Hi Sunny,
Welcome to our forum. ;D
I found the project: http://www.electronics-lab.com/projects/motor_light/042/index.html
It says that the time delay is important and is missing from other similar circuits:
"Its salient feature is that no relay hunting is employed. This draw back is commonly found in the proctors available in the market."
Without a time delay the voltage would be wrong, so the circuit would disconnect then the circuit would turn on too soon, increasing damage of the protected device from overheating. Therefore the relay will hunt off, then on, then off again, then on again ...... A good way to destroy a refrigerator. With this circuit you can select the amount of delay time to allow the protected device to cool. ;D