Section 4 1MAC309294-MB F
Protection functions
206 RER620
Technical Manual
4.3.2.10 Technical data
Table 216: 27 Technical data
4.3.3 Zero sequence overvoltage protection 59N
4.3.3.1 Identification
4.3.3.2 Function block
Figure 93: Function block
4.3.3.3 Functionality
The zero sequence overvoltage protection 59N is used in distribution networks where the
zero sequence overvoltage can reach non-acceptable levels in, for example, high
impedance grounding.
The function picks up when the zero sequence voltage exceeds the set limit. 59N operates
with the definite time (DT) characteristic.
The function contains a blocking functionality. It is possible to block function outputs, the
definite timer or the function itself, if desired.
Characteristic Value
Operation accuracy Depending on the frequency of the voltage
measured: fn ±2Hz
±1.5% of the set value or ±0.002 x V
n
Pickup time
12
1. Pickup value = 1.0 x V
n
, Voltage before fault = 1.1 x V
n
, f
n
= 60 Hz, undervoltage in one phase-to-phase 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
V
Fault
= 0.9 x set
Pickup
value
62 ms 64 ms 66 ms
Reset time < 40 ms
Reset ratio Depends on the set
Relative hysteresis
Retardation time < 35 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
Operate time accuracy in inverse time mode
±5.0% of the theoretical value or ±20 ms
3
3. Minimum Pickup value = 0.50, Pickup value multiples in range of 0.90 to 0.20
Suppression of harmonics DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,…
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Zero sequence overvoltage protection ROVPTOV U0> 59N
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