Selec HTC405 3 Digit Single Display Humidity + Temperature Controller
Selec HTC405 Humidity + Temperature Controller – 36×72 mm, Dual 7A Relays, RH + RTD Input, PID/ON–OFF Control
Dual-function humidity and temperature controller with RH sensor input, RTD PT100 temperature input, 7A relay outputs, PID/Auto-Tune control for temperature, ON/OFF control for humidity, 3-digit LED display, and 90–270V AC/DC supply.
The Selec HTC405 is an integrated humidity and temperature controller designed for industrial HVAC, storage, drying, and environmental control applications. It provides ON–OFF humidity control and ON–OFF or PID temperature control with auto-tuning, using a 3-digit LED display, dual 7A relays, capacitive touch keys, and an RH sensor included with the unit.
KEY FEATURES
Humidity and temperature in one controller
3-digit white LED display
RH sensor input (HS-A-100 included)
RTD PT100 input for temperature
ON–OFF humidity control
ON–OFF / PID / Auto-Tune / Self-Tune temperature control
Dual relay outputs, each rated 7A at 250VAC / 30VDC
Resolution: 0.1%/1% RH and 0.1°C for RTD
Temperature units: °C / °F selectable
IP65 front protection
Wide supply: 90–270V AC/DC
Compact 36 × 72 mm panel size
TECHNICAL SPECIFICATIONS
Display Specifications
| Parameter | Value |
|---|---|
| Display | 3-digit, 7-segment white LED |
| LED Indication | OUT1: RH Control ON; OUT2: RTD Control ON |
Input Specifications
| Parameter | Value |
|---|---|
| Humidity Sensor Input | RH (HS-A-100) |
| Temperature Input | RTD PT100 (3-wire) |
| Input Range | 0–100% RH ; RTD −50°C to +400°C |
| Input Filter (FTC) | 0.2 to 10 sec |
| Resolution | 0.1 / 1 %RH ; 0.1°C |
| Sampling Time | 250 ms |
Output Specifications
| Output | Type | Rating |
|---|---|---|
| RH Control Output | Relay SPDT | 7A at 250VAC / 30VDC |
| Temperature Control Output | Relay SPDT or SSR selectable | 7A at 250VAC / 30VDC |
Functional Specifications
| Parameter | Range/Details |
|---|---|
| Humidity Control | ON–OFF only |
| Temperature Control | ON–OFF / PID / Auto-Tune / Self-Tune |
| Proportional Band (P) | 1.0 – 400.0°C |
| Integral Time (I) | 0–99.9 min |
| Derivative Time (D) | 0–999 sec |
| Cycle Time | 0.1–99.9 sec |
| Hysteresis Width | 0.1–99.9°C |
| Manual Reset | −19.9 to +19.9°C |
Power Supply Specifications
| Parameter | Value |
|---|---|
| Supply Voltage | 90–270V AC/DC (50/60 Hz) |
| Power Consumption | 4 VA max at 230 VAC |
Environmental Specifications
| Parameter | Value |
|---|---|
| Operating Temp | 0°C to 50°C |
| Storage Temp | −20°C to 75°C |
| Humidity | 95% RH (non-condensing) |
Mechanical Specifications
| Parameter | Value |
|---|---|
| Panel Size | 36 × 72 mm |
| Depth | 65.3 mm |
| Weight | 93 g |
| Sensor Weight | 33 g |
| Sensor Cable Length | 1 m (extendable to 3 m; +1% error/meter) |
Terminal Connections
RH Sensor:
RD = +5V, BL = GND, GR = SignalRTD PT100: terminals 3–4–5
Relays:
OUT1 (RH): NO1 / COM1 / NC1
OUT2 (TEMP): NO2 / COM2 / NC2Supply: L, N
Humidity Sensor Performance
Typical tolerance: ±2 %RH
Maximum tolerance: ±6% RH
The ratiometric voltage vs RH curve shown
APPLICATIONS
HVAC humidifiers & dehumidifiers
Temperature and humidity chambers
Industrial drying & curing
Storage rooms & warehouses
Greenhouses & mushroom farms
Textile & paper production
Environmental monitoring systems
WHAT’S IN THE BOX
HTC405 main controller
RH Sensor (HS-A-100) with 1 m cable
Mounting clamp
User manual
FAQS
Q1. Is the RH sensor included?
Yes—the HS-A-100 sensor with a 1 m cable is included.
Q2. What relay ratings are available?
Both outputs are 7A SPDT at 250VAC/30VDC.
Q3. Does HTC405 support PID control?
Yes—for the temperature (RTD) channel. Humidity uses ON–OFF.
Q4. What is the supply voltage?
90–270V AC/DC.
Q5. Can the sensor cable be extended?
Yes—up to 3 meters (accuracy varies +1% per extra meter).
Q6. What is the panel size?
36×72 mm front bezel.