Schneider Electric S33681 Time Delay Switch Unit is an external time‑delay module that attaches to undervoltage release (UVR) circuits in Square D breakers, including MasterPact NT/NW and PowerPact J, H, M, P, R, L frames (and compatible ComPacT NS families). It offers an adjustable delay from 0.5 to 3 seconds and accepts a control voltage of 100–130 V AC or DC, with AC operation at 50/60 Hz. Sold as a dedicated spare part by Schneider Electric, the S33681 mounts externally to the breaker to extend UVR timing control and coordinate tripping behavior without replacing the main breaker package.
