Table 28. Non-directional earth-fault protection (EFxPTOC)
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: f
n
±2 Hz
EFLPTOC
±1.5% of the set value or ±0.002 x I
n
EFHPTOC
and
EFIPTOC
1)
±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
)
Start time
2)3)
Minimum
Typical
Maximum
EFIPTOC:
I
Fault
= 2 x set
Start value
I
Fault
= 10 x set
Start value
16 ms
11 ms
19 ms
12 ms
23 ms
14 ms
EFHPTOC and EFLPTOC:
I
Fault
= 2 x set
Start value
22 ms
24 ms
25 ms
Reset time
< 40 ms
Reset ratio
Typical 0.96
Retardation time
< 30 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
4)
Suppression of harmonics
RMS: No suppression
DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,…
Peak-to-Peak: No suppression
1)
Function not included.
2)
Measurement mode = default (depends on stage), current before fault = 0.0 x I
n
, f
n
= 50 Hz, earth-fault current with nominal frequency injected from
random phase angle, results based on statistical distribution of 1000 measurements
3)
Includes the delay of the signal output contact
4)
Maximum
Start value = 2.5 x I
n
,
Start value multiples in range of 1.5 to 20
Busbar and Multipurpose Differential Protection and Control
1MRS757467 B
REB611
Product version: 1.0
ABB
21
