Siemens SG8158-00 manual Trip Contacts, Comm Events, Breaker Monitoring

Control & Communications

6

6.4 Trip Contacts

The ISGS relay offers up to three trip contacts which are monitored by the microprocessor. Trip contacts may be con- figured by the user to trip the relay based on any of a number of functions. Trip contact reaction time is about 4.5 ms.

The relay displays the options at each matrix position in the sequence listed in the table below.

6400	Trip Contacts
Address	Para-	Matrix	Option	Option (cont.)
	meter	Position
6401	Contact 1	001	not matrixed	59 Trip
		to	BI1	47 Trip
		020	BI2	OvrBrOps PU
			BI3	OBrAmps PU
			BI4	OvrAmps-
		(Options	OC Trip	Dmd PU
		apply to	NonOC Trip	OkWDmd PU
		each	Relay Tripped	OvrkVAR PU
		matrix	50HS Trip	OvrkVA PU
		position)	50HSN Trip	PFLag PU
			81O Trip	PFLead PU
			81U Trip	50BF Trip
			47N Trip	TrScMon PU
			50 Trip	TrCoilCont PU
			50N Trip	BrMech PU
			51 Trip	CommEvent 1
			51N Trip	CommEvent 2
			67 Trip	CommEvent 3
			67N Trip	CommEvent 4
			27 Trip	CommEvent 5
6402	Contact 2	001-020	(same as Contact 1 above)
6403	Contact 3	001-020	(same as Contact 1 above)

6.5 Comm Events

Protective functions are internally generated events that can trip a relay. For the protection to function properly, the pro- cessor interprets these events (inputs) and makes a decision. Communication (Comm) events are externally generated messages that can trip a relay without any interpretation. This remote communication allows Comm events to control outputs (contacts), such as opening a breaker; or switch parameter sets if matrixed to a binary input. Comm events are sent from a PC or other devices on the RS-232 or RS-485 networks.

Comm events can be blocked (disabled) with binary inputs to prevent remote parameterization during service periods or as a general safety measure. Refer to the list of binary inputs in Section 6.2.

6.6 Breaker Monitoring

To increase the security of the protective system, it is helpful to monitor several parameters directly from the switchgear. The ISGS relay can monitor the components such as the 52a and the 52b switches, the traditional circuit breaker position lamps, and the tripping voltage supply.

The 52a and 52b switches have a total of four possible posi- tion combinations which can be decoded as illustrated in Table 6.1. The 52a and 52b switches referred to are those which traditionally provide indication of circuit breaker posi- tion (52b) and trip coil continuity (52a). All error reporting can be enabled and disabled, and the actions to be taken are configurable.

Table 6.1 52a and 52b Switches Decoding

52a Switch	52b Switch	Condition Registered
Position	Position
Open	Open	Trip Coil Continuity Error, or
		Breaker Withdrawn
Open	Closed	Circuit Breaker Open
Closed	Open	Breaker Closed
Closed	Closed	Circuit Breaker Mechanism Error

The ISGS relay monitors:

•breaker position

•trip coil continuity

•trip source impedance.

Breaker position is sensed through dedicated binary inputs that monitor the 52a and 52b switches on the breaker mech- anism (breaker mounted). Trip coil continuity is monitored by continually sensing a current that flows through the trip coil. Trip source impedance is checked using a switchable elec- tronic load across the trip voltage supply.

8300	Breaker Monitoring
Address	Function/	Options
	Parameter
8301	TripSrcImp	Enabled or Disabled
8302	TripSrcFail	Yes or No
8303	TrpCoil Cont	Enabled or Disabled
8304	TrpCoilFail	Yes or No
8305	BrkrMech	Enabled or Disabled

Exceptions to the normal operating conditions include the presence of push-to-test switches across either the a-switch, b-switch, or both. A push-to-test switch across the b-switch will produce a false indication of a breaker mecha- nism error when the breaker is actually closed. A push-to test switch across the a-switch (and hence across the trip solenoid) will produce a false indication of a breaker mecha- nism error when the breaker is actually closed.

34 Siemens Energy & Automation, Inc.