Class C (Type 2) Low Voltage Surge Arrester

Class C Surge Arresters (Type 2) Usage

Class C surge arresters are used to protect against network surges, switching surges, sudden overvoltage & undervoltage, harmonics, and all other surges occurring on an 8/20 μs curve, except lightning. According to IEC standards, they are used in all secondary distribution panels, factory machine and automation panels, residential main panels, and elevator panels. Using Class C surge arresters will protect from secondary surges, which constitute approximately 65% of all surge types.

Considering the surge curves, products with a minimum protection capacity of 40 kA (Imax) and a voltage protection level Up ≤ 1.25 kV are preferred to handle varying surge conditions. For systems powered by classic mains, the continuous operating voltage is 230/440 V (Uc).

Class C surge arresters do not provide lightning protection; however, stepwise protection must always be used for non-lightning surges. Studies show that electrical faults account for a higher percentage of failures in electrical and automation systems compared to floods, fires, or earthquakes. Therefore, using Class C surge arresters protects systems against sudden overvoltage events in daily life.

You can request applications and product offers for products with the above values from our French and German partners through Yıldırımdan Korunma Merkezi. For Class C products with 40 kA 3P+N and VG technology with warning signal output, you can access special campaign prices throughout September by contacting info@yilkomer.com.

Class C surge arresters are also referred to as Type 2 or Class 2 due to terminology differences in standards. Products with EN 61643-11, IEC 61643-11, and UL1449 certifications are highly recommended. When a surge exceeds the device’s capacity, cartridges may deactivate. In such cases, products with LED indicators are preferred to monitor cartridge status (red/green). Warning contact output C-class surge arresters can be monitored remotely via a computer or signal lamp. VG technology (varistor with carbon and gas discharge tubes) reduces the risk of cartridge deactivation.

It is recommended to install Class C surge arresters in parallel with a minimum 6 mm² cable. Cable lengths should not exceed 50 cm. For potential short circuits, a protective fuse should be installed before the surge arrester. Fuse values are specified in the manufacturer’s datasheets.