Schweitzer Engineering Laboratories SEL-387E - Optoisolated Inputs

Date Code 20080110 Control Logic 4-1
SEL-387E Instruction Manual
SECTION 4: CONTROL LOGIC
This section explains the settings and operation of:
Optoisolated inputs (IN101–IN106, IN201–IN208)
Output contacts (OUT101–OUT107, ALARM, OUT201–OUT212)
Remote control switches (Remote Bits RB1 through RB16)
Multiple setting groups (Group switching settings SS1 through SS6)
SEL
OGIC
®
Control Equation
Sets (1 through 3) Variables (Timed Variables and Latch Bits)
LED Targeting Logic
Trip and Close Logic
SEL
OGIC control equations (General Discussion)
Relay Word bits
The above items constitute the principal logic functions of the relay. While the protective
elements (overcurrent elements and differential elements) have fixed internal logic, the
availability of Relay Word bits and the use of SEL
OGIC control equations for many of the relay
settings permit the user to customize how the protection functions interface with the user’s
control schemes and overall philosophy of operation.
Relay Word bits and SEL
OGIC control equation settings examples are used throughout this
section. A complete listing of the Relay Word and explanation of the bit names are included at
the end of this section, along with a discussion of SEL
OGIC control equations in general.
O PTOISOLATED I NPUTS
Relay Word bits IN101–IN106 and IN201–IN208 (interface board) follow the states of the
optoisolated level-sensitive inputs having the same names. To assert an input, apply rated
control voltage to the appropriate terminal pair. As noted in Section 1: Introduction and
Specifications and Section 2: Installation, these inputs have a specific voltage range for
operation, and a dropout voltage value below which the input will deassert. The inputs are not
polarity sensitive; either terminal can be positive, the other negative.
Input Functions
There are no
optoisolated input settings such as:
IN101 =
IN102 =
Optoisolated inputs receive their function by how their corresponding Relay Word bits are used
in SEL
OGIC control equations. Remember that any input Relay Word bit name will always
appear on the right side of any SEL
OGIC control equation, as shown below.