GE 750 Instruction Manual page 20

750/760
Feeder Management Relay
1–12
the same time, to energize one, a combination, or all five auxiliary relays during
the process.
• Define if the output relays will be set as fail-safe type.
• Define if the 750/760 will be used to close the breaker. If that will be the case,
gather information on the conditions that will be used to verify synchronism.
• Define if the relay will be used to monitor the status of the breaker. It is strongly
recommended that the 750/760 always be programmed to monitor breaker sta-
tus by means of a digital input connected to the one of the 750/760 logic inputs.
Use an auxiliary contact from the breaker either a normally open contact, 52a,
which is normally in open position when the breaker is open, or a normally
closed contact, 52b, which is in closed position when the breaker is open. A
combination of both can also be utilized, adding the capability for monitoring
pole discrepancy, an indication of a potential mechanical problem within the
main contact mechanism of the breaker.
• If the relay will be used to respond to logic inputs, prepare a list including:
– logic input name
– condition by which the logic input would be considered asserted
– function that the logic input will initiate within the 750/760.
• If the relay will be used to perform Monitoring functions and act upon certain
conditions, gather information such as:
– minimum and maximum values
– alarm and trip values
– time delays
– demand method to be used
– breaker timings
• It is important to familiarize yourself with the relay control functions before set-
ting up the relay. Some control functions such as the Transfer scheme, which
takes automatic control of the auxiliary outputs, or the autorecloser that uses
the auxiliary outputs for specific pre-defined functions, can have an unwanted
effects in the performance of other functions within the relay.
To start, simply power on the unit, and follow the instructions in this tutorial. The
example assumes the following system characteristics. It also assumes that relay
setpoints are unaltered from their factory default values.
Refer to the following figures for schematics related to this application example.
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Application Example
GE Multilin