Planning the electrical installation55Before opening a contactor (DTC control mode selected)Stop the drive and wait for the motor to stop before opening a contactor between theoutput of the drive and the motor when the DTC control mode is selected. See theappropriate ACS800 Control Program Firmware Manual for the required parametersettings. Otherwise, the contactor will be damaged. In scalar control, the contactorcan be opened with the drive running.Protecting the relay output contacts and attenuating disturbances in caseof inductive loadsInductive loads (relays, contactors, motors) cause voltage transients when switchedoff.The relay contacts on the RMIO board are protected with varistors (250 V) againstovervoltage peaks. In spite of this, it is highly recommended to equip inductive loadswith noise attenuating circuits [varistors, RC filters (AC) or diodes (DC)] in order tominimize the EMC emission at switch-off. If not suppressed, the disturbances mayconnect capacitively or inductively to other conductors in the control cable and forma 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 RMIO board terminal block.24 VD C230 V ACX251 RO12 RO13 RO1X261 RO22 RO23 RO2X271 RO32 RO33 RO3Relay outputs RMIO230 V ACDiodeVaristorRC filterPhone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
