Features:
- Three-condition decision: Frequency, phase and voltage are evaluated before breaker closure.
- Commissioning modes: RUN, CHECK, PERMISSIVE and OFF separate testing from automatic operation.
- Adjustable close stability: Dwell selection requires acceptable conditions to persist before the relay acts.
9905-003 is the Woodward SPM-A device used to bring an incoming generator into agreement with an energized bus.
It does more than compare meters: the synchronizer biases the prime-mover control and supervises the close window.
CHECK and PERMISSIVE modes give engineers ways to observe or qualify the decision before granting full automatic breaker closure.
Apter Power can help confirm Woodward 9905-003 voltage class, output interface, operating mode and breaker-control scope before quotation.
9905-003 Manuals, Datasheets, Links
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
- Frequency comparison: Generator speed is guided toward bus frequency.
- Phase comparison: Closure is allowed only inside the selected phase relationship.
- Voltage matching: Generator and bus voltage must satisfy the permitted difference.
- Dwell requirement: Conditions remain acceptable for the selected interval before the close output.
- RUN mode: Enables the full automatic synchronizing sequence.
- CHECK mode: Lets technicians observe operation without a normal breaker-close result.
- PERMISSIVE mode: Provides a synchronism permission within the engineered control scheme.
- OFF mode: Removes synchronizer action during isolated testing or maintenance.
- Close relay: The output must match the breaker control-circuit load.
- Bias output: Output impedance is selected for the connected speed governor interface.
- Polarity control: Reversed generator or bus sensing can invalidate the closing decision.
- Inhibited proof: Sensing and mode behavior are checked before the breaker is allowed to close.
- Generator-to-bus paralleling: Brings an incoming set into a safe close window.
- Multiple-generator plants: Synchronizes another generator to an energized common bus.
- Standby power systems: Supports controlled return or paralleling where the switchgear permits it.
- Legacy synchronizer service: Restores an installed SPM-A function while non-drop-in alternatives are engineered separately.