A jam cleared on a palletiser, and a tech needs to pull the perimeter guard panel covering contactor KM3 to inspect the wiring behind it. The line was stopped at the main disconnect, but the safety procedure calls for a verified zero-energy check before any guard comes off. You place your meter across the line side of KM3, L1 to L2, expecting the verification reading. The system is a 400 V three-phase supply. After isolation, you read the actual voltage across the same two terminals and want to confirm it is at or near zero before the panel is touched. The meter shows 2 V across L1 and L2 of KM3. What residual voltage, as a percentage of the nominal line voltage, does this represent?