Siemens SIPROTEC 7SJ80

[prinzip-ausloesekreisueberwachung-1-binein-150502-kn, 1, en_US]
Figure 3-2
Trip circuit supervision with one binary input
This results in an upper limit for the resistance dimension, R
max
and a lower limit R
min
, from which the optimal
value of the arithmetic mean R should be selected:
[formel-mittelwert-r-260602-kn, 1, en_US]
In order that the minimum voltage for controlling the binary input is ensured, R
max
is derived as:
[formel-rmax-260602-kn, 1, en_US]
So the circuit breaker trip coil does not remain energized in the above case, R
min
is derived as:
[formel-rmin-260602-kn, 1, en_US]
Ι
BI (HIGH)
Constant current with activated BI ( = 0.4 mA)
V
BI min
Minimum control voltage for BI (= 19 V at delivery setting for nominal voltages of 24 V/ 48 V;
88 V at delivery setting for nominal voltages of 60 V/ 110 V/ 125 V/ 220 V/ 250 V)
V
CTR
Control voltage for trip circuit
R
CBTC
Ohmic resistance of the circuit breaker coil
V
CBTC(LOW)
Maximum voltage on the circuit breaker coil that does not lead to tripping
If the calculation has the result
max
< R
min
, the calculation has to be repeated with the next smaller threshold
V
BI min
. This threshold is determined via the parameters 220 Threshold BI 1 to 226 Threshold BI 7. The
settings Thresh. BI 176V, Thresh. BI 88V, Thresh. BI 19V are possible.
Mounting and Commissioning
3.1 Mounting and Connections
314 SIPROTEC 4, 7SJ80, Manual
E50417-G1140-C343-A8, Edition 12.2017