Differentiate between two-wire and three-wire control

Differentiate between two-wire and three-wire control
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1 Answer

Answer :


Two-Wire Control 
Three-Wire Control
1 The control component offers only two-wires for its connection in control circuit.
The control components offer threewires for their connection in control circuit.
2 The control device is usually a switch, may be automatic such as limit switch, float switch etc.
The control components are usually push-buttons (Start and Stop).
3 On supply failure, the motor stops, but when it restores, the motor restarts automatically without starter and may get damaged. Thus motor is not protected from No-volt condition. 
On supply failure, the motor stops and when it restores, the motor can not start automatically. The operator need to start the motor using starter. The safe starting ensures the Novolt protection. 
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