Siemens 7SA511 manual Terms

7SA511 Line Protection RelayChapter 1

Terms
annunciation	1. Activating the various relay outputs (LCD, LEDs, output relays)
	when events occurs.
	2. Messages that appear on the operator panel LCD in the event log or
	target logs are also called annunciations.
binary input	A relay input terminal that responds to the presence or absence of voltage
	on the terminal in a digital (on/off) manner.
block	1. Prevent normal operation or function.
	2. Group of memory addresses.
compensated	The neutral system point is inductively grounded to compensate for the
(system)	distributed phase-to-ground system capacitance.
dead time	Time allowed following fault clearance before attempting an automatic
	reclose.
drop-off	Drop-out (used in the LCD text).
drop-out	Return to a normal or no-fault state.
earth	Electrical ground.
fault loop	In phase-selective fault detection systems, this term describes the current
	path for phase-to-phase or phase-to-ground faults. For example, if a short
	circuit occurs between phase 1 (L1) and phase 2 (L2), the fault loop is
	L1-L2. The currents and voltages of the fault loop are decisive when
	calculating the distance to fault.
forward	Direction—normally downstream towards the line or load (i.e., toward the
	protected component).
high-set	An overcurrent protection element that operates independently of the
	definite time or inverse time elements and typically has a high pickup value
	and a small or zero (instantaneous) time delay.
isolated (system)	The neutral system point is purposely not connected to ground
	(ungrounded).
marshalling	Configuring the I/O units (LEDs, trip relays, etc.)

July 27, 1995 1-5