We receive frequent inquiries about matching selection of three core 10kV pole-mounted devices: GW9 series disconnector, YY-10 drop-out fuse and HY5WS drop-type surge arrester from project purchasers and construction teams. Here we summarize practical selection experience based on years of bulk supply service.
GW9-12 outdoor high voltage disconnector fits 10kV,12kV and15kV distribution circuits. Rated current is the first selection index: 200A matches small transformers from 50kVA to160kVA; 400A and 630A are for large-capacity transformers and main trunk lines. For coastal or chemical industrial areas with heavy pollution, silicone rubber insulated type is recommended for better anti-pollution and anti-corrosion performance instead of traditional porcelain insulator. Important reminder: disconnector is only for off-load isolation and cannot break loaded current.
As standard protection for 10kV distribution transformers, YY-10 drop-out fuse needs matched fuse link according to transformer capacity: 10A for 50kVA transformer, 16A or20A for 100kVA transformer. The fuse tube drops down automatically after short-circuit or overload breakdown with visible breaking point for easy maintenance and fuse replacement.
HY5WS-17/50DL-TB integrated drop-type surge arrester is the preferred lightning protection choice for outdoor transformers. It will fall off automatically once internal breakdown occurs to avoid earth fault of whole lines, greatly cutting maintenance cost especially for thunder-prone mountain areas, PV and wind power stations.
The most widely used collocation in domestic power industry: install disconnector, drop-out fuse and drop arrester from top to bottom on transformer high-voltage terminal, which is standard configuration for rural power grid and industrial outdoor distribution projects.
Besides electrical parameter confirmation, buyers should check official type test reports before purchase. Yueyang Electric manufactures all three types of products and can customize specifications to adapt different regional climate and project requirements.