Dixell Temperature Controller Heat Pump Unit Controller IC121CX-11200

The Dixell IC121CX (also marketed under Copeland and Emerson) is a compact controller tailored for chiller and heat-pump systems, offering comprehensive control over compressor stages, condenser fans, and defrost cycles. 

It supports multiple sensors and output formats, making it ideal for efficient climate control applications in commercial refrigeration and HVAC systems.

Key Features

Model / P/N: IC121CX (various suffixes indicate I/O config)  

Supply Voltage: 12–24 VAC/DC, 5 VA

Sensor Inputs:

2× NTC sensors standard (Pb1/Pb2)

Pb3 configurable: NTC / 4–20 mA / 0–5 V

Optional Pb4 support: NTC or ID devices (e.g., expansion valve feedback)  

Relays:

Up to 5 output relays (8 A each) for compressors, fans, defrost, alarms

Analog/PWM Output:

Built-in 4–20 mA or 0–10 V output for analog control (e.g. variable-speed fans)

PWM control available for smooth modulation  

Display & Interface:

Two-line digital display with front-panel pushbuttons (“Hot Key” programming)  

Additional Functions:

Real-time clock for time-based defrost/energy cycles

Event logging (alarms/data history)

Mounting & Dimensions: 32×74 mm panel cut-out, 60 mm depth, IP65 front protection