Section 4 1MAC309294-MB F
Protection functions
170 RER620
Technical Manual
4.1.4.13 Technical data
Table 182: 67/51N and 67/50N Technical data
4.1.5 Sensitive earth-fault protection 50SEF
4.1.5.1 Identification
Characteristic Value
Operation accuracy Depending on the frequency of the current
measured: f
n
±2Hz
67/51N and 67/50N-1 Current:
±1.5% of the set value or ±0.002 x I
n
Voltage
±1.5% of the set value or ±0.002 x V
n
Phase angle:
±2°
67/50N-2 Current:
±1.5% of the set value or ±0.002 x I
n
(at currents in the range of 0.1…10 x I
n
)
±5.0% of the set value
(at currents in the range of 10…40 x I
n
)
Voltage:
±1.5% of the set value or ±0.002 x V
n
Phase angle:
±2°
Pickup time
1,2
1. Measurement mode = default (depends on stage), current before fault = 0.0 x I
n
, f
n
= 60 Hz, ground-fault
current with nominal frequency injected from random phase angle, results based on statistical distribution of
1000 measurements
2. Includes the delay of the signal output contact
Minimum Typical Maximum
67/50N-2 and 67/51N
and 67/50N-1:
I
Fault
= 2 x set
Pickup
value
61 ms 64 ms 66 ms
Reset time < 40 ms
Reset ratio Typical 0.96
Retardation time < 30 ms
Trip time accuracy in definite time mode ±1.0% of the set value or ±20 ms
Trip time accuracy in inverse time mode
±5.0% of the theoretical value or ±20 ms
3
3. Maximum Pickup value = 2.5 x I
n
, Pickup value multiples in range of 1.5 to 20
Suppression of harmonics RMS: No suppression
DFT: -50dB at f = n x f
n
, where n = 2, 3, 4, 5,…
Peak-to-Peak: No suppression
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Non-directional sensitive earth-fault
protection
XEFLPTOC I
0
> 50SEF