SPD is an electronic device that protects electronic equipment, instruments, and communication connections against unauthorized access. SPD can conduct the shunt in a very short time when the peak current or voltage is rapidly generated in the electrical circuit or communication line owing to external interference, preventing surge damage to other equipment in the circuit.
DC SPD is ideal for AC 50/60Hz power supply systems with a rated voltage of 220 V to 380 V, and can be used to protect against indirect and direct lightning strikes, as well as other types of sudden overvoltage surges, in the home, tertiary industry, and industrial settings.
Considerations for DC Surge Protection Devices in PV Installations
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 SPDs at specific locations. The 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 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 SPD you choose must be designed, rated, and approved, particularly with DC PV voltages. The inherent 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 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.
How to install a DC Surge Protection Device
- 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 SPD to the breaker panel with AWG #10 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.
- 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 SPD servicing where circuit breakers are unavailable or impractical.
DC Surge Protection Device general characteristics
- High pass flow, high safety performance, high working voltages, and high stability,
- No after flow and built-in temperature control circuit technology,
- Meets high altitude area requirements, has high withstand voltage, safe ultra-wide electrical spacing, and creepage distance,
- Can be equipped with remote monitoring interface, which can be used for monitoring remotely,
- Easy to maintain due to its plug and pull design, charging replacement, and no load current consideration,
- Easy and clear to distinguish as the device indicates that the green color of the window means success and the red shows the failure.
How to apply the DC SPD
SPD safeguards the leading electricity network’s lightning power supply system from an excessively high voltage or voltage surge caused by direct current (DC). Disconnecting switches, a circuit breaker, the surge protecting device (SPD), and an overload relay box are all part of the SPD.
In addition, these surge protectors are a cost-effective approach to limit apparatus damage caused by transients and surges in power and signal lines, as well as to save downtime, boost system, and data reliability, and reduce downtime caused by transients and surges in power and signal lines.
Any facility or load can benefit from the surge protection device (1000 volts and below). Surge arresters can be used everywhere, from a home to a utility substation, and they have a wide range of applications. Circuit breakers, pad-mounted transformers, pole-mounted transformers, pole-mounted riser poles, and substations all have this device installed by an electrician.
DC SPD applications in commercial, industrial, and residential settings
- Communication circuits,
- Power distributions,
- Control cabinets,
- Programmable logic controllers,
- Electronic motor controllers,
- Critical roads,
- Kitchen or household appliances,
- Security systems,
- Medical equipment,
- Lighting circuits,
- Equipment monitoring,
- Back-up power,
- HVAC equipment,
- Entertainment center or stereo equipment,
- Alarm signaling circuits,
- Cable TV feeds,
- Telephone or facsimile lines.
DC SPD for houses
Metal oxide varistors (MOVs) are commonly used in surge protectors to protect you from power surges. As a result, if a power surge happens, the surge protector will protect your household equipment from any harmful electrical currents. Surge protectors are typically installed on the electrical service box in a home.
Air conditioners, pool pumps, generators, solar, cable, network, and communication connections are all potential sources of power surges in your home. As a result, both the interior and exterior of these gadgets must be protected. We recommend installing protection devices on appliances (which we can assist with) and on the main electrical panel.