Air Circuit Breakers (ACB), Molded Case Circuit Breakers (MCCB)

 

 

 

Protecting electrical equipment against damage

The number of electrical consumers continues to grow – and along with them the load on electrical systems. In the event of overload or a short-circuit, miniature circuit breakers (MCBs) safely cut the connected circuit and thus reliably protect electrical systems and devices against damage. Miniature circuit breakers (MCBs) in the SENTRON portfolio are also easy to assemble and install. The devices feature a uniform design, and can be expanded to include many more functions thanks to an extensive range of accessories. For industries, buildings or infrastructure – our extensive portfolio has the right MCB for every application.

Miniature circuit breakers for all applications

Miniature circuit breakers protect electrical systems against overload and short circuits. With tripping characteristics A, B, C and D, all fields of application in industry, residential and non-residential buildings are covered. The special design of the terminals in Siemens devices also ensures highly-effective touch protection.

A comprehensive portfolio

Siemens offers a complete range of miniature circuit breakers from 0.3 to 125 A in all required A, B, C and D characteristics. This means that all applications are covered.

Maximum conductor protection

With miniature circuit breakers from Siemens, you can expect the highest quality and reliability. The excellent technical properties of the devices mean you are always on the safe side. Apart from that you benefit from the innovative mounting options which enable quick and easy installation

Wide range of additional components and accessories

The miniature circuit breakers from Siemens can be combined as required with a wide range of supplementary components e.g. control current switches, fault signal contacts, shunt releases, undervoltage releases, remote operating mechanisms or with RCCB units to provide protection for persons and against fire.

Earth-leakage Circuit Breakers (ELCB)

อุปกรณ์ป้องกันไฟรั่วไฟดูดคุณภาพสูงสามารถป้องกันอันตรายอันเกิดจากไฟฟ้าดูดจากการสัมผัสโลหะเปลือกนอกของเครื่องใช้ไฟฟ้าที่ขัดข้องเมื่อกระแสรั่วเพียง 30mA

An ELCB ((earth leakage circuit breaker) and an RCCB (residual current circuit breaker) both have similar purposes, in that they are intended to trip when the current is not confined to the current carrying conductors. Another name used is current balance circuit breaker. These are all used with grounded power supplies.

The original use was for larger motors and generators/transformers, where the insulation can fail, and the voltage on the frame of the machine can rise dangerously above ground due to the ground resistance and fault current.

An ELCB had a current sensing coil in series with the ground cable, so the supply would be tripped if current occurred in the ground lead. This was often combined with a voltage sensing coil on the frame also, which used a separated ground some distance away.

The RCCB senses the balance of the go and return current in the current carrying conductors and trips the supply if the current is different. The current in the supply cables is different because some is returning via ground. The main purpose is to provide additional protection against electric shock when someone touches an active conductor.

These devices trip with only a few milliamps of current imbalance and within a specified time period, so that in theory the supply is removed before someone contacting active wires can receive a dangerous shock.

These terms have become more or less interchangeable now, in the domestic situation at least, though it could be that a true ELCB is obsolete except for specialised situations.

                How they work and a drawing? The earlier designs used magnetic components, though modern devices may be magnetic (a specialised relay) or electronic. If you search for "How it works RCCD" you should find some simplified diagrams of the magnetic types. The electronic type may use a transformer with a current winding for go and a current winding for return, so the two currents cancel. A third winding detects the voltage produced when they are not balanced. There is no point making your own, as the testing and certification is rigorous if you are required to have them by regulations.

Arrester Combinations

อุปกรณ์ป้องกันฟ้าผ่า โดยจะถ่ายเทไฟฟ้ากระชากที่เกิดจากฟ้าผ่าลงสู่ดิน

Surge arresters

Siemens has been designing and manufacturing medium- and high-voltage surge arresters for standard and special applications since 1925. Continuous research and development, the wealth of Siemens know-how, and comprehensive worldwide experience give Siemens surge arresters a leading edge in overvoltage protection. Their uncompromising quality ensures a long service life and reliability in any application. Valuable equipment such as transformers, circuit breakers, generators, motors, capacitors, traction vehicles, and bushings, as well as complete switchgear, is ideally protected against lightning and switching over voltages.

·         High-voltage station arresters for applications up to 1200 kV. For the protection of substation equipment.

·         Medium-voltage arresters for distribution networks: Medium-voltage distribution arresters for applications up

          to 72.5 kV. For the protection of distribution networks and components.

·         Monitoring devices

·         A full range of monitoring solutions for surge arresters.

·         Line surge arresters (NGLA / EGLA): Line surge arresters for overhead power lines for up to 800 kV.

  Catalog 2021