MSCDN – MP2A Performance Specification
3.14 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.
4 Protection Elements
4.1 Common Performance
Disengaging Time
Disengaging Time
30ms
Note:
Output contacts have a minimum dwell time of 100ms, after which the disengaging time is as above.
4.2 87/50-x-x Overall Differential
Phase segregated High impedance Overall Differential scheme using external stabilizing resistors. Function is
insensitive to third harmonic currents. Each element with individual Inhibit DO Delay timer (Auxiliary Timer) and
following time delay.
Accuracy
Pickup
100% of setting ± 5% or ± 0.01 I
n
Reset
≥
80% of I
s
Repeatability ±
2%
Transient Overreach
≤ 1
5%
Operate Time
± 1% or ± 10ms
Operating Time
Current Applied
Typical
2 x setting
≤
1.5 cycle
4 x setting
≤
1 cycle
4.3 C1/2 50-x Capacitor Unbalance
Phase segregated Capacitor Unbalance element, whose operate quantity is calculated from the ratio of capacitor
load current and the measured spill current, followed by three identical instantaneous Overcurrent elements with
following time delay
Accuracy
Pickup
100% of setting ± 5% or ± 0.02 I
n
Reset
≥
80% of I
s
Repeatability ±
2%
Operate Time
± 1% or ± 10ms
Operating Time
Current Applied
Typical
2 x setting
1.5 cycles
4 x setting
1 cycle
4.4 50N Cap Bank Phase Unbalance
Derived phase unbalance quantity, from the sum of phase currents, applied to an instantaneous overcurrent element
with following time delay.
Accuracy
Pickup
100% of setting ± 5% or ± 0.01 I
n
Reset
≥
80% of I
s
Repeatability ±
2%
Operate Time
± 1% or ± 10ms
Operating Time
Current Applied
Typical
2 x setting
1.5 cycles
4 x setting
1 cycle
©2011 Siemens Protection Devices Limited
Chapter 2 Page 8 of 13
