Magnetic starter

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A magnetic starter is a relay specially designed to provide power to electric motors. The magnetic starter is a connector with an overload relay attached physically and electrically. The overload relay will open the supply voltage to the starter if it detects an overload on a motor. It does this by putting heaters in series with the contactor supplying the voltage to the motor. When these heaters are heating by the current, their heat indirectly heats an element such as bimetal strip, which trips mechanical latch opens a set of contacts that are wired in series with the supply to the contactor feeding the motor. The characteristics of the heaters can be matched to the motor so that the motor is protected against overload.

Magnetic motor starters are electromagnetically operated switches that provide a safe method for starting large motor loads.

[edit] See also

• Contactor

[edit] Further reading

• Frane, James T. (1994). "Magnetic starter". Craftsman's Illustrated Dictionary of Construction Terms. Craftsman Book Company. ISBN 1572180080. 
• Smeaton, Robert W.; Ubert, William H. (1998). Switchgear and Control Handbook. McGraw-Hill. ISBN 0070584516.