MCB (Miniature Circuit Breaker), Construction, Working, Types & Uses
https://www.electricaltechnology.org/2016/02/mcb-miniature-circuit-breaker-types-construction-working-uses.html
MCBs are used primarily as an alternative to the fuse switch in most of the circuits.
A wide variety of MCBs have been in use nowadays in all areas of domestic, commercial and industrial applications as a reliable means of protection.
Air Circuit Breaker (ACB) – Construction, Operation, Types and Uses
https://www.electricaltechnology.org/2014/11/air-circuit-breaker-operation-types-uses.html
Circuit breakers are widely used in industries as well as power system for controlling and protection of different parts of the circuit like switch gears, Transformers, Motors, Generators/Alternator etc., which leads the system stable and reliable
18 Comments
Ann Moody says:
A circuit breaker, designed to protect an electrical circuit, is an automatically operated electrical switch.
Portable Generators
Tomi Engdahl says:
https://www.electricaltechnology.org/2015/08/how-to-read-mcb-nameplate-data-rating.html
Tomi Engdahl says:
https://www.electricaltechnology.org/2020/03/overcurrent-overload-overvoltage.html
Tomi Engdahl says:
Electronic Circuit Breaker – Schematic and Working
https://www.electricaltechnology.org/2020/04/electronic-circuit-breaker-schematic-working.html
Tomi Engdahl says:
https://www.electricaltechnology.org/2020/04/electronic-circuit-breaker-schematic-working.html
Tomi Engdahl says:
E-fuses: warming up to higher-current applications
https://www.edn.com/e-fuses-warming-up-to-higher-current-applications/
The brief note explained the ins and outs of e-fuses with respect to these regulations, and it also reminded me of a point that it’s easy to overlook: fuses protect against overcurrent situations and the risk they pose to systems and people. They are not for high-voltage protection, even though we may unconsciously associate “danger” with AC-line voltage of 120/240V and the large amounts of current AC lines can deliver. The TI note lists approved e-fuses that go up to 4.5 to 60V at 6 A – clearly not line voltage, but still a substantial amount of current and double-digit voltage. Protection against high-voltage events is not a task for a fuse; instead, that is the role of MOVs, spark gaps, and other components.
Tomi Engdahl says:
How to calculate proper fuse for safety purpose
https://m.youtube.com/watch?feature=youtu.be&v=-1d7yfpjK-4
Tomi Engdahl says:
https://www.electricaltechnology.org/2016/02/mcb-miniature-circuit-breaker-types-construction-working-uses.html
Tomi Engdahl says:
Modernizing Circuit Protection for Industry 4.0
Circuit protection has proven useful, but meeting the increasingly sophisticated industrial and commercial requirements can be a challenge.
https://www.electronicdesign.com/power-management/whitepaper/21135193/modernizing-circuit-protection-for-industry-40?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS200625066&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R
Tomi Engdahl says:
https://www.edn.com/the-big-breaker-mistake/?utm_source=newsletter&utm_campaign=link&utm_medium=EDNWeekly-20200723
Tomi Engdahl says:
FuN
https://amp.reddit.com/r/funny/comments/2sxuux/fuse_replacement_guide/
Tomi Engdahl says:
Standards and description of circuit-breakers
https://www.electrical-installation.org/enwiki/Standards_and_description_of_circuit-breakers
Tomi Engdahl says:
https://www.electrical-installation.org/enwiki/Standards_and_description_of_circuit-breakers
For industrial LV installations the relevant IEC standards are, or are due to be:
60947-1: general rules
60947-2: part 2: circuit-breakers
60947-3: part 3: switches, disconnectors, switch-disconnectors and fuse combination units
60947-4: part 4: contactors and motor starters
60947-5: part 5: control-circuit devices and switching elements
60947-6: part 6: multiple function switching devices
60947-7: part 7: ancillary equipment
60947-8: Part 8: Control units for built-in thermal protection (PTC) for rotating electrical machines.
IEC 60947-2:2016+AMD1:2019 CSV
Consolidated version
Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
https://webstore.iec.ch/publication/65448
Tomi Engdahl says:
Failed elevator switch fuse / fusible disconnect
https://www.youtube.com/watch?v=9WW0hBkxUnA
This is a common industrial grade switch-fuse unit used for isolation and protection. The unit in this video had failed, so I thought it would be interesting to see what had gone wrong.
Tomi Engdahl says:
What Is a Main Circuit Breaker?
https://www.thespruce.com/what-is-a-main-breaker-1152730
Tomi Engdahl says:
Defining short-circuit values for circuit breakers
https://new.abb.com/news/detail/11829/defining-short-circuit-values-for-circuit-breakers
Circuit breakers protect electrical equipment from damage that may arise from short-circuit currents. However, the “short-circuit current” can vary depending on the application. How do IEC and EN standards help designers properly specify overcurrent protection in electrical equipment?
