What is Time delay relay?    

When power comes or you switch on your stabilizer, the stabilizer energizes immediately but gives it's output to power appliance / Airconditioner after some delay i.e. after 1 or 2 minutes.

This process is done by an electromagnetic switch (Relay). So it is called the Time delay Relay.

How will I select stabilizer rating for my home/office?    
     
Before selection the stabilizer you need to know how much power you use. By taking an inventory of all the essential electrical loads in your house / office, and doing a basic electrical load evaluation, you can get a good idea how much power your system needs to produce.

Second, you have to know about the power Fluctuations situations also that means what voltage minimum / maximum you are getting from the main A.C supply. In brief, you have to select the Input Voltage window and the power consumption of your appliance. Gechy Electronic will help you choose the suitable selection of Automatic voltage stabilizer.