BE1-951
Protection and Control
4-31
blocking control as determined by the logic expression assigned to the BLK input. Auxiliary
under/overvoltage logic settings are summarized in Table 4-22.
Table 4-22. Auxiliary Under/Overvoltage Logic Settings
Function
Range/Purpose
Default
mode
0 = Disabled
1 = Fundamental Vx input
2 = 3Vo Phase Inputs
3 = 3
rd
harmonic, Vx input
0
BLK logic
Logic expression that disables function when
TRUE. A setting of 0 disables blocking.
0
Note: To use mode 2, the VTP connection must be 4-wire. Optional Auxiliary input must be
present to use mode 1 or mode 3.
SL-59X/159X and SL-27X Command
Purpose:
Read or set logic for the neutral overvoltage element.
Syntax:
SL-<x>59X[=<mode>,<BLK logic>]
SL-27X[=<mode>,<BLK logic>]
Comments: See Table 4-22 for settings information.
x=1 for 159X and nothing for 59X
SL-59X Command Example
1.
Enable auxiliary overvoltage protection for three-phase residual voltage (3V
0
) and disable function
blocking.
>SL-59X=2,0
Operating Settings for the Auxiliary Under/Overvoltage Element
Operating settings for the 27X and 59X/159X functions consist of pickup and time delay values. The pickup
value determines the level of voltage required for the element to start timing toward a trip. Unit of measure
is secondary volts (PP or PN) and depends on the SG-VTX setting see table 4-23. For more information,
refer to Section 3,
Input and Output Functions, Voltage Inputs. The time delay value determines the length
of time between pickup and trip. Time delays can be set in milliseconds, seconds, or cycles. The default is
milliseconds if no unit of measure is specified. A time setting of zero makes the element instantaneous with
no intentional time delay. Settings are made using the S<g>-27X or S<g>-<x>59X commands. These
settings can also be viewed or changed at the front panel HMI using screen 5.x.3.2, where x equals 1 for
setting group 0, 2 for setting group 1, 3 for setting group 2, and 4 for setting group 3. Auxiliary undervoltage
and overvoltage operating settings are summarized in Table 4-24.
Table 4-23. VTX Connection Settings
VTX
Connection
Mode
Unit
AB, BC, CA
1 or 3
VPP
AN, BN, CN
1 or 3
VPN
GR
1 or 3
VPN
Don’t Care
2
VPN
