GE 745 Instruction Manual page 195

CHAPTER 5: SETPOINTS
5.7 S5 Outputs
5.7.1 Description
5.7.2 Relay Assignments
5.7.3 Introduction to FlexLogic™
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
The S5 OUTPUTS page contains the settings to configure all outputs. The 745 has nine
digital outputs (one solid-state, four trip-rated form A contacts, and four auxiliary form-C
contacts), which are fully programmable from the relay unit, as well using FlexLogic™
equations.
In addition to these outputs, the conditions to trigger a waveform capture (trace memory)
is also programmable using FlexLogic™. A ten parameter equation is provided for this
purpose.
As an alternative to FlexLogic™ programming, the output auxiliary relays can be assigned
directly from the element settings on the relay.
On the relay unit, every protection element settings page has a new setting to configure.
The position of the setting is right between the function and the target settings of the
element configuration. The relays selected from the elements page will be energized only
on the operate condition of the protection element.
This new setting allows the user to assign relays directly to the protection element. The
new settings have a default value for no relays assigned (None).
With the addition of the new setting, output relays can be energized from the protection
element setting OR the FlexLogic™.
As an example, the new setting in the Percent Differential element will look like
SETPOINTS S4 ELEMENTS

FlexLogic™ is a highly flexible and easy-to-use equation format which allows any
combination of protection and monitoring elements, logic inputs, outputs, and timers to be
assigned to any output, using multiple input AND, OR, NAND, NOR, XOR, and NOT Boolean
logic gates. Each digital output can have an equation of up to 20 parameters. Five virtual
outputs are also available, each having an equation containing up to 10 parameters,
whose output can be used as a parameter in any other equation.
A FlexLogic™ equation defines the combination of inputs and logic gates to operate an
output. Each output has its own equation, an equation being a linear array of parameters.
Evaluation of an equation results in either a 1 (= ON, i.e. operate the output), or 0 (= OFF, i.e.
do not operate the output).
The table below provides information about FlexLogic™ equations for all outputs:
DIFFERENTIAL PERCENT DIFFERENTIAL
 
S5 OUTPUTS
PATH:
(section 5.6.3.2).
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