Generator Paralleling - Frequency Δ Check
Check frequency and voltage difference vs the running bus before closing breaker - the classic paralleling window per IEC 60092-301 / IEEE 45.
Δf
0.20Hz
ΔU
0.91%
Paralleling status
In synchronising window - close
Formula, assumptions, and limits
Incoming slightly faster (Δf ≈ +0.1 Hz) is best - incoming generator picks up load smoothly. Autosync / check-sync relays enforce the same window.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Frequency difference | Hz | synchroscope | |
| Voltage difference | V | dual-voltmeter | |
| Phase angle difference | ° | synchroscope |