Protection functions
Table 24. Three-phase non-directional overcurrent protection (PHxPTOC)
Operation
accuracy
Depending on the frequency of the current measured: f
n
±2Hz
PHLPTOC ±1.5% of the set value or ±0.002 x I
n
PHHPTOC
and
PHIPTOC
±1.5% of 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
1) 2)
Minimum Typical Maximum
PHIPTOC:
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
PHHPTOC and PHLPTOC:
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
3)
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
P-to-P+backup: No suppression
1) Measurement mode = default (depends on stage), current before fault = 0.0 x In, fn = 50 Hz, fault current in one
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
3) Maximum Start value = 2.5 x In, Start value multiples in range of 1.5 to 20
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