Problems about IDMT relay

[Peter Pun]

Today i found that there are two questions about IDMT relay which i dont know how to answer.
1. What will haggen if electrician forget to insert the "plug" in the IDMT protection relay?
2. Discrimination is important in electric circuit protection. Please tell me how to apply the plug settings of the overcurrent to achieve discrimination of the IDMT protection relay R1 and R2 (consider the type of IDMT protection relays, overload and short circuit fault. No calculation is required)
thank you very much!

 

[Marvo]

This isn't really my area of expertise but I've had some experience. With the relays I've seen the multiplier plug has several possible positions and if it's left out entirely the relay would be at its lowest sensitivity. Usually discrimination would involve setting increasing time delays as you progress along the radial feeder.

**Edit** Is this some kinda homework question?