Tripping Logic Of The Entire Device - Siemens SIPROTEC 7SA522 Manual

2 Functions
Spontaneous
Displays

2.20.1.5 Tripping Logic of the Entire Device

Three-pole Tripping
Single-Pole Trip-
ping
338
Spontaneous displays are fault messages which appear in the display automatically
following a general fault detection or trip command of the device. For the 7SA522,
these messages include:
"Relay PICKUP":
´38 7LPHµ:
´75,3 7LPHµ:
´GLVW µ:
In general, the device trips three-pole in the event of a fault. Depending on the version
ordered, (13th position of the ordering code = "4" to "7") single-pole tripping is also
possible (see below). If, in general, single-pole tripping is not possible or desired, the
output function ´5HOD\ 75,3 SKµ is used for the trip command output to the
circuit breaker. In these cases the following sections regarding single-pole tripping are
not of interest.
Single-pole tripping only makes sense on overhead lines, on which automatic reclo-
sure shall be carried out and where the circuit breakers at both ends of the line are
capable of single-pole tripping. In such cases, the faulted phase may be tripped single-
pole and subsequently reclosed; in the case of two-phase and three-phase faults with
or without earth, three-pole tripping is usually carried out.
Device prerequisites for phase segregated tripping are:
• that phase segregated tripping is provided by the device (according to the ordering
code);
• that phase segregated tripping is provided by the protection function which trips (not
provided by e.g. high-current switch-on-to-fault protection, overvoltage protection,
overload protection);
• that the binary input ´!S 7ULS 3HUPµ is configured and activated or the internal
automatic reclosure function is ready for reclosure after single-pole tripping.
In all other cases tripping is always three-pole. The binary input ´!S 7ULS 3HUPµ
is the logic inversion of a three-pole coupling and is activated by an external auto-re-
closure device as long as this is ready for a single-pole auto-reclosure cycle.
With the 7SA522, it is also possible to trip three-pole when only one phase is subjected
to the trip conditions, but more than one phase indicates a fault detection. With dis-
tance protection this is the case when two faults at different locations occur simulta-
neously but only one of them is within the range of the fast tripping zone (Z1 or Z1B).
This is selected with the setting parameter SROH FRXSOLQJ (address ), which
is set to ZLWK 3,&.83 (every multiple-phase fault detection causes three-pole trip)
or ZLWK 75,3 (in the event of multiple-phase trip commands the tripping is three-
pole).
The tripping logic combines the trip signals from all protection functions. The trip com-
mands of those protection functions that allow single-pole tripping are phase segre-
gated. The corresponding messages are named ´5HOD\ 75,3 /µ, ´5HOD\ 75,3
/µ and ´5HOD\ 75,3 /µ.
protective function that picked up;
the operating time from the general pickup to the
dropout of the device, the time is given in ms;
the operating time from general pickup to the first trip
command of the device, in ms;
the distance to fault in kilometres or miles derived by
the distance to fault location function (if possible).
7SA522 Manual
C53000-G1176-C155-3