Standards relating to circuit breakers
Depending on the particular application, different standards may be referred to when a designer is specifying circuit breakers or associated equipment for power network protection:
• The IEC/EN 60898-1 standard applies to circuit breakers for overcurrent protection in households and similar installations – for example, shops, offices, schools and small commercial buildings. These breakers are designed to be operated by uninstructed people and without the need for maintenance.
• The IEC/EN 60947-2 standard applies to circuit breakers used mainly in industrial applications where only instructed people have access.
• Switch-disconnectors are tested against the IEC/EN 60947-3 standard.
• Switchgear assembly or distribution boards are tested against the IEC/EN 61439 standard.
Due to the different scope of the standards, in some cases, different definitions are used for the same electrical process. The engineer must, therefore, ensure that he fully understands which particular definition, for, say, short-circuit capacity, applies to the design he is working on.
Circuit breakers and IEC/EN 60898-1
IEC/EN 60898-1 defines the rated short-circuit capacity (Icn) as the breaking capacity according to a specified test sequence.
Circuit breakers and IEC/EN 60947-2
IEC/EN 60947-2 defines the ultimate short-circuit breaking capacity (Icu), also known as the breaking capacity, according to a specified test sequence. This test sequence includes the verification of the overload release of the circuit breaker.
Switch-disconnectors and IEC/EN 60947-3
When switches, disconnectors, switch-disconnectors or fuse-combination units are included in a design, the IEC/EN 60947-3 standard is used. A switch-disconnector is capable of switching on and off a current under specified conditions. In the open position, the switch-disconnector provides an isolation function.
As the switch-disconnector is not equipped with an overcurrent release, it must be protected by an MCB, MCCB or fuse. The short-circuit capacity of the combination of switch and circuit breaker is defined as the rated conditional short-circuit current.
Low-voltage switchgear and IEC/EN 61439-1
IEC/EN 61439-1 applies to low-voltage switchgear and controlgear assemblies. For assemblies with an SCPD in the incoming unit, the manufacturer must indicate the maximum prospective short-circuit current at the input terminal of the assembly. To protect the assembly, the Icu or Icn of the SCPD must be equal to or higher than the prospective short-circuit current. If a circuit breaker with a time delay is used as an SCPD, or no SCPD is incorporated in the assembly, the Icw with the maximum time delay must be stated.
Tomi Engdahl says:
Why Circuit Breakers DON’T Protect People (electric shocks)
https://www.youtube.com/watch?v=gqEu9t8HwW0
Tomi Engdahl says:
https://www.facebook.com/share/p/t2bZj29W15xo9YBF/
Understanding different types of circuit breakers: A complete guide
- MCB (Miniature Circuit Breaker):
* Used for low current circuits in homes and offices.
* Protects against overcurrent and short circuits.
* Does not provide protection against earth faults.
- ELCB (Earth Leakage Circuit Breaker):
* Protects against earth faults by detecting leakage currents to the ground.
* Older technology, replaced mostly by RCCBs.
- RCCB (Residual Current Circuit Breaker):
* Modern version of ELCB.
* Detects and isolates leakage currents to protect against electric shocks and earth faults.
* Does not provide overcurrent protection.
- MCCB (Molded Case Circuit Breaker):
* Used for higher current applications than MCBs, typically in industrial settings.
* Provides protection against overloads, short circuits, and sometimes earth faults.
- ACB (Air Circuit Breaker):
* Used for high-voltage applications (up to 15 kV).
* Interrupts the arc in open air.
* Commonly used in industrial plants and power distribution systems.
- VCB (Vacuum Circuit Breaker):
* Suitable for medium and high-voltage applications.
* Uses a vacuum to extinguish the arc.
* Highly reliable, low maintenance, and long-lasting.
- MOCB (Minimum Oil Circuit Breaker):
* Uses a small amount of oil to extinguish the arc.
* Older technology, less commonly used today due to maintenance issues.
- BOCB (Bulk Oil Circuit Breaker):
* Uses a large volume of oil for arc quenching and insulation.
* Bulky and requires high maintenance; mostly replaced by modern breakers.
- SF₆CB (Sulfur Hexafluoride Circuit Breaker):
* Uses sulfur hexafluoride gas for arc quenching.
* Suitable for high-voltage applications.
* Highly efficient but more expensive and requires careful handling of SF₆ gas, which is a potent greenhouse gas.
- Summary:
* MCB and RCCB: Low-voltage and residential use.
* MCCB: Higher current and industrial use.
* ACB, VCB, and SF₆CB: Medium-to-high voltage and industrial or power grid applications.
* MOCB and BOCB: Older oil-based technologies.
* ELCB: Replaced by RCCB for earth leakage protection.