Selec HC404 3-Digit Single Display Humidity Controller
Selec HC404 Digital Humidity Controller – 36×72 mm, RH Sensor, 10A Relay Output, IP65
Compact ON/OFF humidity controller with built-in RH sensor input, 0–100% RH range, 10A relay output, auxiliary alarm relay, capacitive touch keypad, and IP65 front protection for industrial and HVAC applications.
The Selec HC404 is a compact humidity controller designed for HVAC, industrial drying, storage rooms, laboratories, and environmental chambers. It features a 0–100% RH control range, reliable ON/OFF control, a built-in RH sensor input, a 10A main relay output, an auxiliary alarm relay, an IP65 front panel, and capacitive touch keys for long-life operation.
KEY FEATURES
3-digit, 7-segment white LED display
Capacitive touch keypad
RH sensor input (5V supply)
0–100% RH control range
10A at 250VAC main relay output
5A at 250VAC alarm relay output
Humidification/Dehumidification modes
Display offset adjustment (−19.9 to 19.9)
Reset time delay: 0–99 min
IP65 front protection
Compact 36×72 mm housing
Wide supply: 90–270 VAC/DC
IDM applicable (Selec Industrial Design)
TECHNICAL SPECIFICATIONS
1. Display Specifications
| Parameter | Value |
|---|---|
| Display | 3-digit, 7-segment white LED |
| Indications | Setpoint lock, Relay ON, Alarm |
2. Input Specifications
| Parameter | Value |
|---|---|
| Sensor Type | RH Sensor (3-wire: +5V, GND, Signal) |
| Input Range | 0–100% RH |
| Sensor Cable Length | 1 meter (extendable up to 3 m) |
| Accuracy | ±1% of full scale |
| Resolution | 1% / 0.1% |
3. Control & Output Specifications
| Parameter | Value |
|---|---|
| Control Action | ON–OFF (Humidity) |
| Main Relay Output | 10A @ 250VAC |
| Alarm Relay Output | 5A @ 250VAC |
| Humidification/Dehumidification | Supported |
| FTC | 0.2 to 10 sec |
4. Functional Settings
| Setting | Range |
|---|---|
| Display Offset | −19.9 to +19.9 |
| Reset Time Delay | 0–99 minutes |
| Alarms | High alarm (HA/PV), Low alarm (LA/PV) |
5. Power Supply Specifications
| Parameter | Value |
|---|---|
| Supply Voltage | 90–270V AC/DC |
| Power Consumption | 3 VA max @ 230V AC |
6. Environmental Specifications
| Parameter | Value |
|---|---|
| Operating Temp | 0°C to 50°C |
| Storage Temp | −20°C to 75°C |
| Humidity | 95% RH (non-condensing) |
| Compliance | IEC 61326-1, CISPR-11, IEC 61000-4 (various levels) |
7. Mechanical Specifications
| Parameter | Value |
|---|---|
| Mounting | Panel mount |
| Dimensions | 76 × 36.5 × 65.3 mm |
| Weight | 93 g |
| Sensor Dimensions | 52 × 28.8 × 18 mm |
APPLICATIONS
HVAC dehumidifiers & humidifiers
Industrial drying and curing systems
Storage rooms & warehouses
Mushroom & agricultural chambers
Clean rooms & environmental chambers
Textile/hygroscopic material processing
WHAT’S IN THE BOX
HC404 humidity controller
1× RH sensor with 1-meter cable
Panel mounting hardware
User guide
FAQS
Q1. What is the power supply range?
HC404 operates from 90–270V AC/DC.
Q2. Does it include an RH sensor?
Yes—a 3-wire RH sensor is included with a 1-meter cable.
Q3. What is the relay rating?
Main relay: 10A, Alarm relay: 5A.
Q4. Can the controller perform both humidification & dehumidification?
Yes, selectable.
Q5. Is the front panel waterproof?
Yes—IP65 protected.
Q6. How far can I extend the RH sensor cable?
Up to 3 meters, after which accuracy may vary by 1% per meter.