Understand the concept
A contactor lets a lower-power control circuit switch a higher-power motor circuit. An overload relay is intended to protect a motor against prolonged excessive current, not replace branch-circuit short-circuit protection.
Transformers transfer energy between windings magnetically. Their voltage ratio approximately follows the turns ratio, subject to design and losses.
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Practice task
Draw a ladder diagram with stop/start buttons, a holding contact, a coil, and an overload contact. Keep any practical work limited to a safe trainer and qualified supervision.
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