084B8520
by Danfoss
The 084B8520 electronic climate controller is produced by Danfoss within the Electronic Climate Controllers series. It serves as a dedicated control node for compact refrigeration and HVAC installations used in automated food storage, process cooling, and building comfort systems. By coordinating compressor cycling, evaporator demand, and safety interlocks, the device maintains stable temperatures while exchanging supervisory data with higher-level automation networks.
The controller is energized from a single-phase 230 V supply, and its logic draws only 2.5 VA, so it adds minimal load to a control panel transformer. Four onboard relay contacts (4) can be assigned to compressors, fans, heaters, or alarm circuits. Serial connectivity through MODBUS is included, and an optional LON interface supports building-automation platforms. An independent alarm output notifies remote systems of sensor faults or excessive temperature. Temperature feedback inputs accept NTC-M2020, PTC 1000, and Pt 1000 probes for accurate measurement across typical refrigeration ranges.
Capacity control logic can stage up to 2 compressors for load matching while supervising a single evaporator path (1) to streamline piping in compact systems. The enclosure weighs only 0.26 kg, allowing DIN-rail or panel mounting without extra cabinet reinforcement. When paired with an NTC-M2020 sensor the unit benefits from fast thermal response, supporting tighter set-point control during frequent door openings or rapid product loading. Combined with modest power draw and multiple relay channels, the controller promotes efficient refrigeration operation inside distributed automation architectures.
