auxiliary contacts การใช้

• Auxiliary contacts of contactors are used in control circuits and are rated with NEMA contact ratings for the pilot circuit duty required.
• Sometimes an economizer circuit is also installed to reduce the power required to keep a contactor closed; an auxiliary contact reduces coil current after the contactor closes.
• For instance, what happens if the Control System / PLC loses the motor's auxiliary contact as the door is rising ?, Does the Control System / PLC turn off the output which raises the door?
• Force-guided contact relays are made with different main contact sets, either NO, NC or changeover, and one or more auxiliary contact sets, often of reduced current or voltage rating, used for the monitoring system.