Introduction
Temperature controllers are used to regulate temperature of a system by controlling heating/cooling equipment. The XH-WH300x series are on/off type temperature controllers that are simple to use and affordable. In this article, we’ll be having a look at the XH-W3002 temperature controller and how to use it to control heating and cooling.
XH-W3002 Review
XH series is a set of low-cost, accurate temperature controllers that need minimum external components. They are also known as digital thermostats. Digital thermostats, unlike analog ones, can control temperature very precisely.
The XH-W3002 is a direct alternative to the XH-W3001 temperature controller. It is an upgraded version of the W3001 controller with a few additional features.
W300x series temperature controllers are on/off type, meaning that they regulate temperature by turning a heater or a refrigeration compressor/fan depending on the temperature measurement. The device reads the current temperature using a temperature sensor (NTC thermistor) and determines when to turn on/off the load based on the configuration.
Similar to the W3001, W3002 temperature controller is also available in a few configuration options based on input power and load ratings. The three models are similar: there is a 12VDC, 24VDC and a 220VAC model.
The 12VDC and 24VDC require external DC power sources to power the device. The 220V variant has the power supply built-in to reduce external component count. All the devices can output the supply voltage from its load output wires. The typical maximum load is about 10A.
With the pre-attached 10 kilo Ohm NTC thermistor, WH3002 can also measure system temperatures from -50°C to 100°C. The accuracy of the measurement is about +/-0.1°C when correctly calibrated with the offset values.
As mentioned earlier, the W3002 is the upgraded version of W3001 with an additional ‘set’ button with a delayed start option. Unlike its predecessor, the W3002 has a menu that has 3 options.
XH-W3002 User Manual
XH series temperature controllers are manufactured by a multitude of manufacturers. HexaControls is one of them. The user manual for the XH-W3002 temperature controller can be found in this link. Let’s have a look at some of the important information about the temperature controller:
XH-W3002 Technical Specifications
Following are the hardware specifications of the controller:
| Feature | Description |
| Temperature Range | -50°C to 110°C |
| Operating Voltage | 12/24VDC or 220VAC |
| Operating Mode(s) | Heating or Cooling |
| Output Mode and Power | 120W, direct 2-point output |
| Output Current | 10A (max) |
| Input Type | 10K NTC Thermistor, encased in 1m waterproof probe |
| Temperature Control Accuracy | 0.2°C |
| Temperature Sensing Accuracy | 0.1°C |
| Mounting | DIN rail or wall-mount using screws |
| Housing Material | Plastic, IP22 rated |
| Dimensions | 60x45x31mm |
Similar to W3001, this sensor is also available in three variants based on the supply/operating voltage as follows:
| Model | Power Input |
| XH-W3002-12 | 12VDC |
| XH-W3002-24 | 24VDC |
| XH-W3002-230 | 230VAC |
The 220VAC variant has an internal power supply to power up the digital control circuitry. The output control circuit is capable of handling up to 10A. However, it is recommended to use the output to drive a load such as a high power relay or a contactor to drive a large load. This increases the lifespan of the controller.
In addition to the buttons and the digital display, there is an indicator LED at the top right corner to indicate if the output is on or off.
The rear of the controller has markings to indicate the type of the controller. The appropriate box will be marked based on the operating voltage and the power output of the XH-W3002 temperature controller.
Also, the XH-W3002 comes with a 4-option menu that has following functions:
| Menu Option | Description |
| P0 | Start Temperature |
| P1 | Stop Temperature |
| P2 | Calibration (+/-0.1 degrees Celsius increments) |
| P3 | Delay start (increments in minutes) |
The controller can auto-select if it’s being used in a heating or cooling application.
If the start temperature is larger than stop temperature, then the device is in cooling mode. The output will turn on when the temperature rises above start temperature. Similarly, the output will turn off when the temperature reaches the stop temperature once the system cools down.
XH-W3001 vs XH-W3002
W3001 and W3002 are very similar in terms of form factor, the functionality and even the measurement ranges. The main difference between the two controllers is the extra button on the XH-W3002 controller. This button is used to navigate through the software menu supported by the device.
As mentioned in the previous section, the XH-W3002 has four settings which can be accessed through the ‘set’ button: P0, P1, P2 and P3.
XH-W3002 Thermostat Wiring and Programming
Use the following wiring diagrams to connect the XH-W3002 temperature controller to a system.
If the unit is a XH-W3002-230 type which works with 230VAC, use the following wiring:
If the unit is XH-W3002-12 or XH-W3002-24, use the following wiring scheme to connect the device.
Configure and Program the XH-W3002 Thermostat
The configuration of the controller is done using the set button. Press it once to enter the menu. The display will start P0. The up/down arrow keys can be used to cycle between P0/P1/P2 and P3. Press the set button once to enter the selected setting.
To set the device to heating mode, the start temperature must be lower than stop temperature. To set the start temperature, press the set button until the display shows P0 and adjust the start temperature value using up/down arrow keys. The setting is automatically saved after 3 seconds. Similarly, select the P1 setting using the set button and use up/down keys to adjust the stop temperature.
In heating mode, the output turns on when the temperature goes below the start temperature and turns off when the temperature goes above the stop temperature value.
To set the device to cooling mode, the start temperature must be higher than stop temperature. To set the start temperature, press the set button until the display shows P0 and adjust the start temperature value using up/down arrow keys. The setting is automatically saved after 3 seconds. Similarly, select the P1 setting using the set button and use up/down keys to adjust the stop temperature.
In cooling mode, the output turns on when the temperature goes above the start temperature and turns off when the temperature goes below the stop temperature value.
The P3 mode is the calibration mode. This allows the user to set the temperature offset in positive or negative increments of 0.1 degree celsius to compensate for temperature reading errors.
P4 is the delayed start feature supported by XH-W3002 temperature controller. The user can specify the minutes from 0 up to 10 to delay the output from turning on when required. The setting supports increments of 1 minute.
Conclusion
The XH-W3002 temperature controller is an affordable, simple, on/off type temperature controller that is a direct replacement to XH-W3001. This device can act both as a cooling and a heating control unit depending on the configuration. It supports configurable, delayed output switching.
