dead bus relay In manual synchronization, synchronizing check is the default method: close only when the voltage, frequency, and phase‑angle differences are within preset limits. In backup or special conditions, one side may be de‑energized; the normal synchronizing criteria cannot be satisfied. In these cases, an operator may use dead‑bus closing detection to proceed safely. Device Function (WT‑32 example) On the ODES WT‑32 synchro‑check relay, terminals 7–8 accept a dry, no