Winco DGC-2020 - Manual (Page 60)

3-12 DGC-2020 Functional Description 9400200990 Rev K
Breaker close sources are:
 The DGC-2020 itself when the automatic transfer (ATS) feature is enabled
 The DGC-2020 itself when the Run with Load logic element receives a Start pulse in the
programmable logic.
 The DGC-2020 itself when started from a Demand Start as part of demand start/stop and
sequencing.
 The DGC-2020 itself when started from the Exercise Timer and the Run with Load box is checked in
the Generator Exerciser Settings.
 Manual Breaker Close Input Contacts applied to the Open and Close inputs on the left side of the
Generator Breaker logic element in the programmable logic.
Any of the above close sources will work when the DGC-2020 is in AUTO mode. Only the Manual
Breaker Close Input Contacts can initiate a breaker closure when the DGC-2020 is in RUN mode.
Generator speed can be influenced by either the speed trim function, which is active at all times if
enabled, and the synchronizer. Since the speed trim function can cause some activity on the speed bias
outputs, when performing synchronizer troubleshooting it is recommended that the speed trim function be
disabled.
The best way to tell if the synchronizer is active is to disable the speed trim function, then when it is
desired to synchronize check for raise and/or lower pulses coming from the DGC-2020 if the governor or
AVR bias control output type is contact, or to check the governor and/or AVR bias analog outputs on the
load share module with a volt meter if the governor or AVR bias control output type is analog. The
voltages or raise/lower pulses should be changing when the synchronizer is active. If there are no
raise/lower pulses, or if the analog bias voltages do not change, the synchronizer is not active.
A readily available method of verifying synchronizer operation during initial set up and commissioning is
to connect a light bulb from phase B of the machine being synchronized to phase B of the bus. Three
bulbs, one on each phase can be employed if so desired. The bulb(s) should be off or very dim when it is
OK for the breaker to close.
If the synchronizer does not seem to operate properly, refer to Section 7, Maintenance and
Troubleshooting.
EVENT RECORDING
An event log retains history of system events in nonvolatile memory. Thirty event records are retained
and each record contains a time stamp of the first and last event occurrence, and the number of
occurrences for each event. In addition, each record contains details of the time, date, and engine hours
for the most recent 30 occurrences of the event. The number of occurrences stops incrementing at 99. If
an event occurs which is of a type that differs from those in the 30 records in memory, the record that has
the oldest “last” event occurrence is removed from the log, and the new category takes its place. Since 30
event records with up to 99 occurrences each are retained in memory, a history of nearly 3,000 specific
events are retained in the DGC-2020. Detailed occurrence information is retained for the most recent 30
occurrences of each event record, and there are 30 event records; thus the time, date, and engine hours
details for up to 900 specific event occurrences are retained in the event log.
BESTCOMSPlus can be used to view and/or download the event log. The event log may also be viewed
through the front panel HMI by navigating to Metering, Alarms-Status, Event Log. Use the Up/Down keys
to highlight an event and press the Right key to view the summary of that event record. The summary
contains the description of the event, the date, time, and engine hours of the first occurrence of the event,
along with date, time, and engine hours of the most recent occurrence of the event. To view details of
specific event occurrences, press the Down key until DETAILS is highlighted and then press the Right
key. The occurrence number can be changed by pressing the Edit key, Up/Down keys to select #, and
pressing the Edit key again to exit. Table 3-4 lists all possible event strings (as shown in the event log).