ABB RET670 Product Manual page 68

Transformer protection RET670
Customized
Product version: 1.2
Frequency protection
Table 62. Underfrequency protection SAPTUF
Function
Operate value, start function
Operate time, start function
Reset time, start function
Operate time, definite time function
Reset time, definite time function
Voltage dependent time delay
Exponent
é - ù
U UMin
(
= ×
t tMax tMin
ê ú
ë - û
UNom UMin
EQUATION1182 V1 EN
U=U
measured
Table 63. Overfrequency protection SAPTOF
Function
Operate value, start function
Operate time, start function
Reset time, start function
Operate time, definite time function
Reset time, definite time function
Table 64. Rate-of-change frequency protection SAPFRC
Function
Operate value, start function
Operate value, internal blocking level
Operate time, start function
68
Range or value
(35.00-75.00) Hz
100 ms typically
100 ms typically
(0.000-60.000)s
(0.000-60.000)s
Settings:
UNom=(50-150)% of U
UMin=(50-150)% of U
)
- +
tMin
Exponent=0.0-5.0
tMax=(0.000-60.000)s
(Equation 4)
tMin=(0.000-60.000)s
Range or value
(35.00-75.00) Hz
100 ms typically at f
100 ms typically
(0.000-60.000)s
(0.000-60.000)s
Range or value
(-10.00-10.00) Hz/s
(0-100)% of UBase
100 ms typically
1MRK 504 117-BEN D
Accuracy
± 2.0 mHz
-
-
± 0.5% ± 10 ms
± 0.5% ± 10 ms
5% + 200 ms
base
base
Accuracy
± 2.0 mHz at
symmetrical three-
phase voltage
-0.5 Hz to f +0.5 Hz -
set set
-
± 0.5% ± 10 ms
± 0.5% ± 10 ms
Accuracy
± 10.0 mHz/s
± 0.5% of U
r
-
ABB