Common Setpoints; Logic Diagrams - GE 339 Instruction Manual

CHAPTER 6: SETPOINTS

Common setpoints

Logic diagrams

339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
Any of these methods can be used to enter the same information. A computer, however,
makes entry much easier. Files can be stored and downloaded for fast, error free entry
when a computer is used. To facilitate this process, the GE EnerVista CD with the EnerVista
SR3 Setup software is supplied with the relay.
The relay leaves the factory with setpoints programmed to default values, and these
values are shown throughout the setpoint message illustrations. Some of these factory
default values can be left unchanged whenever they satisfy the application.
At a minimum, the S2 SYSTEM SETUP
correctly. To safeguard against the installation of a relay into which setpoints have not
been entered, the Relay Not Ready self-test warning is displayed. In addition, the critical
failure relay will be de-energized. Once the relay has been programmed for the intended
application, the S1 RELAY SETUP/ INSTALLATION/ RELAY STATUS
changed from "Not Ready" (the default) to "Ready".
To make the application of this device as simple as possible, similar methods of operation
and similar types of setpoints are incorporated in various features. Rather than repeat
operation descriptions for this class of setpoint throughout the manual, a general
description is presented in this overview. Details that are specific to a particular feature are
included in the discussion of the feature. The form and nature of these setpoints is
described below.
• FUNCTION setpoint: The
operational characteristic of each feature. The range for these setpoints is two or
more of: "Disabled", "Enabled", "Trip", "Alarm", "Latched Alarm", and "Control".
If <ELEMENT_NAME >
If <ELEMENT_NAME >
If <ELEMENT_NAME >
output is generated, the feature declares a Trip condition, and operates the Trip relay
(output relay 1), any other selected aux. output relays, and displays the appropriate
trip message.
If <ELEMENT_NAME>
operational. When an output is generated, the feature declares an "Alarm" condition
which operates any selected aux.output relays and displays the appropriate alarm
message.
• Output Relay * setpoint: The
the relays required to operate when the feature generates an output. The range is any
combination of the assignable Auxiliary relays.
• PICKUP setpoint: The
above which the measured parameter causes an output from the measuring element.
• DELAY setpoint: The <ELEMENT_NAME> DELAY
to delay an input signal from appearing at the output. The time from a contact input
change of state or an AC parameter input level change to a contact closure of the 1
Trip relay, is the time selected as time delay in this setpoint plus approximately up to 2
power frequency periods.
The logic diagrams provide a complete comprehensive understanding of the operation of
each feature. These sequential logic diagrams illustrate how each setpoint, input
parameter, and internal logic is used in the feature to obtain an output. In addition to these
logic diagrams, written descriptions are provided in the setpoints chapter which includes
each feature.
setpoints must be entered for the system to function
<ELEMENT_NAME> FUNCTION
FUNCTION: "Disabled", the feature is not operational.
FUNCTION: "Enabled", the feature is operational.
FUNCTION: "Trip", then the feature is operational. When an
FUNCTION: "Alarm" or "Latched Alarm", then the feature is
<ELEMENT_NAME> OUTPUT RELAY *
<ELEMENT_NAME> PICKUP
setpoint should be
setpoint determines the
setpoint selects
setpoint selects the threshold
setpoint selects a fixed time interval
SETPOINTS
6–3