Surge Protection

Type 2 AC surge protection device TRS4 series

  • Varistor surge arrester
  • Installtion to sub-distribution boards
  • For protection of installations and equipments againt impact of induced overvolatge during a lightning strike or switching overvolatges
  • Optional remote fault signalling(S)

The working principle of surge protection device:

The surge arresters commonly defined as SPDs (Surge Protection Devices), are devices designed to protect electric systems and equipment against transient and impulse overvoltages such as those caused by lightning strikes and by electric switching.

Their function is to divert the discharge or impulse current generated by an overvoltage to earth/ground, thereby protecting the equipment downstream.

SPDs are installed in parallel with the electric line to be protected. At the mains rated voltage, they are comparable to an open circuit and have a high impedance at their ends.

In the presence of an overvoltage, this impedance falls to very low values, closing the circuit to earth/ground.

Once the overvoltage has ended, their impedance rises again rapidly to the initial value (very high), returning to open loop conditions.

The Type 2 SPD is the main protection system for all low voltage electrical installations. Installed in each electrical switchboard, it prevents the spread of overvoltages in the electrical installations and protects the loads.

Type 2 surge protective devices (SPDs) are designed to protect electric installations and sensitive equipment against indirect surges and ensuring a low protection level (Up).

Type 2 surge protective devices provide effective protection against these dynamic disturbance variables. Whether in an industrial environment or in a residential building, type 2 protection ensures basic protection for your installations and devices.

The TRS4 series type 2 SPDs are available have a discharge capacity of 10kA, 20KA, 40KA, 60KA in single-phase or 3-phase configuration and with various voltages in order to protect any type of power supply system.

THOR Type 2 DIN-rail SPD features are offering quick thermal response and perfect cut-off function and providing fast and reliable protection for various power supply systems.And its capacity to safely discharge current with 8/20 μs waveform.Built with window fault indication and optional remote alarm contact, it can monitor the operating status of the SPD itself.

Device Category

Parameter/Type TRS4-D10 TRS4-D20 TRS4-C40 TRS4-B60
Nominal volatge                                                 Un  230 V AC
Maximum operating voltage                                Uc  275 V AC
Nominal discharge current (8/20μs)                      In 5 kA 10 kA 20 kA 30 kA
Maximum discharge current (8/20μs)                Imax 10 kA 20 kA 40 kA 60 kA
Voltage protection level                                      Up ≤ 0,7 kV ≤ 1,0 kV ≤ 1,3 kV ≤ 1,5 kV
Response time                                                     ta  < 25ns
Cross-section of connected conductors solid (min/max) 16 mm2 / 35 mm2
Cross-section of connected conductors stranded (min/max) 16 mm2 / 35 mm2
Fault indication red indication field
Remote indication potential-free change-over contact
Remote indication contacts 250 V / 0,5 A AC, 250 V / 0,1 A DC
Cross-section of remote indication conductors 1,5 mm2 
Degree of protection IP20
Range of operating temperatures (min/max) -40℃~+70℃
Humidity range 5%~95%
Mounting DIN rail 35 mm
According to standard EN 61643-11:2012, IEC 61643-11:2011 / T2
Remarks Other Uc can be customized.(420V AC, 385V AC, 320V AC, etc.)