What is 0-10 vdc signal and what is it used for?
0-10vdc is an analog control signal used to control damper and valve actuators, VFD Control, temperature, humidity and pressure sensors, and temperature reset. It is a very common control signal used in the HVAC industry that is straightforward, easy to troubleshoot, and widely accepted throughout the world.
| How is it measured ?
Using a voltmeter capable of checking DC voltage.
Step 1. Identify the wires signal (+) and the negative/common (-)
Step 2. Set your meter to DC Volts
Step 3. Place the positive lead from the meter to the signal output terminal (Example: White wire in the picture below) and the negative lead on the ground/common terminal (Example: Black wire in the picture below).
Step 4: Notice the output voltage is 5vdc which is the midpoint of a 0-10vdc signal. (Example if this was a damper actuator the damper would be open halfway or 50%).
| How does this relate to Smart Nodes?
The Smart Node has two 0-10vdc analog inputs and two 0-10vdc corresponding outputs. The output voltage can be varied to test devices connected to the outputs. (Example Damper or Valve Actuator)
| How to perform output test ?
- Selected outputs can be tested using the following steps. Press the right arrow button on the 75F logo and scroll to the outputs menu screen.
- From the outputs menu on the Smart Node press the down button to select the desired analog output.
- Press the right button and note the default value of the output. Press the up and down buttons to change the range, voltage, or action of the output. (Example 0v -> 7v)
- After testing return value of the output to its default setting, press the left button and then the up button to return to the menu.
| Points to Remember
When checking a 0-10vdc signal the meter leads must be connected in parallel with the signal wires not in series like 4-20ma signal.
The positive lead connects to the source of the 0-10vdc signal.
The negative lead connects to the ground/common.