The SITOP SEL1200 4-channel selectivity module brings fast-acting electronic circuit protection to 24V DC distribution, with each of its four outputs adjustable from 2A to 10A. Its switching characteristic disconnects overloaded branches decisively — in as little as 30ms for heavy overloads — while the remaining channels stay live.

Switching Characteristic and Tripping Behavior

The inverse-time switching response tolerates brief transients: a 2× overload trips in ~30ms, a 1.5× overload in ~1s, and a mild 1.0× overload may run for up to 5s before shutdown. This curve is designed to ride through inrush events from capacitive loads while still protecting wiring against sustained overcurrent. Two adjacent outputs can be paralleled for loads drawing up to 50% more than a single channel rating.

Designed for Higher-Power Loads

With a 10A ceiling per channel and four channels fed from a 40A input, this module is optimized for fewer but more power-hungry 24V loads — think banks of pneumatic solenoid valves, servo drive logic supplies, or large HMI panels. The adjustable threshold lets engineers match each channel to the connected load's actual consumption rather than a coarse fixed rating.

Installation and Diagnostics

Push-in terminals speed up panel wiring; the 45mm-wide DIN-rail housing fits crowded cabinets. Each channel has a manual reset button, a three-color LED, and accepts a remote reset signal (24V DC, >15V high). A common signaling contact flags faults to a supervisory PLC. Free SIMATIC S7 function blocks are available for per-channel diagnostics over the monitoring interface.