Voltage surges damage equipment, disrupt operations, and cause costly downtime. LEEYEE offers high-performance SPDs with superior discharge capacity to protect industrial and solar power systems.
A Surge Protective Device (SPD) is an electrical safety device that limits transient overvoltage by diverting surge current to the ground. It protects equipment from lightning strikes, switching surges, and other disturbances. SPDs are essential in industrial, commercial, and photovoltaic (PV) systems where sensitive electronics demand reliable surge protection.
Now, let’s explore how SPDs work, their types, importance, and where they are most crucial.
How do SPDs work?
A Surge Protective Device functions by detecting transient overvoltage and providing a low-impedance path to redirect excess energy safely to the ground. Normally, the SPD remains inactive, allowing normal voltage to pass. However, when the voltage exceeds its threshold—known as the “let-through voltage” or Voltage Protection Level (Up)—its internal components such as Metal Oxide Varistors (MOVs) or gas discharge tubes, conduct, shunting the surge energy away from sensitive loads. The response time is critical; high-quality SPDs like those from LEEYEE react in less than 25 nanoseconds, ensuring equipment remains unharmed even during fast, high-energy spikes caused by lightning or switching events.
Types of SPDs
SPDs are classified by installation location and surge handling capacity:
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Type 1 SPD – Installed at the service entrance; designed to withstand direct lightning currents (10/350μs waveform).
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Type 2 SPD – Installed in sub-distribution panels; protects against residual surges (8/20μs waveform) from switching events or nearby lightning.
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Type 3 SPD – Installed close to sensitive equipment; provides fine protection for devices like servers or PLCs.
LEEYEE manufactures AC and DC SPDs for both low-voltage power distribution and PV systems, with nominal discharge currents (In) from 5kA to 20kA and maximum discharge currents (Imax) up to 100kA—among the highest in China’s industry.
Importance of SPDs
SPDs are critical for maintaining operational continuity and equipment longevity. Transient surges, even those below visible damage thresholds, can degrade insulation and semiconductor junctions over time, leading to premature failures. In industries such as telecommunications, data centers, and renewable energy, even milliseconds of downtime can result in significant financial losses. The IEC 61643-11 standard mandates SPD use in many high-risk installations. LEEYEE’s SPDs, certified by CE, TUV, CB, and ISO9001, meet global compliance requirements, ensuring both safety and regulatory adherence.
SPDs are crucial for:
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Power distribution systems – Protect transformers, breakers, and downstream equipment from lightning and switching surges.
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Photovoltaic systems – Safeguard solar panels and inverters from DC surges caused by nearby strikes.
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Industrial automation – Prevent PLCs, drives, and sensors from malfunctioning during grid disturbances.
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Data centers – Ensure uninterrupted service by protecting servers and network switches.
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EV charging stations – Shield sensitive charging electronics from grid instability.
By integrating SPDs, engineers significantly reduce maintenance costs and extend asset service life.
Examples of SPDs
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LEEYEE LY1-PV – DC SPD for PV arrays, Up < 2.5kV, In 20kA, Imax 40kA, response time <25ns.
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LEEYEE LY1-AC – AC SPD for distribution boards, Up < 1.8kV, In 20kA, Imax 60kA.
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LEEYEE Modular SPD – Pluggable module design for quick replacement without rewiring.
These models are widely used in substations, industrial control cabinets, solar farms, and military installations. With an 8,000m² factory, LEEYEE supports OEM/ODM customization to meet diverse application requirements.
SPDs are essential to safeguard modern electrical systems from surge electric events, ensuring safety, reliability, and operational efficiency.
FAQs: Surge Electric
Q1: What is surge electric?
A surge electric event is a sudden voltage increase that can damage electrical equipment.
Q2: How does a Surge Protective Device help?
It redirects excess voltage to ground, protecting equipment from overvoltage damage.
Q3: Are SPDs only for industrial use?
No. They are used in residential, commercial, and renewable energy systems.
Q4: How often should SPDs be inspected?
At least annually or after major surge events.
Q5: Do SPDs stop long-term overvoltage?
No. They are designed for transient events. Use under- or over-voltage protectors for sustained issues.
Disclaimer:
This content is for informational purposes only. Consult a licensed electrical engineer for site-specific surge protection design.