ABB RET670 Product Manual page 50

Transformer protection RET670
Customized
Product version: 1.2
Table 28. Restricted earth fault protection, low impedance REFPDIF
Function
Operate characteristic
Reset ratio
Directional characteristic
Operate time, trip function
Reset time, trip function
Second harmonic blocking
Table 29. 1Ph High impedance differential protection HZPDIF
Function
Operate voltage
Reset ratio
Maximum continuous power
Operate time
Reset time
Critical impulse time
50
Range or value
Adaptable
0.95
Fixed 180 degrees or ± 60 to ±
90 degrees
20 ms typically at 0 to 10 x IdMin
25 ms typically at 10 to 0 x IdMin
(5.0-100.0)% of fundamental
Range or value
(20-400) V
I=U/R
>95%
2
U>Trip /SeriesResistor ≤200 W
10 ms typically at 0 to 10 x U
105 ms typically at 10 to 0 x U
2 ms typically at 0 to 10 x U
1MRK 504 117-BEN D
Accuracy
± 1% of IBase
2% of theoretical operate value (Idiff) if Ibias
>= 1.25 IBase (i.e. sections 2 and 3)
(The above is valid if IBase is equal to the
protected winding rated current).
-
± 1 degree at Ibias = IBase
± 2 degrees at Ibias = 2 * IBase
± 3 degrees at Ibias = 4 * IBase
(The above valid if IBase equal to the
protected winding rated current)
-
-
± 2.0% of I Base
r
Accuracy
± 1.0% of I
r
-
-
-
d
-
d
-
d
ABB