The type of SPD (Storage Damper) is selected according to the installation location and lightning risk: Type 1 (or Type 1+2) for service entrances with direct lightning risk (LPS or overhead line), Type 2 if there is no risk; Type 2 in intermediate panels; Type 3 near sensitive equipment. The final choice is based on the TS EN 62305 risk analysis.

Service entrance + lightning risk → Type 1 · Intermediate panel → Type 2 · Equipment → Type 3
Example calculation: Service inlet + LPS/overhead line risk → Type 1 (or Type 1+2 combined), Iimp (10/350 µs) specified; 3+1 connection arrangement in TT system.

SPD / Surge Arrester Selection Guide

Determine the appropriate type of surge protector (SPD) based on the installation location, lightning risk, and grounding system.

Notes: This is an election guide; The final SPD selection is made according to the TS EN 61643 and TS EN 62305-2 risk analysis standards. The Up (protection level) must be below the surge withstand capability of the equipment to be protected, and the backup fuse should be selected according to the manufacturer's data. The surge arrester is connected with a conductor length not exceeding 0.5 m (V connection).
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How is it calculated?

  1. Select the installation location (service entrance / intermediate panel / next to equipment).
  2. Select lightning risk (LPS/overhead line or no risk).
  3. Select system grounding and press Suggest.

Frequently Asked Questions

What is the difference between Type 1 and Type 2 SPD?
Type 1 carries direct lightning current (10/350 µs); required at service entrances where there is risk of LPS or overhead lines. Type 2 protects against indirect overvoltages (8/20 µs).
When is Type 3 needed?
As additional protection, in coordination with Type 2, next to sensitive equipment located away from the main panel (>10 m).
What else is important in the SPD election?
The Up (protection level) of the equipment must be below the impact resistance level, and the backup fuse and connection length (≤0.5 m) should be selected according to the manufacturer's data.

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This tool and its content are for general informational purposes only; they do not constitute a binding inspection/declaration of conformity. Definitive results will be determined through on-site inspection in accordance with relevant legislation and standards. Get a quote →