Temperature Monitoring on DIN Rail — 24 VAC/DC Supply, Solid-State Trip
The Omron K8DT-TH1TD is a temperature monitoring relay from the K8DT series, designed for NPN transistor or RTD inputs with a solid-state output. It operates on 24 VAC/DC and mounts directly to DIN rail, with an operating temperature range of -20°C to 60°C. The relay has no built-in delay — response is essentially instantaneous, which matters when you need rapid fault isolation in a temperature protection loop. The solid-state output (NPN circuit) sinks current rather than switching a dry contact, so plan for a pull-up resistor or match to a compatible PLC input module.
Mounting and Wiring
DIN-rail enclosure; unit is packaged as a box (not a open-frame module). The 24 VAC/DC supply can share a common bus with other K8DT units — verify polarity consistency on DC if mixing supplies. Terminal identification follows Omron’s standard: check the profile drawing on the housing before landing wires.