Section 4
1MAC050144-MB C
Protection functions
230
615 series ANSI
Technical Manual
4.2.1.10
Technical data
Table 228: 59 Technical data
4.2.2
Three-phase undervoltage protection 27
4.2.2.1
Identification
4.2.2.2
Function block
Figure 108:
Function block
4.2.2.3
Functionality
The three-phase undervoltage protection 27 is used to disconnect from the network
devices, for example electric motors, which are damaged when subjected to service under
low voltage conditions. 27 includes a settable value for the detection of undervoltage either
in a single phase, two phases or three phases.
The function contains a blocking functionality. It is possible to block function outputs,
timer or the function itself, if desired.
Characteristic
Value
Pickup accuracy
Depending on the frequency of the voltage
measured: f
n
±2Hz
±1.5% of the set value or ±0.002 x V
n
Pickup time
12
1.
Pickup value
= 1.0 x V
n
, Voltage before fault = 0.9 x V
n
, f
n
= 60 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
Minimum
Typical
Maximum
V
Fault
= 1.1 x set
Pickup
value
22 ms
24 ms
26 ms
Reset time
< 40 ms
Reset ratio
Depends of 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
3. Maximum
Pickup value
= 1.20 x V
n
,
Pickup value
multiples in range of 1.10 to 2.00
Suppression of harmonics
DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,…
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Three-phase undervoltage protection
PHPTUV
3U<
27
Summary of Contents for 615 Series ANSI
Page 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Page 2: ......
Page 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Page 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Page 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Page 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Page 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
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