old days commonly use fuse at homes to protect the appliances in case of overload and heavy current flow. But operation of fuse is not reliable and replacement is an issue in fuse hence MCB automatically shut down and the fault of the device can be easily detected.
How does MCB Work?
When the short circuit or overload condition occur, higher current flow occurs through MCB, the connected bimetallic strip in to MCB gets heated and deflects by bending. The deflection of the bi-metallic strip releases a latch. The latch causes the MCB to turn off by disconnecting the current flow in the circuit. This MCB operation helps to safeguard the home appliances or devices from the hazards of over current. Once the fault removed from circuit you can operate MCB manually to restart the current flow in circuit.
How many types of MCB?
Based on the application & design several type (A-Type, B-Type, C Type, D-type, K-type & Z-type) of MCB available in market; however for general & domestic purpose we use Type-B & Type-C MCBs.
As mentioned type of MCB’s are calcified based on design and applicable like
Type-A MCB can use in semiconducting device & it will trip when fault current reach 2-3 time of rated current value.
Type-B MCB can use in most of domestic appliances & it will trip when fault current reach 3-5 time of rated current value.
Type-C MCB can also use in domestic appliances like Heater, stabilizer, Air-Condition, Printer & it will trip when fault current reach 5-8 time of rated current value.
Type-D MCB can also use in domestic & industrial appliances like motor, lift & it will trip when fault current reach 10-20 time of rated current value and offer high resistance.
Type-K MCB can also use where fault current is about 9-13 time of rated current value and used in heavy-duty load devices like compressors, winding motors, and X-ray.
Application of each MCB is different & depends upon the type of MCB. However for light load device type-A, B & C MCB can used & for heavy duty drives & in such device having high starting current can use Type- D & K MCB’s.
MCB Rating List & Price
A wide ampere range & type of MCB starting from 2.4A to 200A rating is available in market. However these are mainly used MCBs in home and solar system:
MCB Brands (Manufactures) in India
So many local and global manufacturers are available in Indian market with variation in design and cost, however following makes of MCB’s are good and best in customer support like Siemens, L&T, ABB, Schneider, Polycab, Legrand, sigma, Hager etc.
Why MCB Trip Again and Again?
There might be two- three possibilities, one if phase to neutral or phase to phase wire shorted due to over heating or running overload for long duration. And second if the connected device is running overload and that time current reaches 2-3 time of rated current, than it will trip.
Also selection of wrong type of MCB causes tripping, like in Motor required higher starting current so you need to select Type-C for that & if you have selected Type-B MCB than its trip again and again during starting.
How much ampere MCB required for 1.5-ton AC?
If AC is single phase than the required MCB Type-C 16Amp, 2Pole is sufficient but if the AC required three phase supply than 10A, 4P MCB shall be required.
How to select MCB Rating?
Based on the application and requirement you can select the MCB rating, however the following criteria are listed below,
- Based on the required rated current
- Based on MCB tripping characteristic
- Based on the number of pole
- Breaking current
MCB (Miniature Circuit Breakers) is advanced, reliable safeguard & more sensitive to current than fuse. As compare MCB is much more reliability than fuse and best part is easy to replace, availability in market and operation. Also MCB are available in wide range of current rating and ability to perfume different-2 type of tripping zones to make MCB more advance. Please visit www.loomsolar.com for more detail on MCB.