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Electronic Theatre Controls Inc

What is the overvoltage threshold for a DRd?


The processor in my DRd rack is giving me an overvoltage error, and I don't know how to determine if the voltage is actually too high.

Description/Explanation of Issue

Generally speaking, a true overvoltage error will be generated when the incoming voltage on one or more phases of power is ~10% higher than the rated voltage. In a 120V rack, this would correspond to ~132V; in a 277V rack, this would correspond to ~304V. The overvoltage is detected by the dimming engine mounted in the top of the rack, which then triggers the error in the processor.


  1. Perform a full rack powercycle by shutting off the power input to the rack, waiting 30 seconds, and powering back up to see if the error clears.
  2. If not, have a certified electrician meter the voltage of the incoming power on each phase, and between phases.
  3. If the voltage is within acceptable bounds, power down the rack, remove the dimming engine, and make sure all wire harnesses are fully seated, and undamaged.
  4. Failing all of the above, please contact ETC Technical Services to continue troubleshooting.
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