Types Of Citel's Surge Arresters
Types of surge arrester-cataloge
CITEL AC power surge protectors offer three levels of surge protection corresponding to different IEC or EN classes.
Type 1 Surge Protectors
Type 1 surge protectors are designed to be installed where a direct lightning strike risk is high, especially when the building is equipped with external lightning protection system (LPS or lightning rod). In this situation EN 61643-11 and IEC 61643-11 standards require the Class I test to be applied to surge protectors : this test is characterized by the injection of 10/350 μs impulse current in order to simulate the direct lightning strike consequence. Therefore these Type 1 surge protectors must be especially powerful to conduct this high energy impulse current.
Type 2 surge protectors
Type 2 surge protectors are designed to be installed at the beginning of the installation, in the main switchboard, or close to sensitive terminals, on installations without LPS (lightning rods). These protectors are tested following the Class II test from IEC61643-11 or EN61643-11standards based on 8/20 μs impulse current injection.
Type 3 surge protectors
In case of very sensitive or remote equipment, secondary stage of surge protectors is required : these low energy SPDs could be Type 2 or Type 3. Type 3 SPDs are tested with a combination waveform (1,2/50 μs - 8/20 μs) following Class III test.
Choosing the right AC Power Surge Arrester
CITEL's line of AC power surge protectors is designed to cover all possible configurations in low voltage installations. They are available in many versions, which differ in :
Type or test class (1 , 2 or 3)
Operating voltage (Uc)
AC network configuration (Single/3-Phase)
Discharge currents (Iimp, Imax, In)
Protection level (Up)
Protection technology (varistors, gas tube-varistor, filter)
Features (redundancy, differential mode, plug-in, remote signaling...).
The surge protection selection must be done following the local electrical code requirements (i.e. : minimum rating for In) and specific conditions (i.e. : high lightning density).
Choosing the Type of surge protectors
This choice is in relation to the LPS condition (Lightning Protection System) and the SPD location in the installation.
Choosing of the operating voltage Uc
The SPD Uc voltage (maximum continuous operating voltage) depends on:
Nominal voltage of the AC network (Uo)
Level of possible temporary overvoltages (TOV) Uτ
Type of AC system (TN, TT, IT).
Operating voltage Uc (Line/Ground)
AC network configuration
DS surge protectors are available for single, 3-Phase and 3-Phase + neutral AC networks.
Choosing Iimp
The impulse current Iimp is defined for Type 1 SPD. The minimum rating for Iimp is 12.5 kA by pole, following IEC 60364-5-534 . This level is adapted to the real phenomenon. CITEL proposes, in its Type 1 SPD range, 2 levels of Iimp current : 15 and 25 kA.
Choosing In and Imax currents
The relevant nominal discharge current In for the SPD is in relation with the lightning risk in the installation area. The minimum rating of In for a SPD connected at the installation entrance is 5 kA (8/20 μs waveform), required by standard. Nevertheless higher ratings are advised in case of high lightning density. Moreover higher values of In current will increase the SPD lifetime. Imax (max. discharge current) rating is linked to In .
Choosing the protection level Up
The user must select a surge protector with a protection level Up adapted to the withstand level of terminal equipment. In every case, the lower the protection level Up, the better the protection. IEC 60364 standard calls for the minimum protection level of 2.5 kV for a SPD connected at the entrance of a 230/400 V network : this level is in compliance with the withstand of robust devices (electromechanical type). Electronic-based terminals have lower impulse withstand and require a better protection : so, surge protectors with 1.5 kV protection are necessary to provide efficient protection.
A relevant choice of the SPD technology, as well as the use of coordination diagram can help to improve the protection level.
Telephone And Data Network Surge Arrester
Telecommunications and data transmission devices (PABX, modems, data terminals etc..) are becoming increasingly vulnerable to lightning-induced voltage surges. These devices are becoming more complex and are currently connected to several networks : this situation increases the risk for these sensitive devices to be stressed by destructive surge voltages, induced by lightning or by electrical switching operations. Surge protectors for telecom and data transmission terminals divided in 3 types :
Surge protectors for telecom networks
Surge protectors for industrial networks
Surge protectors for LANs
These ranges are different by their electrical diagrams and their mechanical configurations, adapted to the need of each type of network.
Protection of the radiocommunication equipment
Radiocommunication systems, connected to antennae, are especially exposed to lightning phenomena, the maximum risk being a direct strike on the antenna pole. Equipment, as GSM/UMTS or TETRA base stations, must consider this risk in order to insure a relevant service continuity. CITEL offers several surge protection technologies for RF lines to comply to the different operation requirements.
For more information, please contact us.
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