Analog 0/1-10V Topology
0-10 V topology is a common control topology that can be found all across the lighting industry.
It was originally developed for control of ?uorescent ballasts, but in the growing market of LEDs, it has become one of common control topologies. While there are some standard details to how 0-10 V works as a topology, there are many details that can a?ect the quality of the end solution.
0-10 V topology is often looked at as an open topology and that 0-10 V products work together without any issues
0-10 V mA Rating
Directly related to the previous notes on sink vs. source, every 0-10 V device has a rating for how much current (in mA) that it sources or sinks. In addition to stating that the ballast shall source the current, the IECR 60929 standard dictates a minimum ballast source current of 10 μA and a maximum of 2 mA. Not all ballasts/drivers follow this standard (2 mA maximum), but it can be used as an approximation if no information can be determined about the ballast/driver being used. Knowing the sinking/sourcing capabilities of the control and the ballast/driver are necessary to determine the maximum number of ballasts/drivers that can be controlled by a single control circuit. Te maximum number of ballasts/drivers can be found by taking the sink capability of the control and dividing by the source current of each ballast/driver. Te mA rating and the relay rating are the two limiting factors for how many ballasts/drivers can be used with a control. With LED lamps, it is very common for the mA rating to be the limiting factor.
How many fixtures can I put on a 0-10 V control circuit?
There are three limiting factors that come into play when determining how many ballasts/drivers you can have 0-10 V circuit.
1. Steady state current
2. Inrush current
3. Te mA sink/source on the 0-10 V circuit
Te application needs to be within the wattage rating of the 0-10 V control, within the 0-10 V current sink/source capability, and able to handle the inrush of the loads to be connected. If the capabilities of the control (found in Table 1) and the specs of the ballast/driver are known, the maximum number of ballasts/drivers on a circuit can be determined.
How far can I run a low-voltage 0-10 V circuit?
There are a number of variables that affect how long a 0-10V circuit can be run. Some of these variables include: the number of ballasts/drivers, the source rating of each ballast/driver, the gauge of the wire, any noise that might be experienced by the wire run, and what voltage drop will allow the control to maintain a minimum light level. If the 0-10V circuit is going to be run as Class 2 wiring (assuming no significant noise), a standard voltage drop equation can be calculated to find out the voltage drop for a given distance Due to the number of variables that exist, Lutron cannot provide a number that can be used in all applications. The IECR 60929 Annex E standard states that at 1V, the ballast/diver should be at a minimum light level, Since the ballast/driver is the source, that means the voltage will drop along the Wire and be lower at the control. For example: if the control is capable of pulling the voltage down to 0 7.V and the voltage drop along the wire is 0.3V, the voltage at the ballast/driver will be 1V. As a general rule, keeping the voltage drop to 03.V or lower is a good practice.
The total voltage drop for a wire run can be calculated using the following equation:
Vd= R x d x n x I
"Vd" is the voltage drop, "R" is the resistance of the wire per foot, "d' is the distance of the wire run, 'n is the number of ballasts/drivers, and "I" is the current (A) sourced by each ballast/driver. If the equation is re-arranged to solve for distance it becomes: d= Vd/ ( R x n x I)