Surge, Telecom, ring wave CDNs for interconnection and control lines
Conducted immunity test specified in the IEC 61000-4-X series are applied to a broad series of ports/lines. The major categories in standards like IEC 61000-4-5 and IEC 61000-4-12 are: AC/DC power lines and interconnection lines.
How to choose a CDN for interconnection lines?
The major differences when applying surge, telecom surge (10/700 μs voltage waveform as per Annex A from IEC 61000-4-5) and ring wave refer to test levels, source impedance and coupling mode (differential and/or common mode).
The interconnection lines are themselves subdivided categories in function of two parameters: symmetrical/unsymmetrical and shielded/unshielded. Hence four categories of interconnection lines result, as described in the table below.
Surge 1.2/50 μs and ring wave are to be applied in differential mode and common mode on unsymmetrical unshielded lines. There are no requirements to apply 10/700 μs surge on unsymmetrical unshielded lines.
Surge, telecom surge and ring wave disturbances are to be applied only in common mode to symmetrical unshielded lines.
Finally, shielded lines do not require a CDN, as the impulses coming from generator output are applied directly on the shield.
Test equipment
The CDNs provided by EMC PARTNER for interconnection lines (listed in the table above) are designed to cover a broad range of applications. CDN-UTP8 ED3 for example, can be used for both high speed symmetrical (1 Gbps) and unsymmetrical interconnection lines, apply up to 6 kV surge and ring wave disturbances in both differential mode and common mode. Technical specifications can be found in the technical specifications.
IEC 61000-4-4 | Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques |
IEC 61000-4-5 | Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test |
ITU-T K.20 | Resistibility of telecommunication equipment installed in a telecommunication centre to overvoltages and overcurrents |
ITU-T K.21 | Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents |
ITU-T K.44 | Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents - Basic Recommendation |
 | 500V - 30 kV impulse voltage generator | |
 | Combination Wave Generator according to IEC 61000-4-5 12kV/6kA 2 Ohm with automatic three phase coupling network 480V and 32A. | |
 | 12 kV impulse generator with CWG, 1-Phase CDN and 10/700 | |
 | 24 kA impulse current generator with 4 outputs | |
 | Power induction tester | |
 | 8KV EFT/Burst, SURGE, Ringwave and 10/700us impulse generator | |
 | Impulse current generator 10/350 |
 | External Red and Green warning lamps | |
 | Coupling Network for power induction tests according to ITU-T K44 | |
 | Extension Network to perform Power Contact (PC) tests according to ITU-T K.44 | |
 | External emergency stop switch | |
 | Test cabinet made of acrylic glass, With interlock safety switch. | |
 | 3000W Single phase Power Source with pre-programmed voltage & frequency combinations | |
 | Resistor set for the power contact testing in accordance with ITU-T K44 |
 | EFT, Surge & Ring wave automatic 3-phase CDN for power supply lines. EUT max 690Vac / 1500Vdc / 32A per phase | |
 | CDN for 1.2/50, Ringwave and 10/700 surge coupling 6kV to 2 pair (4 wires) balanced communication lines | |
 | 6 kV Impulse testing of up to 4 Unbalanced Twisted Pairs (UTP) |
