SYW6GZ-4000 DC Switch-Disconnector and Fuse-Combination Unit for a BESS Project in Poland

The project adopts a DC 1500 V system and requires reliable DC switching equipment with a compact footprint, efficient installation and convenient maintenance. The solution also needs to meet relevant international certification requirements for the overseas BESS application while supporting efficient combiner cabinet integration.

• System cost — Conventional separate disconnector and fuse configurations require additional copper busbars, support brackets and fasteners, increasing material and cabinet assembly requirements.
• Limited cabinet space — Conventional 4-pole DC switches require more cabinet space and copper busbar connections, making compact combiner cabinet integration more difficult.
• Installation and maintenance — Separate components involve additional installation steps, while fuse replacement may require partial cabinet disassembly, increasing site maintenance workload.
• Compliance and reliability — The equipment requires relevant international certifications, reliable arc interruption and mechanical endurance for BESS operation.

Sieyuan supplied the SYW6GZ-4000 DC switch-disconnector and fuse-combination unit with bilateral fuses as the core DC power distribution device. The integrated design combines the disconnector and fuse in one unit, reducing the number of auxiliary components and simplifying cabinet integration. Rated at DC 1500 V and 4000 A, the product supports front-access fuse replacement and holds CCC, CE, TUV, AS and UL certifications.

• Integrated design — Eliminates the need for more than seven categories of auxiliary components, including copper busbars, support brackets and fasteners. Fuse signal circuits are integrated into the secondary terminals.
• Compact 2-pole structure — The side-by-side arrangement of the disconnector and fuse reduces copper busbar consumption by approximately 10 kg per unit. Product volume is reduced by up to 62.9% compared with conventional 4-pole switches.
• Front-access maintenance — A single fuse can be replaced from the front in less than 10 minutes, without dismantling surrounding cabinet components.
• Installation efficiency — The optimized mechanical design improves on-site installation efficiency by more than 40% and component replacement efficiency by more than 80%.
• Mechanical endurance — The arc chamber uses a tube-constriction structure and copper-tungsten alloy contacts. The product has undergone high- and low-temperature tests and 15,000-cycle mechanical endurance verification. The 2-pole design requires approximately half the mechanical energy of a comparable 4-pole design.