DC SPD OEM

Understanding purpose
Solar DC SPDs are designed to protect solar panels and associated equipment from power / solar surges and transient spikes. Shunts excess voltage to ground to protect the system from damage. Familiarize yourself with the importance of solar surge protection in your photovoltaic system.
Compliance and certification
Make sure the DC SPD you choose meets relevant industry standards and certifications. Look for certifications that ensure your device meets specific safety and performance standards.
Voltage value
The maximum continuous operating voltage Uc PV of the photovoltaic system: usually DC 500V 600V 800V 1000V 1200V 1500V. Determine the maximum nominal voltage required for the photovoltaic system. It should match or exceed the maximum voltage that the panel will produce. Residential systems are typically rated at 1000 V or less, but commercial or public systems may require a higher voltage rating. Hence a DC SPD 1000V can be applied.
Surge current rating
Maximum discharge current Imax: usually Imax: 10kA, 20kA, 40kA, 60kA, according to the use in different occasions. Consider surge current ratings. This indicates the maximum amount of current the DC SPD can handle during a surge event. It should be enough to handle potential surges in the system. Power ratings are usually expressed in kiloamperes (kA).
SPD type
Various types of DC SPDs are available, such as Type 1, Type 2 and Type 3. Type 1 SPD is installed at the main inlet of the power supply to provide comprehensive protection. Type 2 DC SPDs are typically installed in sub-distribution boxes or junction boxes to provide protection against overvoltages from outside the building. Type 3 DC SPDs provide device-level local protection.
Voltage protection level (Vp)
VPL is a measure of how effectively a DC SPD limits transient voltages. This represents the voltage level at which the solar surge protection device limits transient voltages. Choose a DC SPD with a lower VPL as it provides better protection for your system.
Warranty and lifetime
Be aware of DC SPD’ s manufacturer’ s warranty. A long warranty usually reflects confidence in the quality of the product. Also, check the life expectancy of your DC SPD to make sure it matches the life of your PV system.

Inter-cloud and intra-cloud lightning flashes with magnitudes of 100kA can create related magnetic fields that trigger transient currents in PV system DC cabling. These transient voltages arise at equipment terminals and trigger important component insulation and dielectric failures. These generated, and incomplete lightning currents are mitigated by placing DC SPDs at specific locations. The DC SPD is connected to the ground in parallel with the electrified wires. When an overvoltage occurs, it switches from a high-impedance to a low-impedance device. The DC SPD discharges the related transient current in this design, reducing the overvoltage that would otherwise exist at the equipment terminals. This parallel device carries a no-load current. The DC SPD you choose must be designed, rated, and approved, particularly with DC PV voltages. The inherent DC SPD disconnect must be capable of interrupting the more severe DC arc that is not present in AC applications.

On large commercial and utility-scale PV systems operating at a maximum open-circuit voltage of 600 or 1,000V DC, connecting MOV modules in a Y configuration is a popular DC SPD setup. A MOV module is linked to each pole and ground on each leg of the Y. There are two modules between each pole and both pole and base in an ungrounded system. Because each module is rated for half the system voltage in this configuration, the MOV modules do not exceed their rated value even if a pole-to-ground failure occurs.

Place the SDP as close to the panel to be protected as feasible. To decrease the length of the connecting wires from the surge protective device’ s lugs to the next panel’ s circuit breaker, drill and punch a hole in the surge protective device housing in an extraordinarily high place (or fused disconnect lugs). Use a close-nippled connection with wires traveling to the first breaker at the top of a panel whenever possible. This guarantees that all loads connected to the panel are adequately protected. Connect the DC SPD to the breaker panel with stranded wire or bigger (readily available and easy to install). In the wiring, avoid sharp bends and excessive length. The most successful installations aren’ t usually the most aesthetically pleasing. The most effective encounters are short and direct. DC SPDs should be connected to a properly rated circuit breaker rather than the panel’ s main lugs. A fused disconnect switch should be used to communicate with the lines and facilitate DC SPD servicing where circuit breakers are unavailable or impractical.