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W2401 20A -50C ~ 100C Digital Temperature Controller Installation and Operating Instructions
Where to Buy the W2401 Temperature Controller:
The W2401 is a low cost yet highly functional panel-mountable thermostat temperature controller. It controls power to most types of electrical devices based on the temperature sensed by the included high-accuracy NTC remote temperature sensor.
The W2401 Controller is available in 2 Options:
W2401-N (Relay Contacts)
With the W2401-N the cooler, heater or fan is connected to a power supply through the relay contacts S0 and S1, and the temperature on/off setpoints are programmed into the W2401-N using the onboard Set, Increase and Decrease buttons and displays. The relay contacts are then open and closed, acting as a power switch for the cooler/heater, based on the temperature measured by the NTC temperature sensor (included with the module) and the setpoints programmed into the W2401 controller. The 12V DC support power is only used to power the W2401-N circuitry. The power for the load (cooler, heater or fan) is connected to the load through the relay, as shown in the diagram below and can be any voltage up to 250VAC at up to 20 Amps at 14V DC, and up to 10 Amps at 250V AC.
W2401-O (12V Active Output)
The W2401-O provides an active 12VDC output and can power the cooler, heater or fan at up to 20A, 240W. The W2401-O only provides 12V DC power for the load. If you need a voltage other than 12V DC to power your device, use the W2401-N.
To assist in identifying which model you are working with, the W2401-N (Relay Contacts) has a blue printed circuit board, and the output screw terminals are labeled S1 and S2. The W2401-O (12V Active Output) has a green printed circuit board and the output screw terminals are labeled O+ and O-.
W2401-N and W2401-O Specifications
- Temperature Control Range: -58°F to 212°F (-50°C to 100°C).
The temperature is only displayed in Centigrade, the controller cannot be switched to Fahrenheit. - Resolution at -9.9 to 99.9: 0.1 C
- Resolution at all other temperatures: 1 C
- Error: ±1%
- Refresh Rate: 0.5 Seconds
- Input Support Power (DC): 9V minimum to 12V maximum
- Measuring Input: NTC 3950 (10K 0.5%)
- Waterproof Sensor: 100cm (~3 Ft) cable
- LED1 (Blue):
- Real-time temperature when operating
- Start temperature when programming (flashing)
- LED2 (Red): Stop temperature
- Output:
- W2401-N: 1 Channel Relay Output, Capacity: 20A at 14V DC, 10A at 250V AC
- W2401-O: 12VDC (same as input voltage) at up to 20A (240 Watts)
- Dimensions
- 47.6 × 28.6 × 33.2 mm / 1.9 × 1.12 × 1.3 inches (LxWxD)
- Panel Cutout Dimensions: 45 × 26.1 mm / 1.8 × 1.02 inches
W2401 Interconnection (Both Models)
- Plug the NTC thermistor (temperature probe) into the connector on the back of the module.
- Connect an appropriate 12V DC power supply or battery to the screw terminals marked IN+ and IN-, V+ to IN+ and V- to IN-.
If using the W2401-O (12V Active Output) model, connect the load (heater, cooler or fan) to the screw terminals marked O+ and O-. The load must operate on 12V DC, and must draw less than 20 Amps of current.
If using the W2401-N (Relay Outputs), the power for the load is connected in series with the load through the relay screw terminals labeled S1 and S2, as shown in the diagram above. The power supply can be any voltage up to 250VAC at up to 20 Amps at 14V DC, and up to 10 Amps at 250V AC
W2401 Programming and Operation
The W2401’s operation is controlled by the Start and Stop temperatures programmed using the Set, Up, and Down buttons. To enter the programming mode:
- Double-press the “S” button, and LED1 will flash
- Set the Start temperature using the Up and Down buttons
- Tap the “S” button to save the setting, and LED2 will flash
- Set the Stop temperature using the Up and Down buttons
- Tap the “S” button to save the settings and return to operating mode. LED1 will now display the current real-time temperature, and LED2 will display the Stop temperature that you programmed above
- When the output of the device is on (the relay is energized), the red LED labeled “OUT” will illuminate
Heating Mode
When the Start setpoint (LED1) is less than the Stop setpoint (LED2), the controller is in heating mode. For example, set Start (LED1) to 20 degrees, and Stop (LED2) to 30 degrees. When the probe temperature (displayed on LED1 during operation) drops to 20 degrees, the controller’s Output will turn on (the relay will energize), the OUT LED will illuminate, and the output will stay on (heating) until the temperature increases to 30 degrees, at which time the relay will turn off. The output will stay off until the temperature cools to 20 degrees, at which time this cycle will repeat.
Cooling Mode
When the Start setpoint (LED1) is greater than the Stop setpoint (LED2), the controller is in cooling mode. For example, set Start (LED1) to 30 degrees, and Stop (LED2) to 20 degrees. When the probe temperature (displayed on LED1 during operation) increases to 30 degrees, the controller’s Output will turn on (the relay will energize), the OUT LED will illuminate, and the output will stay on (cooling) until the temperature decreases to 20 degrees, at which time the relay will turn off. The output will stay off until the temperature warms to 30 degrees, at which time this cycle will repeat.
Programmable Options
The W2401 temperature controller has two programmable options, P0 and P1. To enter the programming mode, press and hold the “S” button for 6 seconds and P0 will be displayed. Tap the S button to advance to P1.
P0: Temperature Calibration
When in P0 programming mode, LED1 displays the real-time temperature, and LED2 displays the temperature that you want it calibrated to. Set the temperature using the up and down buttons until the desired temperature is displayed in LED2, then tap the Set button to save it and advance to P1.
P1: Delayed Start
The default is 0. The delay start time can be set from 0 to 10 minutes using the up and down arrows. When set to any value other than 0, the start will be delayed by the programmed number of minutes after the triggering event.
Factory Reset
To reset the W2401 to its factory reset values, with power off, press and hold the “S” button. Apply power, and release the “S” button after the LED illuminates.
Hysteresis
How much change in temperature must occur before the relay changes state, set by the Start and Stop setpoints, is called hysteresis. A small hysteresis can lead to undesired rapid cycling of the equipment. For example, if the Start setpoint is 20 degrees and the Stop setpoint is 21 degrees, the controller output will turn on and off every time the temperature changes by 1 degree. Setting the hysteresis to a higher value helps stop the thermostat from continually triggering when the temperature drifts around the trip temperature.
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