10
Application
example 2
Synchronism check
between busbar and
line
Fig. 5. Synchro-check relay SPAU 140 C used for checking synchronism between busbar and line
In the application illustrated in Fig. 5 stage 1 of
the synchro-check relay is used for checking the
synchronism between the busbar and the line.
Stage 2 is inactive (SGF/7 = 0 and SGF/8 = 0).
Both the synchro-check function and the volt-
age-check function of stage 1 are operational
(SGF/3 = 1 and SGF/4 = 1).
Command mode operation has been selected
for stage 1 (SGB/3 = 1), which means that press-
ing a push-button activates a request signal for
the synchro-check relay to close the circuit
breaker. This request signal should be active
throughout the specified checking time. The
permission for the relay to operate is given over
this request input, and once the conditions for
CB closing are met, the synchro-check relay de-
livers a close signal to the circuit breaker via out-
put contact C. Should the attempt to close the
circuit breaker fail (SGR/1 =1), that is, the cir-
cuit breaker is not closed within the preset time,
an alarm signal will be received through con-
tact A.
A blocking voltage applied to the blocking in-
put BS13 (SGB/1=1) over the auxiliary contact
of the miniature circuit breaker prevents the
synchro-check relay from performing the volt-
age-check function when the miniature circuit
breaker trips. It is very important that the volt-
age-check function is prevented by the tripping
of the m.c.b. Unless a blocking signal has been
provided, the synchro-check relay measures the
voltage over this input to be zero and, should
the energizing conditions then correspond to
the setting concerned (SGF/1 and SGF/2), it
gives a close signal to the circuit breaker, when
the command input (push-button depressed) is
active.
U1
U3
I/O
Rx
Tx
Uaux
I
L3
L2
L1
I
62
61
70 71 72
IRF
13
63
14 15 16
17
18 19
20 21
10 11
23
22
47 48
45 46
85
86
87
88
68
69
SGB/1
SGB/2
ALARM
SGR/1
SGR/5
SGR/7
1
IRF
A
B
C
D
CB13
CB23
NC13
CSF13
NC23
CSF23
T1
T2
T3
T4
T5
T6
1
SGR/3
BS13
CS13
BS23
CS23
SGB/4
SGB/3
BS13
BS23
CB13
CB23
U3
U2
SPA-ZC_
X1
X2
X3
SC13
VC13
SC23
VC23
SPAU 140 C
100V
110V
100V
100V
110V
110V
CS13
CS23
SERIAL
PORT
U1
U2
U3