ABB RET615 Product Manual page 40

Transformer Protection and Control
RET615
Product version: 4.0
Table 38. Three phase undervoltage protection (PHPTUV)
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
Start value = 1.0 x U
1) , Voltage before fault = 1.1 x U
n
phase angle, results based on statistical distribution of 1000 measurements
2) Includes the delay of the signal output contact
3) Minimum Start value = 0.50, Start value multiples in range of 0.90 to 0.20
Table 39. Three-phase undervoltage protection (PHPTUV) main settings
Parameter
Start value
Time multiplier
Operate delay time
1)
Operating curve type
1) For further reference please refer to the Operating characteristics table
Table 40. Thermal overload protection, two time constants (T2PTTR)
Characteristic
Operation accuracy
1)
Operate time accuracy
1) Overload current > 1.2 x Operate level temperature
40
U = 0.9 x set Start value
Fault
, f = 50 Hz, undervoltage in one phase-to-phase with nominal frequency injected from random
n n
Function
PHPTUV
PHPTUV
PHPTUV
PHPTUV
Value
Depending on the frequency of the voltage measured: fn
±2 Hz
±1.5% of the set value or ±0.002 x U
Minimum Typical
62 ms 64 ms
< 40 ms
Relative hysteresis
Depends on the set
< 35 ms
±1.0% of the set value or ±20 ms
±5.0% of the theoretical value or ±20 ms
DFT: -50 dB at f = n x f , where n = 2, 3, 4, 5,...
n
Value (Range)
0.05...1.20 x U
n
0.05...15.00
60...300000 ms
Definite or inverse time
Curve type: 5, 15, 21, 22, 23
Value
Depending on the frequency of the current measured: f
±2 Hz
Current measurement: ±1.5% of the set value or ±0.002
x I (at currents in the range of 0.01...4.00 x I
n
±2.0% of the theoretical value or ±0.50 s
1MRS756891 F
n
Maximum
66 ms
3)
Step
0.01
0.01
10
n
)
n
ABB