The new 8365-F circuit breaker
Advantages of switching to DC
Switching to DC voltages offers several technical advantages. A key aspect is the improved integration of renewable energy sources, as photovoltaic systems and battery storage already supply direct current. Complex conversion measures can be reduced, which increases efficiency and system performance.
Batteries and uninterruptible power supplies (UPS) can be integrated more easily into DC networks as buffer systems. Furthermore, for the same electrical power, the current decreases as the voltage increases. This results in lower resistive losses orallows the use of cables and conductors with smaller cross-sections. This is a crucial factor, specifically in applications where space is limited.
Higher DC voltages in telecommunications and data centres
These benefits are particularly relevant for telecommunications systems and data centres, where power consumption rises steadily with each new generation of electronic chips. The forecast for the development of performance data over the next five years assumes up to 1 MW per server rack. Conventional AC architectures are increasingly reaching their limits in terms of efficiency and scalability. HVDC concepts are therefore becoming a realistic alternative.
8365-F circuit breaker for DC 400 V
The 8365-F is the first circuit breaker in E-T-A’s new 8365 series of circuit breakers available for 400 V DC. Thanks to the high rated voltage, it is no longer necessary to connect several circuit breakers in series, saving both space and cost.
The circuit breaker is available in a single-pole and double-pole version with hydraulic-magnetic tripping and features a rocker-arm actuator, screw- and plug-in mounting options, different trip characteristics, and optional auxiliary contacts for signalling the switching status.
The hydraulic-magnetic trip principle ensures that the trip behaviour is virtually independent of the ambient temperature. Compared to circuit breakers with thermal or thermal-magnetic tripping, power loss is at a minimum. The precise switching mechanism ensures reliable disconnection through an independent trip-free mechanism even at the smallest overcurrents.
A key advantage of the 8365-F is its suitability for modular systems. Design engineers can integrate it into existing or new power distribution systems without compromising on space requirements or complicating maintenance. This helps with scaling systems and adapting them to project-specific requirements.
Application in the HVDC Power-D-Box from E-T-A
The new E-T-A HVDC (High Voltage DC) Power-D-Box is a compact power distribution system for DC 400 V, equipped with the 8365-F to protect the connected loads. Typical areas of application include telecommunications, data centres and network infrastructures.
The system is designed in two height units, has a redundant configuration and can accommodate up to eight pluggable, double-pole 8365-F circuit breakers. The circuit breakers reliably disconnect all poles in the event of faults in the positive and negative circuits. The power supply and group signalling are fully integrated into a finger-safe plastic housing. Mechanically coded connectors for the power supply and arc-suppressing connectors at the load outputs ensure a high level of safety. The HVDC Power-D-Box is designed for systems with current limiting power supply units (PSUs) and can be adjusted to specific application requirementsthanks to its modular design.
