Basler Electric BE1-25A - Manual (Page 82)

The discriminator output is modified by the stability circuit (controlled by the front panel STABILITY
control) to produce the proper polarity signal for correcting the generator frequency. Unless inhibited by a
dead bus or by a 52b relay contact signal input, the stability output is amplified and delivered to a
summing point type governor. Note that a bump pulse is issued only when the generator is frequency
matched but not phase matched.
A dead bus condition or 52b auxiliary contact closure causes the module outputs to go to zero volts.
Figure 6-13. Module F2 Block Diagram
Frequency Matching Module F4
(See Figure 6-14.) If the bump pulser circuit does not receive the 180 ° out-of-phase signal before the
adjustable interval has timed out, a bump pulse (whose width is determined by the front panel BUMP
PULSE WIDTH control) is output to the gates to change the generator speed slightly to decrease the
phase angle.
The bump pulser signal, together with the frequency low or frequency high signal, is input to the gate.
Unless disabled by a slip frequency inhibit signal, the gates will then generate an output to the
discriminator.
The discriminator output is modified by the stability circuit (controlled by the front panel STABILITY
control) to produce the proper polarity signal for correcting the generator frequency. Unless inhibited by a
dead bus or by a 52b relay contact signal, the stability output is amplified and then delivered to the offset
amplifier. Note that a bump pulse issued only when the generator is frequency matched but not phase
matched.
The offset amplifier adds the offset (adjustable by the front panel OFFSET control) to the correction
signal, and outputs the result to a summing point type governor.
A dead bus condition or 52b auxiliary contact closure causes the module outputs to go to zero volts.
6-12 BE1-25A Relay Differences 9146600990 Rev S