DC Surge Protective Device

We strongly recommend using a dedicated SCB.Standard breakers cannot distinguish between lightning currents (which need to pass) and power frequency follow currents (which need to be cut off), leading to nuisance tripping or failure to clear faults. SCBs are designed specifically for SPD characteristics, offering higher safety.

The voltage protection level (Up) should be selected based on the withstand voltage rating of the equipment to be protected. Suntree products cover various Up values: Up≤2.8kV for 500VDC systems, Up≤3.6-4.0kV for 1000VDC systems, and Up≤5.0kV for 1500VDC systems. The general principle is to select an SPD with Up lower than the withstand voltage rating of the protected equipment.

The selection is based on the rated DC voltage of the PV system. 600V SPD is suitable for small residential systems; 1000V SPD is suitable for commercial rooftop systems; 1500V SPD is suitable for large-scale ground-mounted power plants. The 1500V system is currently the mainstream configuration for large power plants, effectively reducing line losses and system costs.

The continuous operating voltage (Uc) should be greater than or equal to the maximum continuous operating voltage of the PV system. Suntree DC SPDs offer various Uc options: 48-500V, 600V, 800V, 1000V, 1200V, and 1500VDC. It is recommended that Uc be at least 1.2 times the system open circuit voltage (Uoc) to ensure the SPD does not fail within the normal voltage fluctuation range.

Suntree SPD features two failure indication methods: window indication and remote signaling. Window indication: green indicates normal operation, red indicates replacement required. Remote signaling: optional floating changeover contact available for connection to monitoring systems for remote status monitoring.

T1 is mainly for outdoor distribution box,T2 is mainly for indoor distribution box, T1+T2 means that it is suitable for indoor + outdoor.