5-2
BE1-25A Testing
9146600990 Rev M
sidebands (or jitter) ex ceed the MAX SLIP frequency , ov ershoot and prolonged delay in rec losing will
likely oc cur.
•
Because installations may have different characteristics, there is no standard value for the generator
speed correction pulse width and interval settings. Refer to the following paragraph
Maximizing Auto-
Synchronizer Performance
for a recommended procedure to achieve values for the generator speed
correction pulse width and interval settings.
•
Whenever the LOAD switch is raised, the BE1-25A becomes inactive (non-functional) for 1.0 second.
Maximizing Auto-Synchronizer Performance
Disconnect the breaker from the Auto-Synchronizer output. Se lect a pulse width and interval setting based
on governor sensitivity. Record the synchronizing time (that time from when the Auto-Synchronizer initiates
correction pulses to wh en the Auto-Sy nchronizer issues the breaker close s ignal).
If excessive overshooting occurs, reduce the correction pulse wid th and increase the correctio n pulse interval.
If the generator speed increases too slowly, then increase the correction pulse width and reduce the correction
pulse interval.
Maximum performance is achieved if synchronization occurs within one to two minutes providing that the Auto-
Synchronizer takes control of the generator within a two hertz slip frequency window.
APPLICATION EXAMPLE
Exa m ple P aram eters
•
A generator breaker whose characteristic closing time is 385 milliseconds.
•
A m aximum allowable slip ra te of 0.1 hertz. (This slip rate suggests that our hy pothe tica l generator is
of gre ater than a verage size.)
•
A generator undervoltage of 65 Vac. (I.e., at this voltage or below, no effort shall be made by the Auto-
Synch ronizer to c ontro l the ge nera tor vo ltage.)
•
For this example, the generator is designated West. This generator breaker closing time is to be
stored as generator breaker 2 in the Auto-Synchronizer memory.
Rec om m end ed P roce du re
Step 1.
Bring the memory register for the test generator into view by depressing the FUNCTION switch
once (MCU display should show 0 in the left-most digit and—in the right-most digit), and then
depress the increment switch twice to select generator breaker 2 (MCU display shows 2 in the righ t-
mos t digit).
Step 2.
Depress the FUNC TION switch once and observe that the display left-most digit shows 1. Change
the display to read 1.385, the .385 represents th e new bre aker-closing time in seconds. T his is
done by holding and/or stepping the INCRE MENT /DECREM ENT switch until the desired number
is displayed. (Note the two-speed re sponse as the sw itch is held depressed. T his feature greatly
speeds up the selection process.) Raise the LOAD switch, and hold it raised for at least two
seconds. The display will blank out and then, after about one se con d, will read 1.3 85. T his is to
acknowledge that the characteristic closing time for the breaker that controls the West generator
has been recorded.
Step 3.
Depress the FUNCTION switch once and observe that the display left-most digit shows 2. Use the
INCREMENT/DECREMENT sw itch to select a value/setting for the correction pulse width. Raise
the LOAD sw itch, and hold it raised for about two seconds. The display will blank out and then
return, indicating that the new correction pulse width has been stored in MCU memory.
Step 4.
Depress the FUNCTION switch once and observe that the display left-most digit shows 3. Use the
INCREMENT/DECREMENT switch to select a value/setting for the correction pulse interval. Raise
the LO AD sw itch , and hold it rais ed for about two seconds. Th e display will blank out and then
return, indicating that the new correction pulse interval has been stored in MCU memory.
Step 5.
Depress the FUNCTION SELECT switch twice to cause the figure 4 to appear as the left-most digit
of the display. As indicated on the front panel chart, this is the reg iste r that s tores the maximum slip
rate. Using the INCREMEN T/DECREM ENT switch, adjust the display digits to read .100, then raise
the LOAD sw itch and hold it raised for about two seconds until the display goes from blank to 4
.100. The maximum slip rate is now loaded.
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