ABB RET670 Product Manual page 51

ABB
Transformer protection RET670
Pre-configured
Product version: 1.1
Differential protection
Table 23. Transformer differential protection T2WPDIF, T3WPDIF
Function
Operating characteristic
Reset ratio
Unrestrained differential current
limit
Base sensitivity function
Second harmonic blocking
Fifth harmonic blocking
Connection type for each of the
windings
Phase displacement between high
voltage winding, W1 and each of
the windings, W2 and W3. Hour
notation
Operate time, restrained function
Reset time, restrained function
Operate time, unrestrained
function
Reset time, unrestrained function
Critical impulse time
Range or value Accuracy
Adaptable ± 2.0% of Ir for I < Ir
± 2.0% of Ir for I > Ir
> 95% -
(100-5000)% of ± 2.0% of set value
IBase on high
voltage winding
(10-60)% of IBase ± 2.0% of Ir
(5.0-100.0)% of ± 2.0% of Ir
fundamental
(5.0-100.0)% of ± 5.0% of Ir
fundamental
Y or D -
0–11 -
25 ms typically at -
0 to 2 x Id
20 ms typically at -
2 to 0 x Id
12 ms typically at -
0 to 5 x Id
25 ms typically at -
5 to 0 x Id
2 ms typically at 0 -
to 5 x Id
1MRK 504 091-BEN B
Issued: June 2010
51