Surge arrester varistor type T3 4P TN-S network In=3kA Up1, 4kV contact SPC403N

Protection of electrical installations and devices

The SPC403N varistor surge protector is a key element ensuring the safety of electrical installations in residential and commercial buildings. Designed for mounting on a TH-35 mm DIN rail, it effectively protects against the effects of atmospheric surges and disturbances in the power supply network. This is a Class T3 device, which means it is used as the last line of defense against surges, directly before the protected device.

Construction and operation

The four-pole surge protector (4P) is designed for TN-S networks. Its operation is based on the use of varistors – electronic components characterized by a fast response to surges. When a voltage exceeding the permissible value is detected, the varistor reduces it to a safe level, protecting the connected devices. Optical indication of operation facilitates the identification of a situation in which the surge protector has reacted to a surge – this information is useful for diagnosing network problems.

Parameters and application

The device is characterized by a rated current of 26A and is adapted to operate in 230V AC and DC networks. It provides a protection level of 1.4 kV (L-PE/N-PE) and 1.25 kV (L-N), which guarantees effective protection against damage caused by surges. The maximum conductor cross-section that can be connected to the surge protector is 4 mm² for solid and stranded conductors and 2.5 mm² for flexible conductors. It is important to select appropriate overcurrent protection – it is recommended to use a fuse with a value of no more than 16A (parallel connection) or 25A (series connection). The total discharge current of the surge protector is 9kA, which demonstrates its high effectiveness in absorbing surge energy.