
Selec CH403C Cooling Controller – 3 Digit LED Display
Selec CH403C Cooling Controller – NTC Sensor Based, Defrost Management, 36×72 mm
Compact refrigeration controller with NTC input, ON-OFF control, defrost management, adjustable hysteresis, °C/°F selection, alarm output (model-dependent), and universal 90–270V AC/DC supply. Ideal for chillers, display coolers, deep freezers, and cold rooms.
The Selec CH403C is a compact ON-OFF cooling controller designed for refrigeration, chillers, deep freezers, and commercial cooling equipment. It features a 3-digit LED display, NTC sensor input, adjustable hysteresis, defrost management, °C/°F selection, door mode, reset delay, and optional alarm or SSR outputs based on model. The controller supports universal AC/DC supply for easy integration.
Key Features
3-digit LED white display with capacitive touch keys
NTC sensor-based temperature control (–40 to +90°C)
ON-OFF control action with adjustable hysteresis (0.1–99.9°C)
Defrost management with programmable defrost time and defrost frequency
Heat & Cool mode selection
Door open mode
Reset time delay (0–99 min)
Display offset adjustment
°C/°F selectable
Main relay outputs:
10A (standard)
20A (LUG type – CH403C-2-NTC)
Alarm output:
SSR 12V (CH403C-1-NTC V2)
5A relay (CH403C-3-NTC)
Universal supply: 90–270V AC/DC
IP65 front protection (when panel mounted)
Technical Specifications
Display Specifications
| Parameter | Value |
|---|---|
| Display Type | 3-digit, 7-segment white LED |
| Status Indication | Set-point lock, Defrost, Relay ON |
Input Specifications
| Parameter | Value |
|---|---|
| Sensor Type | NTC Thermistor |
| Temperature Range | –40 to +90°C |
| Nominal Resistance | 10 kΩ @ 25°C |
| Indication Accuracy | ±1% of full scale |
Functional Specifications
| Parameter | Value |
|---|---|
| Control Action | ON-OFF |
| Set Point Range | –19.9 to +20.0°C |
| Resolution | 0 / 0.1°C |
| Hysteresis | 0.1 to 99.9°C |
| Defrost Time | 0–99 min |
| Defrost Frequency | 0–99 hr/min/sec |
| Reset Time Delay | 0–99 min |
| Modes | Heat/Cool |
| Door Mode | Yes |
Output Specifications
| Model (variant) | Output |
|---|---|
| CH403C-1-NTC | Relay 10A |
| CH403C-1-NTC V2 | Relay 10A + SSR Alarm (12V) |
| CH403C-2-NTC | Relay 20A (LUG type) |
| CH403C-3-NTC | Relay 10A + Alarm Relay 5A |
Auxiliary Supply & Environment
| Parameter | Value |
|---|---|
| Supply Voltage | 90–270V AC/DC |
| Power Consumption | 3 VA max |
| Operating Temperature | 0 to 50°C |
| Storage Temperature | –20 to 75°C |
| Humidity | 95% RH non-condensing |
| Protection | IP65 front (panel mounted) |
Mechanical Specifications
| Parameter | Value |
|---|---|
| Panel Size | 36×72 mm |
| Dimensions | 76 × 34.5 × 65.3 mm |
| Panel Cutout | 29 × 71 mm |
| Weight | 150 g |
Applications
Commercial refrigerators
Deep freezers
Visi coolers
Chillers
Blast freezers
Display counters
HVAC cooling cycles
What’s in the Box?
Selec CH403C controller
NTC Temperature Probe (TSP04)—Range –40 to +100°C, 10 kΩ @ 25°C
Mounting clamps
User manual
Warranty card
FAQs
Q1. Is the temperature probe included?
Yes—the CH403C is supplied with an NTC TSP04 probe.
Q2. What is the maximum relay capacity?
10A for standard models, 20A (LUG type) for CH403C-2-NTC.
Q3. Does it support defrost mode?
Yes—defrost duration and frequency are fully programmable.
Q4. Can the controller show temperature in °F?
Yes—°C/°F selection is available.
Q5. Does it have an alarm output?
Yes—depending on the model, either SSR output or a 5A relay is available.
Q6. What is the power supply range?
Universal 90–270V AC/DC.