Reliability/Safety Dirt Use suitable casings to avoid possible negative influences due to humidity, corrosive gas, liquid or conducting dust. Impact and vibration Consider possible influences caused by motors, compres- sors, transfer lines, presses, ramming machines and ve- hicles. Electromagnetic interference Consider electromagnetic interference from various sources near the location of installation: motors, switching devices, switching thyristors, radio-controlled devices, welding equipment, arcing, switched-mode power supplies, conver- ters / inverters.
2.5.8 Particular sources of interference Inductive actuators Switching off inductances (such as from relays, contactors, solenoids or switching magnets) produces overvoltages. It is necessary to reduce these extra voltages to a minimum. Reducing elements may be diodes, Z-diodes, varistors or RC elements. To find the best adapted elements, we re- commend that you contact the manufacturer or supplier of the corresponding actuators for the relevant information. 20