4NO+4NC contactors

4NO+4NC

— eight independent contact groups: four normally open (NO) and four normally closed (NC). In the default state, NO contacts do not conduct, but they close when activated; NC contacts, on the other hand, always conduct and open when activated. Therefore, a single device can simultaneously turn on some circuits and turn off others. Compared to a configuration with only NO or only NC, the 4NO+4NC option is more convenient for complex control logic and signaling: you can create interlocks, "latching," status indication, and backup circuits without additional relays, although the module itself is usually larger and more expensive. Example of use: in an automation cabinet, four NO's activate several loads/control circuits, while four NC's simultaneously remove power from an alternate mode and send a signal to the controller or a "fault/stop" lamp.