The EBN 2, or the compact flush-mounted version EBN U2, is used wherever very high power-on surge currents could damage relay contacts. Electronic ballast units, fluorescent lamps and similar loads can generate power-on surge currents of far more than 100A! The same applies to compensation capacitors. Connection of the EBN 2 / EBN U2 behind the relay contacts reduces the surge currents to values which will not damage the contacts.