Annex 10 (contd..)

Preventive Maintenance Schedule for Protection Systems

S. No.	Tasks assigned	Shut Down (SD) Or Without Shut Down (WSD)	Periodicity
	PLCC SYSTEM
	Power supply measurements	SD	Yearly
	Transmitter checks	SD	Yearly
	Receiver checks	SD	Yearly
	Checks for Alarms	SD	Yearly
	Reflex test	SD	Yearly
	BUS BAR PROTECTION
	Primary injection test	SD	As per requirement
	Protection stability and sensitivity checks (To be done whenever the protection AC circuits are disturbed like addition of new feeder	SD	As per requirement

*Includes Z1, Z2, Z3 and Z3 (reverse)

**Includes Z1, Z2, Z3 and Z3 (reverse)

Note: The tests listed under (A) and (B) above may be carried out with out a Line SD ensuring

i) Proper isolation of the relay under test

ii) The Other Main Protection of the Line is healthy and is in service