Planning electrical installation25Protecting the relay output contact and attenuating disturbances in caseof inductive loadsInductive loads (relays, contactors, motors) cause voltage transients when switchedoff.Equip inductive loads with noise attenuating circuits [varistors, RC filters (AC) ordiodes (DC)] in order to minimize the EMC emission at switch-off. If not suppressed,the disturbances may connect capacitively or inductively to other conductors in thecontrol cable and form a risk of malfunction in other parts of the system.Install the protective component as close to the inductive load as possible. Do notinstall protective components at the I/O terminal block.Residual current device (RCD) compatibilityACS150-01x drives are suitable to be used with residual current devices of Type A,ACS150-03x drives with residual current devices of Type B. For ACS150-03x drives,other measures for protection in case of direct or indirect contact, such as separationfrom the environment by double or reinforced insulation or isolation from the supplysystem by a transformer, can also be applied.Selecting the control cablesThe analog control cable (if analog input AI is used) and the cable used for thefrequency input must be shielded.Use a double-shielded twisted pair cable (Figure a, e.g. JAMAK by NK Cables) forthe analog signal.24 VDC230 VAC230 VACDiodeVaristorRC filterDriverelayoutputDriverelayoutputDriverelayoutput
