Type 1 AC Surge Protective Devices (Class l SPDs)
Type 1 / Class l
1.10/350 μs direct lightning long waveform, simulating the large energy lightning current of a real direct lightning strike.
2.The core assessment parameter is the impulse current Iimp, which has an extremely high single-release energy and serves as the first critical checkpoint in the entire lightning protection system.
3.Installed at the power input terminals of the main distribution cabinet of the building, the transformer's low-voltage side, etc., as the first level of protection for the entire building.
Type 1 / Class l
The T1 SPD is the "first line of defense" for lightning protection in the power system. Its core advantage lies in its ability to withstand the tremendous energy of direct lightning strikes, protecting key equipment such as the main distribution cabinet.
Wind Power SPD->Type 1 / Class l
Uc(V):
AC760V/1500V
Un(V):
AC690V/1140V
In (8/20 μs):
15kA
Imax(8/20 μs):
30kA
Mode of Protection:
L/N-PEReference Standards:
IEC 61643-11OEM/ODM Acceptable
Additional Function:
Thermal Tripping Protection, Status Indicator, and Remote Signaling
Wind Power SPD->Type 1 / Class l
Uc(V):
AC760V/1500V
Un(V):
AC690V/1140V
In (8/20 μs):
25kA
Imax(8/20 μs):
50kA
Mode of Protection:
L/N-PEReference Standards:
IEC 61643-11OEM/ODM Acceptable
Additional Function:
Thermal Tripping Protection, Status Indicator, and Remote Signaling
AC Power SPD->Type 1 / Class l
Uc:
AC385V/420V/440V
Iimp (10/350 μs):
15kA
In (8/20 μs):
50kA
Imax(8/20 μs):
100kA
Mode of Protection:
L-N/N-PE;L-N,N-PEReference Standards:
IEC 61643-11OEM/ODM Acceptable
Additional Function:
Thermal Tripping Protection, Status Indicator, and Remote Signaling
AC Power SPD->Type 1 / Class l
Uc:
AC385V/420V/440V
Iimp (10/350 μs):
25kA
In (8/20 μs):
60kA
Imax(8/20 μs):
100kA
Mode of Protection:
L/N-PE; L-N, N-PEReference Standards:
IEC 61643-11OEM/ODM Acceptable
Additional Function:
Thermal Tripping Protection, Status Indicator, and Remote SignalingWhat is Surge Protective Device?
SPD Working Principle
A surge protective device, also known as a surge protector or SPD, is designed to safeguard electrical components against surges in voltage that might happen in the electrical circuit.
Whenever a sudden increase in current or voltage is produced in the electrical circuit or communication circuit as a consequence of outside interference, the surge protection device may conduct and shunt in a very short period of time, preventing the surge from damaging other devices in the circuit.
Surge protective devices (SPDs) are a cost-effective method for preventing outages and enhancing system reliability.
They are typically installed in the distribution panels and play an important role in ensuring the smooth and uninterrupted operation of electronic devices in a wide range of applications by limiting transient overvoltage.
How Does Surge Protective Device Work?
SPD Working Principle
The basic principle behind SPDs is that they provide a low impedance path to ground for excess voltage. When voltage spikes or surges occur, SPDs work by diverting the excess voltage and current to the ground.
In this way, the magnitude of the incoming voltage is lowered to a safe level that doesn't damage the attached device.
To work, a surge protection device must contain at least one non-linear component (MOV or GDT), which under different conditions transitions between a high and low impedance state.
Their function is to divert the discharge or impulse current and to limit the overvoltage at the downstream equipment.
Surge protection devices function under the three situations listed below.
A. Normal Condition (absence of surge)
In case of no surge conditions, the SPD has no impact on the system and acts as an open circuit, it remains in a high impedance state.
B. During voltage surges
In case of voltage spikes and surges, SPD moves to the conduction state and its impedance decreased. In this way, it will protect the system by diverting the impulse current to the ground.
C.Back to normal operation
After the overvoltage has been discharged, SPD shifted back to its normal high impedance state.
SOLUTIONS
Experimental Facilities
Cresin is equipped with professional-level surge protection device (SPD) comprehensive performance testing equipment, which can fully adapt to the performance testing and trial research of all categories of T1 and T2 level power surge protection devices.
Large constant temperature and humidity equipment
High current generator equipment
RF network analyzer
Type 1 SPD Installation & Engineering Guidelines
Type 1 SPDs (Surge Protector) must be installed according to electrical standards. They are connected in parallel ahead of the main distribution panel or circuit breaker, with wiring following standard diagrams and remote signaling terminals. This ensures front-line protection at the LPZ 0/1 boundary.
Wiring Principles & Connection Integrity
Type 1 SPDs (Surge Protectors) are typically connected in parallel ahead of the main circuit breaker in the main distribution panel.
L, N, and PE are connected to the line, neutral, and protective earth.
Used with dedicated circuit breakers or fuses, they respond quickly to system surges.
Wiring should be kept short and secure (≤ 0.5 m) to minimize inductance and contact resistance, reducing induced voltages on the SPD.
Remote Signaling Terminals
Type 1 SPDs (Surge Protectors) with remote signaling terminals provide operational status feedback.
Dry contacts output SPD status and fault signals to the control panel.
Connect the signal wires to the corresponding monitoring terminals on the control panel to enable remote monitoring.
Alert signals are generated in case of faults or abnormal conditions, assisting maintenance personnel in quickly identifying issues and improving system maintenance efficiency.
FAQ
Where is Type 1 SPD commonly used?
Type 1 SPDs are commonly used in main distribution boards, industrial plants, solar PV systems, wind power systems, telecom stations, commercial buildings, and facilities with external lightning protection systems.
Can Type 1 SPD replace Type 2 SPD?
Not always. Type 1 SPD is mainly used for high-energy lightning current discharge, while Type 2 SPD provides further voltage limitation in downstream distribution panels. In many systems, Type 1 and Type 2 SPDs are used together for coordinated protection.
What is the key parameter of a Type 1 SPD?
The key parameter of a Type 1 SPD is Iimp, which represents the impulse current discharge capability under a 10/350 μs waveform. This value indicates how much lightning current the SPD can safely discharge.
When should I use a Type 1 SPD?
You should use a Type 1 SPD when the building has an external lightning protection system, overhead power lines, high lightning exposure, or when the installation is located in an industrial, photovoltaic, wind power, or critical infrastructure environment.
What is a Type 1 / Class I SPD?
A Type 1 / Class I SPD is designed to discharge high-energy lightning current and is usually installed at the main power entrance of a building or electrical system. It is suitable for locations with direct lightning strike risk or external lightning protection systems.
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