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Electronic Theatre Controls Inc

AC Voltage on 0-10v Lines

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Issue

0-10v Analog dimming uses DC voltage. ETC 0-10v (Fluorescent) Option Cards and 0-10v Analog Gateways should be used with isolated 0-10v drivers to reduce the risk of damage. This means little or no AC voltage should be present on the 0-10v lines. While some small amounts of AC voltage can be handled, more than a few volts can cause damage to original option card or gateway electronics. While damage to control electronics has been mitigated by circuit redesigns, AC voltage on control lines can still present a personal safety hazard and must always be taken seriously.

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Damage caused to ETC product by mains voltage leaks on 0-10v control lines is not covered by warranty!

Checking for AC Voltage

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Do not work inside of a live rack! When testing, the ETC rack / enclosure must be closed and 0-10v wiring must be removed from the enclosure.

In order to check your lines for AC voltage, you must un-land and remove the 0-10v wires from the ETC 0-10v card or gateway and test them outside of the ETC equipment / enclosure. A True RMS Multimeter is required for accurate readings.

Test for AC voltage between positive and negative wires as well as between each conductor and ground. Typically positive wires are Violet and negative are Gray, although effective 1/1/2022 Pink is the standard color for negative 0-10v conductors.

Testing procedure:

  1. Begin with the control circuit for the 0-10v driver de-energized.
  2. Verify that the 0-10v conductors are disconnected from ETC equipment and made safe - capped off with a wire nut or similar.
  3. Energize the control circuit for the 0-10v driver.
  4. Use a True-RMS Multimeter to measure AC and DC voltage on the 0-10v control wires from pole to pole and each pole to ground. It would be prefered to have a meter that had separate setting for AC & DC, Auto only meters are difficult to read in this situation. If any measurement exceeds 20VAC additional voltage isolation is required or there may be a problem driver on the line. Do not connect 0-10v wiring to the ETC control card until this condition is resolved.
  5. If you believe that these high readings are ghost voltage, you can re-test with a lowZ meter and see if the voltage drops away. If they do then that was ghost voltage. For more information on ghost voltage see the ETC White Paper: Understanding 0-10V LED Drivers.
  6. Observe that all fixtures are full bright when control wires are open and that when shorted all fixtures on the circuit go to their minimum level. If some or all fixtures do not dim, there is a problem with drivers or field wiring. The ETC controller cannot cause or resolve this kind of problem.
  7. If all of the above tests pass, de-energize the driver circuit and connect the 0-10v wires to the ETC control card.

Here is a handy Excel file for recording Voltage: 0-10 Measurements.xlsx / PDF version: 0-10 Measurements.pdf

Solution

MKI 0-10v Cards (Shipped Prior to Spring 2024)

Up to 15VAC from conductor to conductor or conductor to ground is acceptable, though less than ideal. 20VAC and higher will cause damage to electronics, and must be filtered.

  • ETC was using the EATON model number RFI-010v-1 LC, part number 12512441 (ETC part# SGE1508), but it was discontinued by EATON in Nov of 2021.
    eaton filter.jpg
  • A possible equivalent is the nLight nFLT2.
  • ETC has a 2-channel unit that 7187A1191 FLT-LV 2-ch 0-10v filter designed for simple j-box installation.
  • 7187A1191 top view.jpg             7187A1191 Side View.jpg
  • There are two sets of wires tie wrapped separately. Each set is for a channel consisting of:
    • Purple (+10v) and Gray (COM) that goes to the Fixture Drivers.
    • Purple/White stripe (+10v) and Gray/White stripe (COM) that goes to the control device (ETC equipment).
  • Ground wire must be attached to earth ground or the unit will not properly protect the circuit.
  • For larger 0-10v installations with AC voltage issues, there are larger wall mount kits as well. The enclosure is the same size as a Foundry Mini Panel, approximately 16"x14"x4.9".
    Model Part number Part Description
    FLT-LV 7187A1191 2 Channel 0-10V Filter Box, Knockout Mounted
    FLT8-LV 7187A1192 8 Channel 0-10V Filter Box, Wall Mounted
    FLT16-LV 7187A1193 16 Channel 0-10V Filter Box, Wall Mounted
    FLT24-LV 7187A1194 24 Channel 0-10V Filter Box, Wall Mounted

MKII 0-10v Cards (Shipped Spring 2024 and Later)

MKII 0-10v cards have had a significant PCB redesign. Each 0-10v output is isolated from the rest of the card as well as isolated from ground. This means that while AC voltage may be present on the 0-10v circuit, there is no path to ground on the output circuitry, so even high levels of AC voltage should not damage the card.

However, unlike a 0-10v circuit that has had its AC voltage filtered, a 0-10v circuit with high voltage present connected to a MKII card still presents a safety hazard. Metering the 0-10v lines before connecting them to the panel is still a requirement.