The LI-550C Line Impedance Stabilisation Network (LISN) provides the necessary measurement platform for performing power line conducted emissions compliance testing as required by most worldwide standards for commercial products.

The LI-550C is compliant with both CISPR 25 and CISPR 16-1-2 . The LISN provides defined stable impedance and isolates the EUT from power source influences, thereby providing accurate and repeatable results. The LI-550C includes one pair of, separately housed, single-conductor networks, to be installed in series with each current-carrying conductor in a single- phase, dual-phase or DC power system. A second LI-550C pair can be used to accommodate 3-phase power systems (Wye or Delta configurations). The LI-550C is equipped with Superior Electric SUPERCON® shrouded sockets at the mains (power input) and EUT (power output) ports. The matching colour-coded plugs for connection to the mains and EUT wiring are included.

This LISN uses air-core inductors to prevent saturation and permeability variation. The mounting plate of the LI-550C is left unpainted in order to facilitate connection to earth ground in its installation, which is essential due to high leakage current.