Prepäťová ochrana HiSmart NV821709 3-pólová, 30–60 kA, 385 VAC

HiSmart NV821709 is a 3‑pole surge protection device rated for 385 VAC designed to protect electrical installations and connected equipment from transient overvoltages. Installed on a 35 mm DIN rail in the building's incoming low-voltage distribution box, the device diverts surge energy to ground and is suitable for TT, IT, TN‑S, TN‑C and TN‑C‑S systems. It meets international standards including IEC 61643-1 and carries CE marking.

Advantages

The unit provides Class B protection with a nominal discharge current of 30 kA and a maximum discharge current up to 60 kA, offering a fast response time of less than 25 ns. With a maximum continuous operating voltage of 385 V AC and a voltage protection level ≤ 2.2 kV, it supports three‑phase protection while occupying minimal panel space (54 × 90 × 67 mm). The device is rated for wide operating temperatures (-40 °C to +85 °C) and accepts conductor cross‑sections up to 6–10 mm².

Suitable for

• Incoming line protection in residential distribution boards
• Protection for commercial and light‑industrial three‑phase panels
• Systems using TT, IT, TN‑S, TN‑C or TN‑C‑S earthing configurations

Key specifications

• Poles: 3
• Class: B
• Maximum continuous operating voltage (Uc): 385 V AC
• Nominal discharge current (In): 30 kA
• Maximum discharge current (Imax): 60 kA
• Voltage protection level (Up): ≤ 2.2 kV
• Response time: < 25 ns
• Frequency: 50/60 Hz
• Operating temperature: -40 °C to +85 °C
• Relative humidity (at 25 °C): < 95%
• Mounting: 35 mm DIN rail
• Wire cross‑section: up to 6–10 mm²
• Dimensions: 54 × 90 × 67 mm
• Standards: IEC 61643-1, GB18802.1, GB50057, CE

How to use

Install the HiSmart NV821709 on a standard 35 mm DIN rail inside the building's main low‑voltage distribution box, connecting the three phase conductors and the protective earth according to local wiring rules and the panel schematic. Ensure the device is placed at the incoming line position for primary protection and that connections are tightened to the manufacturer's torque recommendations. Verify compatibility with the earthing system (TT, IT, TN‑S, TN‑C or TN‑C‑S) before energizing the installation.

Recommendations

Check the device periodically and after known surge events; replace the unit if internal indicators (if present) show it is spent. Maintain clear labeling in the distribution board and follow applicable national electrical codes for installation and grounding.