Elevating your Safety standards with SELVO MCB

As an electrical engineer by profession, I have always been fond of researching and learning about different electrical products that have many applications in the industry. in this article, I will discuss about a brand known for its aesthetically designed and better-quality switchgear range. Although the product range is vast, so will understand and learn about every single product and its types and mechanisms once at a time in each post.
So, I am writing this article on the brand name SELVO which considers paramount factors like compliance with safety standards, reliability, and durability by conducting regular lab tests while manufacturing miniature Circuit breakers.

Power distribution plays a vital role in residential, commercial, and industrial areas, Improvement in the operating mechanism of low voltage switchgear, protection against electrical faults, and greater convenience have become foremost important. SELVO miniature circuit breakers have been designed and manufactured by using components made of high-quality material to fulfill the above objective and meet the changing needs.

Before diving deep into the product specifications of SELVO MCBs, let me brief you about what exactly a ” Miniature Circuit Breaker or MCB ” is. A miniature circuit breaker (MCB) is an electrical switch designed to protect an electrical circuit from damage caused by overload or short circuits. It is a crucial component in electrical distribution systems and ensures the safety of the connected electrical devices and the wiring.

CERTIFICATIONS

Selvo MCBs are accredited with ISO 9001:2015 certifications for adhering to excellent quality product management as part of their production process. The MCB is ISI Marked as per IS/IEC 60898-1:2015 awarded by the Bureau of Indian Standards ( BIS ).

CONSTRUCTION

SELVO MCBs Chassis are made of flame retardant & high-strength thermoplastic material P.B.T
( Polybutylenetheraphthalate ) , It contains essential features such as a high melting point, low water absorption, and high dielectric strength, therefore enabling it to withstand high temperatures.

The contact mechanism comprises fixed and moving contacts to which incoming and outgoing wires are connected. The operating mechanism contains both magnetic tripping and thermal tripping arrangements. These contacts are usually made of materials with good conductivity and are designed for reliable operation.

1. Solenoid
2. Knob or Switch
3. Knob spring
4. Loop Spring
5. Latch
6. Operating spring
7. Operating lever
8. Copper braid wire
9. J Clamp ( or J-shaped terminal )
10. Incoming terminal
11. Grub screw
12. MCB chassis
13. Bi-metallic strip
14. Moving contact
15. Ceramic plate
16. fixed contact
17. Arc chute
18. Din Rail Holder
19. L Terminal
20. Outgoing terminal
21. Terminal Screws
22. Aluminium Pipe

OPERATING PRINCIPLE

SELVO miniature circuit breakers are based on thermal magnetic technology. It uses both thermal and magnetic mechanisms to detect overloads and short circuits, tripping and disconnecting the circuit when necessary to prevent damage and ensure safety.

1.) Thermal Operation: The thermal operation protects from moderate overloads. The MCB is equipped with a bi-metallic strip inside as shown above in Construction heading of number 14 , Under overload conditions which arise When the current flowing through the circuit exceeds the rated value for an extended period thermo-metallic element or bi-metallic strip heats up. The heat causes it to deflect or bend until it operates a latching mechanism allowing the main contacts to open.

2.) Magnetic Operation: During the magnetic operation, a short circuit current actuates a coil or solenoid causing a plunger to strike the latching mechanism & make the latch displaced which separates the main contacts causing MCB to trip and interrupt the circuit.

3.) Arc Extinguishing: Arcing is the formation of an electric arc when the contacts open. MCBs are designed with features to extinguish the arc quickly and safely, preventing damage to the contacts and surrounding components.

4.) Status Indication: When we switch ON MCB, we reset the displaced operating latch mechanism to its previous ON position and make MCB ready for other trip operations. Due to this reason, MCBs are preferred over fuse . Now MCBs have a trip indicator printed on latch, to show whether the breaker is in the ON or OFF position. Generally, when MCB is ON, visual indicators show RED and when it is OFF, it shows green . This helps users identify the status of the circuit quickly.

MCB CHARACTERISTIC CURVE

Based on the tripping characteristic, SELVO MCBs are available in B & C Curve to suit different types of application

1. Type B devices are generally suitable for domestic applications, they may also be used in light commercial applications where switching surges are low or non-existent. Type B devices are designed to trip at fault currents between 3 to 5 times the rated current.
2. Type C devices are normally used for high inductive loads where switching surges are high. Therefore, these are suitable for highly inductive commercial and industrial installations. Type C devices are designed to trip between 5 to 10 times the rated current.

SALIENT FEATURES OF SELVO MCB

Positive Contact Position Indication
_{SELVO MCBs have red and green flag indications giving ON/OFF contact status to identify the real position of contacts inside the MCBs.}

High-Quality Material
_{Selvo MCBs have been manufactured from PBT material, Which is a flame retardant body known for its extra strength & better Insulation properties and silver graphite anti-weld contact tips which ensure the long operating time of the device.}

Large and dual terminating terminal size
_{SELVO MCBs have a high terminal capacity of 35 sq.mm and Bi-connect termination that allows the connection of either cable or busbar single-strip copper for better flexibility.}

Bi-Stable Din Clip Position
_{Selvo MCBs can be conveniently mounted on DIN Rail (the standard size of DIN rail is 35 mm) and can be easily replaced from the bank of devices connected by copper busbar strips without disturbing your existing wiring.}

Air Circulation grooves
_{Selvo MCBs are designed in such a way that provide Sufficient air circulation between the MCBs fixed adjacent to each other and the breathing channels are so profiled that the air circulates individual poles, resulting in cooler operation.}

12 plates Arc Chamber
_{When the contacts are separated in the event of overload or short circuit conditions, an electric arc is formed, then the arc goes up through the arc-runner enters into arc splitters, and is finally quenched.}

 

Ease of clamping
_{The screws are of good quality steel which can be tightened by standard screwdrivers. The maximum Tightening torque is 2Nm.}

IP 20 Degree Protection Safety
_{Selvo MCBs are designed in such a way that they comprise finger-proof terminals which eradicate the chances of accidental contact with live parts which ensures the safety of the installer. Install and operate our MCBs with confidence.}

Energy Saver
_{Selvo MCB has lower wattage loss values as compared to the specification of IS/IEC standards, Due to lower wattage loss it can be termed as energy efficient.}

Ergonomic Dolly/Knob
_{Easy to operate On/Off marking to know the Status of MCB}

Energy Limiting
Class-3
_{Selvo MCBs are designed with a rapid arc quenching mechanism. It operates with the high-speed mechanism in which electrodynamic forces are set up by the heavy current due to a short circuit, Separating the contacts several times faster before they can reach the peak value, thus suppressing the high current}

Breaking capacity 10KA
_{Selvo MCBs are certified to be able to trip while the generation of a high current of 10KA. and protect equipment or appliances from damage.}

TYPES OF SELVO MCB

MCB DIMENSIONS

SPECIFICATIONS

MCB SELECTION CHART AS PER LOAD DEMAND

ESSENTIAL STEPS TO AVOID MCB TRIPPING