ABB REL650 series, Applications Manual

Page: 264 / 516

operation. If the function shall be insensitive for single phase-to-ground faults 2 out of 3
can be chosen.
Pickupn : Set undervoltage operation value for step n ( n =step 1 and 2), given as % of the
global parameter VBase . This setting is highly dependent of the protection application.
Here it is essential to consider the minimum voltage at non-faulted situations. This voltage
is larger than 90% of nominal voltage.
tn : Time delay for step n ( n =step 1 and 2), given in s. This setting is highly dependent of
the protection application. In many applications the protection function does not directly
trip where there is short circuit or ground faults in the system. The time delay must be
coordinated to the short circuit protection.
t1Min : Minimum operating time for inverse time characteristic for step 1, given in s. When
using inverse time characteristic for the undervoltage function during very low voltages
can give a short operation time. This might lead to unselective trip. By setting
t1Min
longer than the operation time for other protections such unselective tripping can be
avoided.
TD1 : Time multiplier for inverse time characteristic. This parameter is used for
coordination between different inverse time delayed undervoltage protections.
The function must be externally blocked when the protected object is
disconnected.
8.2 Two step overvoltage protection OV2PTOV (59)
8.2.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Two step overvoltage protection OV2PTOV
3U>
SYMBOL-C-2U-SMALLER-THAN
V2 EN
59
Section 8
1MRK 506 334-UUS A
Voltage protection
258
Application manual