Cable lengths for EMC testing
We receive numerous questions when clients submit products for EMC testing and a typical one concerns associated cables. The only requirement indicated in EMC standards is that cables used in testing should reflect a typical installation.
If the power supply is only intended with cables of a specified length, that length should be used.
The EMC test arrangement usually requires cabling draped over the edge of the test table by a length of 40cm, then looped back to the top table with connection to a typical load. This gives a total length of approx 1m. Excess cable lengths should be folded in a horizontal bundle 30 to 40cm at a 40cm height above the ground plane. This provides both a vertical and horizontal component for radiation.
For testing, 1-3m lengths are good. Folding of cables become difficult for lengths greater than 5m. Just ensure as a test house, we’re provided cable lengths that are typically used in an installation.