Siemens 7SG12 DAD-N - IRIG-B Time Synchronisation; Protection Elements; Common Performance; 87;50-1, 87;50-2 Differential

7SG12 DAD N Performance Specification
©2010 Siemens Protection Devices Limited Chapter 2 Page 7 of 7
4.10 IRIG-B Time Synchronisation
The relay incorporates an IRIG-B time synchronisation port as standard for connection to a GPS time receiver.
The input accepts an a.c. modulated input signal that should be in the range 3Vp-p or 6Vp-p.
5. Protection Elements
5.1 Common Performance
Disengaging Time 30ms
Note: Output contacts have a default minimum dwell time of 100ms, which may be altered via a setting, after
which the disengaging time is as above.
5.2 87/50-1, 87/50-2 Differential
Phase segregated High impedance Overall Differential scheme using external stabilizing resistors. Function is
insensitive to third harmonic currents.
Pickup
± 5% of setting or ± 0.01 I
n
whichever is the greater
Reset  95% of I
s
Repeatability ± 2%
Transient Overreach 5%
Operate Time
2 x Setting
4 x Setting
Operate Time
1 cycle
< 1 cycle
Time Delay
± 1% or ± 5ms
whichever is the greater
5.3 CT-50 CT Supervision
Pickup
± 5% of setting or ± 0.01 I
n
whichever is the greater
Reset  95% of I
s
Repeatability ± 2%
Transient Overreach 5%
Operate Time
2 x Setting
Operate Time
< 1.5 cycles
Time Delay Time Delay setting +/- 5% or +/- 10 milliseconds, whichever is the greater**
**NB: - Minimum Time Delay setting is 100milliseconds
5.4 Trip Circuit Supervision
Time Delay
± 1% or +0, +20 ms
whichever is the greater