Hitachi Relion 670 Series Product Manual page 115

Line differential protection RED670
Version 2.2
The healthy condition close to the rated
values (that is, V/Hz below the set pickup
value) must be applied first when the
operate time of a function is tested.
Otherwise, an additional delay of up to 50
ms should be added to stated operate
times.
Table 79. Voltage differential protection VDCPTOV
Function
Voltage difference for alarm and trip
Under voltage level
Independent time delay for voltage differential
alarm at 0.8 x UDAlarm to 1.2 x UDAlarm
Independent time delay for voltage differential
trip at 0.8 x UDTrip to 1.2 x UDTrip
Hitachi Energy
Range or value
(2.0–100.0) % of UBase
(1.0–100.0) % of UBase
(0.000–60.000)s
(0.000–60.000)s
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Accuracy
±0.5% of U
r
±0.5% of U
r
±0.2% or ±40 ms whichever is greater
±0.2% or ±40 ms whichever is greater
1MRK 505 379-BEN R
SEMOD166919-2 v7
115