ABB RET670 Product Manual page 52

Transformer protection RET670
Pre-configured
Product version: 1.1
Table 24. Restricted earth fault protection, low impedance REFPDIF
Function
Operate characteristic
Reset ratio
Base sensitivity function
Directional characteristic
Operate time
Reset time
Second harmonic blocking (5.0-100.0)% of
Table 25. High impedance differential protection (PDIF, 87)
Function
Operate voltage
Reset ratio
Maximum continuous voltage U>TripPickup
Operate time
Reset time
Critical impulse time
52
Range or value
Adaptable
>95%
(4.0-100.0)% of IBase
Fixed 180 degrees or ± 60
to ± 90 degrees
20 ms typically at 0 to 10
x Idiff
25 ms typically at 10 to 0
x Idiff
fundamental
Range or value
(20-400) V
>95%
2
/series resistor
≤200 W
10 ms typically at 0 to 10 x U
90 ms typically at 10 to 0 x U
2 ms typically at 0 to 10 x U
1MRK 504 091-BEN B
Issued: June 2010
Accuracy
± 2.0% of Ir for I < IrBase
r
± 2.0% of I for I > IrBase
-
± 2.0% of I
r
± 2.0 degree
-
-
± 2.0% of I Base
r
Accuracy
± 1.0% of U for U < U
r
± 1.0% of U for U > U
-
-
-
d
-
d
-
d
r
r
ABB