Motor isolation on a machine Conveyors, pumps, and production equipment | Three-phase motor power circuit; switching frequency and motor starting duty depend on the application. | Select for the motor load category, rated operational current and voltage, short-circuit coordination, and required electrical life. Do not size from motor power alone. | Use the risk-assessed safety control architecture. Where feedback is required, use suitable mechanically linked or mirror contacts and verify their compatibility with the monitoring circuit. | IEC 60947-4-1; IEC 60204-1; ISO 13849-1 or IEC 62061, as applicable. | Inspect terminals, enclosure condition, and switching behavior at intervals set by the manufacturer and site risk assessment. Replace devices that fail inspection or exceed specified electrical or mechanical life. |
Emergency-stop power removal Machine cells and operator workstations | Removal of hazardous electrical power following an emergency-stop command; stopping behavior depends on the machine and risk assessment. | Choose a contactor arrangement suitable for the required safety function, load, and fault conditions. A contactor alone does not establish a safety performance level. | The safety relay or safety controller should monitor the required feedback and prevent restart when a detected fault has not been resolved. Provide a deliberate reset where required by the design. | ISO 13850; IEC 60204-1; ISO 13849-1 or IEC 62061; IEC 60947-4-1. | Test the complete emergency-stop function, including feedback and reset behavior, according to the documented validation and inspection plan. Do not rely on the pushbutton test alone. |
Guard-door interlocking Packaging, assembly, and robotic equipment | Control of hazardous motion or power when an access guard is opened; required stopping time and access protection vary by machine. | Coordinate the contactor with the guard-interlocking device and safety logic. Confirm that the resulting system architecture and component data support the risk-assessed safety requirements. | Consider monitored contactor feedback, guard locking where needed to prevent access before hazards stop, and protection against unexpected restart. | ISO 14119; ISO 14120; IEC 60204-1; ISO 13849-1 or IEC 62061. | Inspect guard alignment, interlock operation, wiring, and contactor feedback. Validate stopping time and protective measures after relevant machine changes or maintenance. |
Heaters and other resistive loads Industrial ovens and process equipment | Resistive load switching; switching frequency, ambient temperature, and enclosure conditions affect component selection and service life. | Check the applicable utilization category, rated current, thermal conditions, and short-circuit protection. Confirm suitability for the actual load rather than assuming motor-load ratings apply. | If the contactor contributes to a safety function, include it in the system-level safety design and monitoring. Use a separate temperature-limiting protective function where required by the process risk assessment. | IEC 60947-4-1; IEC 60204-1; applicable machine or process safety requirements. | Check for loose connections, overheating, contamination, and signs of contact wear. Set inspection frequency based on switching rate, operating environment, and manufacturer guidance. |
Elevators, hoists, and lifting machinery Equipment with suspended or moving loads | Motor or drive-related power control in a high-consequence application; stopping and load-holding functions require application-specific engineering. | Assess the complete drive, braking, and power-isolation system. A contactor is not a substitute for a mechanical brake or other required load-retention measure. | Use safety-rated control and feedback arrangements appropriate to the risk assessment. Verify that faults, loss of control power, and restart conditions are handled as designed. | IEC 60204-1 and applicable lifting-equipment standards and local regulations; ISO 13849-1 or IEC 62061 where relevant. | Follow the equipment inspection and maintenance program. Check contactor operation alongside brake, drive, interlock, and safety-function tests; use qualified personnel for work on lifting systems. |
Selection and lifecycle review Applicable across industrial installations | Normal switching, fault interruption coordination, and safety-related power control must be considered separately. | Compare load rating, coil/control voltage, operating environment, terminal and mounting requirements, electrical endurance, and availability of suitable feedback contacts. Verify all values against current technical documentation. | Determine required Performance Level (PLr) or Safety Integrity Level (SIL) through the applicable risk assessment and design process. Validate the completed safety function; do not infer PL or SIL from a contactor rating alone. | Use the applicable editions of IEC 60947-4-1, IEC 60204-1, ISO 13849-1, and/or IEC 62061, together with local rules and the equipment manufacturer’s instructions. | Keep inspection, test, and replacement records. Determine maintenance intervals from manufacturer instructions, operating cycles, environment, and documented risk; isolate and verify the absence of hazardous energy before service. |