ABB RET615 Product Manual page 34

Transformer Protection and Control
RET615
Product version: 4.0
Protection functions
Table 28. Three-phase non-directional overcurrent protection (PHxPTOC)
Characteristic
Operation accuracy
1)2)
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode
Operate time accuracy in inverse time mode
Suppression of harmonics
1) Set Operate delay time = 0,02 s, Operate curve type = IEC definite time, 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) Includes the delay of the heavy-duty output contact
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PHLPTOC
PHHPTOC
and
PHIPTOC
PHIPTOC:
I = 2 x set Start value
Fault
Start value
I = 10 x set
Fault
PHHPTOC and PHLPTOC:
Start value
I = 2 x set
Fault
Value
Depending on the frequency of the current measured: f
±2 Hz
±1.5% of the set value or ±0.002 x I
±1.5% of set value or ±0.002 x I
(at currents in the range of 0.1...10 x I
±5.0% of the set value
(at currents in the range of 10...40 x I
Minimum Typical
16 ms 19 ms
11 ms 12 ms
22 ms 24 ms
< 40 ms
Typical 0.96
< 30 ms
±1.0% of the set value or ±20 ms
±5.0% of the theoretical value or ±20 ms
RMS: No suppression
DFT: -50 dB at f = n x f , where n = 2, 3, 4, 5,...
n
Peak-to-Peak: No suppression
P-to-P+backup: No suppression
1MRS756891 F
n
n
n
)
n
)
n
Maximum
23 ms
14 ms
25 ms
3)
ABB