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Restriking voltage vs recovery voltage

Short answer

Restriking voltage is the transient high-frequency oscillatory voltage appearing across contacts immediately after arc extinction. Recovery voltage is the steady power-frequency (50 Hz) voltage that remains after transients die out.

What is the difference between restriking voltage and recovery voltage?

Restriking voltage is the high-frequency transient voltage that appears across the CB contacts immediately after the arc is extinguished at current zero. Recovery voltage is the normal-frequency (50 Hz) steady voltage that appears across the contacts after the transient has died out.

 v |      restriking (transient)
   |     /\  /\
   |    /  \/  \/~~~~~~ recovery voltage
   |   /                 (50 Hz, steady)
   |__/__________________ t
     current zero
PointRestriking voltageRecovery voltage
NatureTransient, oscillatorySteady, power frequency
FrequencyNatural frequency 1/(2π√LC), kHz rangeSystem frequency (50 Hz)
TimeFirst few μs to ms after current zeroAfter the transient decays
Peak valueUp to 2 V_m (resistance neglected)About V_m sin φ
Depends onSystem L, C, R and p.f.System voltage and p.f. of fault
EffectIts RRRV decides whether the arc restrikesDecides final dielectric stress on gap

In short, the restriking voltage is the oscillation superimposed on the recovery voltage; the breaker succeeds only if the dielectric strength of the gap rises faster than the restriking voltage.

✓ Answer checked by Claude Opus 5.5 (high effort)

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