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FUJI ELECTRIC JOURNAL 2001 Vol.74-No.11
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Low-Voltage Switchgear apparatus relation |
Technical Trends of Low-Voltage Switchgear and Fuji Electric's Attitude
Akihiko Kohanawa
In the industry of low-voltage electrical facilities in Japan, the IEC standardization of equipment, devices, and technologies based on the WTO agreement on technical barriers to trade advances steadily. Low-voltage switchgear is also shifting to IEC standard products, centering around circuit breakers and magnetic switches. Concurrently, with recent progress in information technology, communication networks to monitor and control electrical equipment are being introduced. This paper outlines these technical trends and shows Fuji Electric s vision of future development, citing new low-voltage breakers conforming to IEC and an example of monitoring and control with LONWORKS/ AS- i open networks.
New Model Twin Circuit Breakers "
-TWIN Series"Nobuo Asahi, Kazuhiko Sato, Yoshiaki Kawashima
Fuji Electric has developed
- TWIN as new model twin breakers (molded-case circuit breakers and earth-leakage circuit breakers) for 100 A-frame or less. This model has integrated and modularized two series of circuit breakers for conventional distribution use and general-purpose circuit-protection use. In addition, the standard products satisfy the major standards, JIS, IEC and UL, and can be used internationally. This paper describes the distinguished features, specifications and structure of the- TWIN.
Constituent Technologies of "
-TWIN Series"Katsumi Watanabe, Akifumi Sato, Hisanobu Asano
In the development of the
- TWIN series (molded-case circuit breakers and earth-leakage circuit breakers) that has realized compact design and high internationality satisfying JIS, IEC and UL with standard products, it was required to strive for new technologies for the structure, materials and manufacturing. This paper describes some new technologies in developing the - TWIN series.
New Series of Electromagnetic Switches "SC-M/SC-E Series"
Shinobu Takeuchi, Masaaki Watanabe, Koetsu Takaya
As the JIS standard has been coordinated with the international standard, the requirements of electromagnetic switches have also been changed so as to realize the idea of safety typically represented by ISO12100 or to thoroughly pursue ecological measures and reduction in the size and number of wirings for control panels and machines. The newly developed mini-contactor SC-M and contactor SC-E series have the following features to meet the requirements: (1) direct terminal wiring possible (2) unified widths (3) protection-level IP20 construction for terminal fingers (4) arc space made free (5) mirror contact and linked contact functions provided.
Solid-State Contactor for Three-Phase Induction Motor Forward/Reverse Operation
Masahiro Motonobu, Toshiaki Miyano
The solid-state contactor(SSC) that has distinguished features such as long life, high-frequency switching, noiseless operation and freedom from maintenance is widely used for controlling various loads such as motors and heaters. To meet needs for reducing the space and wirings of machine control boards, Fuji Electric has developed a reversible SSC which enables on-off control of three-phase induction motor forward/reverse operation with one unit, adding a new line of switches. This paper gives an outline of the new solid-state contactor.
LONWORKS and AS-i Devices for Building and Facility Networks
Hideki Yamamizu, Noboru Kanzaki, Bunji Mori
In building automation and facility management, it has become an important subject to reduce the total cost for the system development to maintenance by structuring a total system based on an open network. The LONWORKS and AS-i bus regarded as networks suitable to this need have already diffused in Europe and USA, and are supposed to expand rapidly also in Japan in future. This paper describes their features and available devices from Fuji Electric.
Energy Saving Support and Energy Monitoring Devices "F-MPC Series"
Shunsuke Shikano, Tsuneo Kiuchi, Hiroshi Sato
Increase in greenhouse gases typically represented by carbon dioxide in the atmosphere has caused global warming, and countermeasures should urgently be taken on an international scale. One of realistic countermeasures is the promotion of energy saving, and every country is required to make efforts at its maximum. Now energy saving is in the times of action out of publicity. This paper describes onsite measuring devices, simple energy-saving monitors, and software packages for power monitor systems using a general-purpose personal computer to be used in supporting energy saving.
High-Speed Current-Limiting Circuit Breaking Equipment for 6kV Power System
Takeshi Okamura, Nobuo Suzuki, Hisashi Nojiri
Fuji Electric has developed a high-speed current-limiting circuit breaking equipment to protect important equipment in a cogeneration system from a commercial power system fault. The main components of this equipment are a high-speed vacuum circuit breaker, capacitors to supply high-frequency current for superposition to make current zero, nonlinear resistors to suppress overvoltage, and a high-speed power fault detector. This equipment can limit fault current and reduce instantaneous voltage drop duration.
