Carel

IR33W7HR20

IR33+ Series • Refrigeration Controller

Type Refrigeration

Application Cold Room

Probe Inputs 4

Relay Outputs 4

Communication RS485 Modbus

Panel Size 71x29 mm

R1 Compressor

R2 Defrost

R3 Fan

R4 Auxiliary

Advanced universal controller with extended features and connectivity

Technical Specifications

Display Type	LED
Display Digits	4
Buttons	4
LED Indicators	Compressor, Defrost, Fan, Alarm, Aux

Relay Outputs	4
Relay Rating	8A/250VAC

Operating Temp	-10 to 60°C
Storage Temp	-20 to 70°C

Terminal	Function	Type	Wire Color
L	Power L	Input	brown
N	Power N	Input	blue
B1	Probe 1 (Room)	Input	red/white
B2	Probe 2 (Evap)	Input	red/white
B3	Probe 3 (Discharge)	Input	red/white
B4	Probe 4 (Aux)	Input	red/white
DI1	Digital Input 1	Input	gray
DI2	Digital Input 2	Input	gray
NO1	Relay 1 (Comp)	Output	black
NO2	Relay 2 (Def)	Output	orange
NO3	Relay 3 (Fan)	Output	green
NO4	Relay 4 (Aux)	Output	yellow
A	RS485 A (+)	Comm	blue
B	RS485 B (-)	Comm	yellow

Important: Always disconnect power before wiring. Verify terminal numbers with the actual controller label before connecting.

Code	Parameter	Range	Default	Description
St	Setpoint	-50 to 150	5 °C	Main setpoint
S2	Night Setpoint	-50 to 150	3 °C	Energy saving setpoint
rd	Differential	0.1 to 20	2 °C	Control differential
c4	Comp ON Delay	0 to 255	0 min	Startup delay
c5	Min Comp OFF	0 to 255	3 min	Minimum off
d0	Defrost Type	0-3	1	Defrost method
d1	Defrost End	0 to 50	8 °C	Termination temp
d2	Max Defrost	1 to 255	30 min	Maximum duration
d3	Defrost Interval	0 to 48	8 hr	Time between
Ad	Modbus Address	1 to 247	1	Device address