Schweitzer Engineering Laboratories SEL-421-4, Instruction Manual

Page: 275 / 1518

5.115
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Over- and Undervoltage Elements
E27 (Enable Undervoltage Elements)
Select the number of undervoltage elements (1–6) you require for your
application.
27O
n
(Undervoltage Element Operating Quantity)
Select the desired operating quantity for each voltage terminal from Table 5.66 .
27P
n
P1 (Undervoltage Level 1 Pickup)
Set pickup values for the voltage values below that you want the Level 1 under-
voltage elements to assert.
27P
n
P2 (Undervoltage Level 2 Pickup)
Set pickup values for the voltage values below that you want the Level 2 under-
voltage elements to assert.
27TC
n
(Undervoltage Torque Control)
Use the torque-control setting to specify conditions under which the undervoltage
elements must be active. There is only one setting for both Level 1 and Level 2
elements. With the default setting equal to 1, both levels are active permanently.
Setting Prompt Range Default Category
E27 Enable Undervoltage Elements N, 1–6 N Group
Setting Prompt Range Default Category
27O n
a
a
n = 1–6.
U/V Element n Operating Quantity See Table 5.66 V1FIM Group
Setting Prompt Range Default Category
27P n P1
a
a
n
= 1–6.
U/V Element n Level 1 P/U 2.00 to 300 volts, sec. 20 Group
Setting Prompt Range Default Category
27P n P2 U/V Element n Level 2 P/U 2.00 to 300 volts, sec. 15 Group
Setting Prompt Range Default Category
27TC n
a
a
n = 1–6.
U/V Element n Torque Control
(SEL
OGIC
Equation)
SEL
OGIC
Equation 1 Group