Series Boost (Attachment)
Series Boost Module (Attachment)
(1) Series boost module. (2) Current transformer T2
Series boost keeps self-excited SR4 generators on the line, for approximately 10 seconds, when there is a short in the generating or load circuits. This gives circuit breakers a chance to trip in sequence. When circuit breakers trip in sequence, there is less chance for a loss of power to all of the electrical system.
The series boost module and current transformer (T2) make up the series boost.
Reference: For the most current information on connecting to the primary side of the transformer, see Special Instructions, SELS0071-01.
Voltage sensing and power are applied to the series boost module from the voltage sensing terminals 22 and 24 of the regulator.
When the sensed voltage is within normal limits, an electrical signal is sent to the gate of a triac located in the series boost module. This triac short circuits current transformer (T2). This prevents any series boost during normal operation.
If there is a short circuit that causes the voltage at the regulator sensing terminals to drop to a low value, the control signal to the gate of the triac will be turned off. Current from current transformer (T2) will be rectified and applied directly to exciter stator (L1). This field current will be enough to give at least three times full load current into a short circuit. After approximately ten seconds a timer within the series boost module will again cause a control signal to be applied to the gate of the triac. The triac will short circuit transformer (T2). Current flow to exciter stator (L1) will be zero until the short circuit is corrected.
Remove Voltage Control (Attachment)
Partial View Of Regulator
(1) Potentiometer. (2) Jumper. (3) Regulator.
Generator output voltage level can be controlled from a remote location. This is done by connecting potentiometer (1) between terminals (6 and 7) on voltage regulator (3).
Remove jumper link (2) between terminals (4 and 7) for remote voltage level control.
For acceptable voltage control, the remote mounted potentiometer must be a three turn, 10K ohm ± 5%, with a dielectric strength of 1000 VAC minimum (reference 7C4471).
Wiring to the remote mounted potentiometer (connecting to) must be 18 gauge or smaller. The wire should be 600 volt class with a 90°C insulation.
NOTE: Either the jumper between terminals (4 and 7) or the remote potentiometer between terminals (6 and 7) is required for operation.