The ABB S202P-Z16 is a 2-pole miniature circuit breaker from the System Pro M compact S200 series, rated 16 A with a Z-curve trip characteristic and a voltage rating of 480Y/277 V AC. The Z-curve is designed for sensitive electronic loads — it trips between 2.5x and 4x In, which means it catches short-circuit faults faster than a B- or C-curve while still tolerating the small inrush of a switching power supply or PLC input bank. On a 480Y/277 V wye system, each pole sees 277 V line-to-neutral, so this breaker is sized for the phase-to-neutral fault path in a 3-phase panel.
The Z-curve's lower magnetic threshold means it coordinates with downstream semiconductor protection fuses or sensitive RCDs more predictably than a C-curve would — useful when the load side includes rectifiers or active front ends.