4.5.1.11 Technical data
Table 789: PHPTOV Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the measured voltage:
f
n
±2 Hz
±1.5% of the set value or ±0.002 × U
n
Start time
1, 2
U
Fault
= 1.1 × set
Start value
Minimum Typical Maximum
23 ms 27 ms 31 ms
Reset time Typically 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
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
4.5.2 Three-phase undervoltage protection PHPTUV (ANSI 27)
4.5.2.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Three-phase undervoltage protec-
tion
PHPTUV 3U< 27
4.5.2.2 Function block
Figure 483: Function block
4.5.2.3 Functionality
The three-phase undervoltage protection function PHPTUV is used to disconnect
from the network devices, for example electric motors, which are damaged when
subjected to service under low voltage conditions. PHPTUV includes a settable value
1
Start value
= 1.0 × U
n
, Voltage before fault = 0.9 × U
n
, f
n
= 50 Hz, overvoltage 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
3
Maximum
Start value
= 1.20 × U
n
,
Start value
multiples in range of 1.10...2.00
Protection functions 1MRS759142 F
858 REX640
Technical Manual
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