Surge Protective Device: Designed to Protect EV Chargers
With integrated Surge Protective Device (SPD) protection, you can safeguard both charging stations and electric vehicles against damaging voltage surges caused by lightning strikes or grid switching operations. We offer a versatile range of protective devices designed for a comprehensive safety concept, ensuring your charging infrastructure remains operational 24/7—regardless of weather conditions.
SD20R Series Technical Specifications
SET Models | LV Systems |
Mode | Uc(VDC) | In(kA) | Imax(kA) | UP(kV) | IPE(mA) | Schematic |
SD20R24L211DC | DC | DC+/- -PE | 600 | 20 | 40 | 0.4 | 1.0 | Fig 1 |
SD20R240L211DC | DC | DC+/- -PE | 600 | 20 | 40 | 1.0 | 1.0 | Fig 1 |
SD20R600L211DC | DC | DC+/- -PE | 600 | 20 | 40 | 2.0 | 1.0 | Fig 1 |
SD20R600L312 DC | DC | DC+/- -PE, DC+ -DC- | 600 | 20 | 40 | 2.4 | 1.0 | Fig 2 |
SD20R800L312 DC | DC | DC+/- -PE, DC+ -DC- | 800 | 20 | 40 | 3.2 | 1.0 | Fig 2 |
SD20R1000L312 DC | DC | DC+/- -PE, DC+ -DC- | 1000 | 20 | 40 | 3.6 | 1.0 | Fig 2 |
SD20R1200L312 DC | DC | DC+/- -PE, DC+ -DC- | 1200 | 20 | 40 | 4.2 | 1.0 | Fig 2 |
SD20R1500L312 DC | DC | DC+/- -PE, DC+ -DC- | 1500 | 20 | 40 | 5.0 | 1.0 | Fig 2 |
Schematics
Application Examples
Dimensions (mm)
Remark：this is a 3P structure product dimensions, which width size is 54mm; for 1P, 2P or 3P structures, the width size is 1, 2 or 3 times of 18 mm.
Recommended installation methods
Remarks: SPD must be checked for external damage before installation. If any damage or other faults are detected in this check, SPD must not be installed.
Informative
The IEC 61643-41:2025 standard introduces several major differences compared with the existing PV surge protection standard. Key distinctions include:
Higher short-circuit current requirements
Different supply and protection configurations, such as midpoint, grounded, and isolated systems
More stringent Temporary Overvoltage (TOV) requirements, including worst-case scenarios where the SPD may be exposed to double the rated voltage
This new DC surge protection standard is essential because conventional power SPDs—whether compliant with IEC 61643-31 (DC PV SPDs) or IEC 61643-11 (AC SPDs)—do not fully address the unique risks and operating conditions found in general DC applications.
BESSUN’s DC surge protection products are specifically designed for a wide range of general DC applications, including industrial equipment (robotic arms and motor drives), EV fast charging systems, battery energy storage systems (BESS), control cabinet supply lines, safety lighting, and other DC-powered loads. By enabling direct DC protection, these solutions help eliminate unnecessary AC/DC conversions, improving overall system efficiency and reliability.
Compared with PV systems, general DC applications often present significantly higher short-circuit currents, either due to the upstream AC grid or the high fault current capability of batteries. To ensure safe operation under fault conditions, most new DC SPDs are designed to operate with an external overcurrent protection device, which acts as a disconnector in the event of SPD failure.
In addition, UL 1449, 5th Edition allows SPDs to be certified specifically for PV or general DC applications. Testing requirements for DC SPDs are defined in Supplement SB, which imposes more stringent end-of-life disconnection criteria than those applied to PV SPDs. BESSUN’s latest DC surge protection products are fully UL certified under these requirements, ensuring compliance with global safety and performance standards.
