6-20
Reporting and Alarm Functions
BE1-951
Figure 6-3. TCM With Other Devices
In Figure 6-3, a 62x auxiliary relay is shown. In this case, the impedance of the 62x coil is small compared
to the impedance of the TCM circuit so the TCM is always at logic 1. This prevents the TCM logic from
working, even if the trip coil is open. Normally, when redundant systems are used, each relay system is on
an individual circuit and the sensing input for each relay system is isolated from the tripping circuit. The
impedance of the TCM circuit is the same as the contact sensing inputs. See Section 1,
General
Specifications, Control Inputs, for this information.
FAULT REPORTING
The fault reporting function records and reports information about faults that have been detected by the
relay. The BE1-951 provides many fault reporting features. These features include Fault Summary Reports,
Sequence of Events Recorder Reports, Oscillographic Records, and Targets.
Logic expressions are used to define the three conditions for fault reporting. These conditions are Trip,
Pickup, and Logic trigger. Figure 6-1 and Table 6-8 illustrate how each of these logic expressions are used
by the various relay functions. Note that even though BESTlogic expressions are used to define these
conditions, these expressions aren’t included here. Section 7,
BESTlogic Programmable Logic provides
information about using BESTlogic to program the relay.
Trip
Trip expressions are used by the fault reporting function to start logging targets for an event and to record
the fault current magnitudes at the time of trip. The HMI uses the trip expression to seal-in the Trip LED. The
breaker monitoring function uses the trip expression to start counting the breaker operate time.
Pickup
Pickup expressions are used by the fault reporting function to time-stamp the fault summary record, time the
length of the fault from pickup to dropout (fault clearing time), and to control the recording of oscillograph
data. The HMI uses the pickup expression to control the flashing of the Trip LED. A pickup expression is also
used by the setting group selection function to prevent a setting group change during a fault.
Logic
Logic trigger expressions allow the fault reporting function to be triggered even though the relay in not picked
up. A logic trigger expression provides an input to the fault reporting function much as the pickup expression
does. This logic expression is not used by the setting group selection or the HMI.
Fault Reporting Trigger Settings
Trigger settings for fault reports are made using the SG-TRIGGER (settings-general, trigger) command.
Trigger settings for fault reporting are summarized in Table 6-11.
