Table 36. Transient/intermittent earth-fault protection (INTRPTEF) main settings
Parameter Function Value (Range) Step
Directional mode INTRPTEF 1=Non-directional
2=Forward
3=Reverse
-
Operate delay time INTRPTEF 0.04...1200.00 s 0.01
Voltage start value
(voltage start value
for transient EF)
INTRPTEF 0.005...0.500 pu 0.001
Operation mode INTRPTEF 1=Intermittent EF
2=Transient EF
-
Peak counter limit
(Min requirement for
peak counter before
start in IEF mode)
INTRPTEF 2...20 1
Table 37. Negative phase-sequence overcurrent protection (NSPTOC)
Characteristic
Value
Operation accuracy At the frequency f = f
n
±1.5% of the set value or ±0.002 × I
n
Start time
1)2)
I
Fault
= 2 × set Start
value
I
Fault
= 10 × set Start
value
Typical 23 ms (±15 ms)
Typical 16 ms (±15 ms)
Reset time < 40 ms
Reset ratio Typical 0.96
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)
Suppression of harmonics DFT: -50dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
1)
Operate curve type
= IEC definite time, negative sequence current before fault = 0.0, f
n
= 50Hz
2) Includes the delay of the signal output contact
3)
Maximum Start value = 2.5 × I
n
, Start value multiples in range of 1.5 to 20
Feeder Protection and Control 1MRS756380 A
REF630
Product version: 1.0 Issued: 15.09.2009
34 ABB