The cause of electrical fast transients (EFT) come from an arc when mechanical contact is open due to a switching process. Given the fast rise time and voltage of these pulses having a solid ground connection is important during the testing process. Testing for EFT often requires a capacitive coupling clamp (CCL), which is employed to add disturbances to nominal signals.

Most of our customers will simply place the EFT generator on a bench, ground it to the chassis, and be off and rolling. There are diagrams avaialble that specify spacing, insulation, placement of the generator, etc... We have found that in most cases, these aren't detrimental pieces to passing IEC 61000-4-4.

• EFT/Burst Generator
• GP: Ground Plane
• Coupling Clamp (Data Lines)
• 3 Phase Coupler (Higher Power EUT)
• Insulation Material (Polyvinyl Chloride preferred material)
• Non-metallic test table
• Calibration Kit (Optional)

Commercial Electronics - IEC 61000-4-4
Medical Electronics - IEC 60601-1-2
Automotive Electronics - ISO 7637, ISO 16750-2
Military Electronics - MIL-STD-461, MIL-STD 1275
Aerospace & Avionics Electronics - DO-160 Section 17

EUTs, whether stationary floor-mounted or table top, and equipment designed to be mounted in other configurations, shall be placed on a ground reference plane and shall be insulated from it by an insulating support 0.1 m ± 0.01 m thick.

In the case of table-top equipment, the EUT should be located 0.1 m ± 0.01 m above the ground reference plane. Equipment normally mounted on ceilings or walls shall be tested as table-top equipment with the EUT located 0.1m ± 0.01 m above the ground reference plane.

The test generator and the coupling/decoupling network shall be placed directly on, and bonded to, the ground reference plane. The ground reference plane shall be a metallic sheet (copper or aluminium) of 0.25 mm minimum thickness; other metallic materials may be used but they shall have 0.65 mm minimum thickness.

The minimum area of the ground reference plane is 1 m × 1 m. The actual size depends on the dimensions of the EUT. The ground reference plane shall project beyond the EUT by at least 0.1 m on all sides.

The minimum distance between the EUT and all other conductive structures (e.g. the walls of a shielded room), except the ground reference plane shall be more than 0.5 m.

All cables to the EUT shall be placed on the insulation support 0.1 m above the ground reference plane. Cables not subject to electrical fast transients shall be routed as far as possible from the cable under test to minimize the coupling between the cables.

• Troubleshooting EFT/Burst Failures with a Near Field Probe
• Waveform Verification for IEC 61000-4-4 Electrical Fast Transients
• IEC 61000-4-4 Overview
• EMC Precompliance Testing