3AH4 — vacuum circuit breakers for frequent switching and arc furnaces up to 40.5 kV (up to 120,000 operations)
A family of medium-voltage vacuum circuit breakers for a very high number of switching operations, in two versions. The frequent-switching version is rated for 24 kV and 3150 A, the arc-furnace version for 40.5 kV and 4000 A. Endurance reaches 90,000 and 120,000 operations respectively.
- 3AH4 for frequent operations
- up to 24 kV; up to 40 kA; up to 3150 A; 45,000 operations without maintenance, up to 90,000 in total
- 3AH4 for arc furnaces
- up to 40.5 kV; up to 40 kA; up to 4000 A; up to 120,000 operations
- Furnaces
- small and medium up to 200 MVA; parallel arrangements for large ones
- Technology
- vacuum interrupters, modular 3AH platform
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
3AH4 is built on the modular 3AH circuit-breaker platform with the manufacturer's own vacuum interrupters. The family comes in two versions aimed at different tasks.
3AH4 for frequent operations is intended for installations where the breaker switches the load many times a day: drives with frequent starts, capacitor banks, process applications. Rated voltage is up to 24 kV, breaking current up to 40 kA, rated current up to 3150 A. Vacuum technology allows up to 45,000 switching operations without maintenance; after scheduled servicing the breaker regains its characteristics for another 45,000 operations, so total endurance is 90,000 operations. Clear service intervals simplify planning, and a lower demand for spare parts reduces operating costs.
3AH4 for arc furnaces is designed for metallurgy, where a furnace performs more than 100 switching operations per day and requires both a high switching frequency and high power. Rated voltage is up to 40.5 kV, breaking current up to 40 kA, rated current up to 4000 A, endurance up to 120,000 operations with simple maintenance. The breaker suits small and medium arc furnaces up to 200 MVA; for larger installations, modular parallel arrangements are used, which keep operation stable at increased ratings.
Both versions are configured with an online configurator. Applications include furnace transformers of electric steel and ferroalloy furnaces, ladle furnaces, electric drives of pumps and compressors with frequent starts, switching of capacitor banks and higher-harmonic filters, and test stands.
Technical specifications
| 3AH4 for frequent operations | up to 24 kV; up to 40 kA; up to 3150 A; 45,000 operations without maintenance, up to 90,000 in total |
|---|---|
| 3AH4 for arc furnaces | up to 40.5 kV; up to 40 kA; up to 4000 A; up to 120,000 operations |
| Furnaces | small and medium up to 200 MVA; parallel arrangements for large ones |
| Technology | vacuum interrupters, modular 3AH platform |
Request a price and lead time
3AH4 — vacuum circuit breakers for frequent switching and arc furnaces up to 40.5 kV (up to 120,000 operations). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What endurance does the frequent-switching breaker have?
Up to 45,000 operations without maintenance, and another 45,000 after scheduled servicing, i.e. up to 90,000 operations in total.
What voltage and current is the arc-furnace version rated for?
Voltage up to 40.5 kV, breaking current up to 40 kA and rated current up to 4000 A, with endurance up to 120,000 operations.
Which furnaces is the breaker suitable for?
Small and medium arc furnaces up to 200 MVA. For larger installations, parallel arrangements are used.
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