What are the common-mode and differential-mode test voltages for the surge function of an edge computing box?

Edge computing boxes undergo surge immunity testing according to IEC 61000-4-5, with a severity level typically selected as Level 3. For industrial environments, the power port uses a common-mode ±2kV and a differential-mode ±1kV. For signal ports, the common-mode ±1kV and differential-mode ±0.5kV are used. A typical test combination for the power port is: differential mode applied between L and N with a 2Ω source impedance; common-mode applied between L-PE and N-PE with a 12Ω source impedance; and the signal port uses a 42Ω source impedance. For the 24V DC power port protection of the edge computing box, a TVS 5.0SMDJ33CA is commonly used in conjunction with a varistor 14D391K. The former (5.0SMDJ 5000W 33V, Rule B, actual VRWM = 28.2V, clamping 53.3V) and the latter (14D391K, varistor voltage 390V, capable of absorbing high energy) is recommended. For communication ports such as Gigabit Ethernet, a common-mode inductor CMZ2012A-900T is recommended. Its naming is CM common-mode, Z impedance 2012, and its size is 2.0 × 1.2mm. The 900T impedance is 90Ω, and the 100MHz frequency is compatible with ESDLC3V3D3B TVS, which is named ESD electrostatic LC low capacitance 3V3 with a turn-off voltage of 3.3V. The D3B SOD323 package is bidirectional and can withstand 1kV surges, ensuring long-term reliability of the edge box.