Technical Specification: 9kV / 5kA Surge Protective Devices
Surge Protective Devices (SPDs)—often called lightning arresters—are key for protecting electrical systems. They guard against sudden, short-term voltage spikes. These spikes can come from lightning strikes, whether direct or indirect, or from switching equipment on and off. A 9kV / 5kA SPD is built to offer strong protection. It works well in industrial and commercial power distribution systems.
Key Specifications Explained:
9kV Maximum Continuous Operating Voltage (MCOV or Uc) is the highest RMS voltage the SPD can handle nonstop across its terminals—like Line-to-Line, Line-to-Neutral, or Line-to-Ground. It won’t break down or turn on by accident. A 9kV MCOV means it works well with systems that have higher normal voltages and can put up with temporary overvoltages (TOVs). You’ll often find it in 480VAC 3-phase systems, where Line-to-Line voltages hit 480V RMS. It also fits in distribution panels after service entrance SPDs and in places where voltages change a lot.
5kA Nominal Discharge Current (In) is the peak of a standard 8/20 µs current wave. The SPD must discharge this at least 15 times without getting damaged, following IEC 61643-11. A 5kA In rating shows it can handle medium to high surge currents. These SPDs are Type 2 (Class II) devices. They protect against surges that come from upstream SPDs or start inside a building, dealing with most of the leftover surge energy.
Technology & Operation:
The core component in most 9kV/5kA SPDs is the Metal Oxide Varistor (MOV). MOVs show high resistance at normal operating voltages. When voltage exceeds the MOV’s threshold, its resistance drops sharply, creating a low-impedance path to divert surge current safely to ground.
Engineers design these SPDs for parallel connection across the protected power conductors.
Critical Performance Parameters:
Voltage Protection Level (Up) is the highest voltage seen across the SPD’s terminals when it discharges the 5kA In current. A lower Up means better protection for the equipment downstream.
MOV-based SPDs have a fast response time—nanoseconds. They clamp down on surges before they can damage equipment.
These SPDs also have thermal protection, a fail-safe feature. If an MOV overheats and starts to degrade, built-in thermal disconnectors cut it off from the circuit. This stops fire risks and keeps power flowing, often with a visible sign that something’s wrong.
Good SPDs follow standards like IEC 61643-11, UL 1449 5th Edition, or others like them. This ensures their performance and safety are proven.
They are mainly put in distribution panels, sub-panels, or critical load panels. You’ll find them in places using 480VAC 3-phase systems or similar higher voltage setups. They protect switchgear, PLCs, motor drives, and other important equipment.
Summary:
The Abimat 9kV / 5kA SPD is a key Type 2 protection part for tough electrical environments. It has a 9kV MCOV, which keeps it working steadily—even when line voltages are normal or changing. Its 5kA In rating gives it plenty of capacity. It can repeatedly redirect harmful surge currents, whether from lightning or switching, away from the system.
This SPD clamps overvoltages down to a safe level (Up). It also sends surge energy into the ground. Doing this protects industrial and commercial electrical setups, as well as sensitive equipment downstream. When choosing one, you need to think about the system’s specific voltage, the required Up, and the relevant safety standards.
