Leprecon VX Series Dimmer - Manual (Page 6)

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Input from a controller or from the channel Test switches will be ignored, and no voltage will be
output from any dimmer channels. As soon as the applied voltage is reduced to a safe level, the
Over voltage LED will be quenched, and the dimmer will begin to operate normally.
3.4. Temp LED and Fan Control
Each channel of the VX / MX rack system has its own temperature sensor. If a problem occurs
that causes a channel to overheat, the entire dimmer shuts down until a normal temperature is
reached. This overtemp shutdown is indicated by lighting the red Temp LED.
VX / MX racks are cooled by temperature controlled fans mounted in each 12 channel section.
The same temperature sensor that is used for thermal shutoff also determines the fan speed. This
arrangement allows for the lowest possible noise level from the cooling fans while still providing
proper cooling for the hottest module. Noticeable airflow and fan noise will only occur when the
dimmer is loaded and channels are turned on long enough for the internal temperature to start to
rise.
3.5. Connection to Terminal Power Inlet
The most common power input connector for the Leprecon VX or MX 2400 dimmer is the
Terminal Power inlet. This option provides an insulated terminal strip with 7 screw connections for
3 phase power. The block is labeled to identify the three power phases ( X Y Z ), neutral
connections and a safety ground. Because of the large neutral current that can exist in phase
control systems, two screw terminals are supplied for neutral connection.
It remains the responsibility of the user to determine the correct cable type to properly connect
dimmer racks, and the need for overcurrent protection in the power supplied to the dimmer
system.
For more information, see the appendix of this manual.
4. Control Input
4.1. DMX 512
All Leprecon VX and MX dimmers are compatible with DMX 512. To connect the dimmer to a
DMX controller, simply use a standard DMX cable and plug the two devices together. A parallel
wired female connector is supplied to allow output to additional dimmers or other devices.
4.1.1. DMX Indicators and controls
The VX / MX Control card located at the top of the pack contains the electronics needed to
decode the digital DMX signal, and translate that information into signals to control 12 dimmer
channels. On the front panel are the indicators and controls for DMX inputs.
The green LED labeled "signal" is lighted whenever a DMX signal is being received. This indicates
that the controller, cable and DMX input to the VX / MX dimmer system are functional.
The three thumbwheel switches labeled "Start Address" are used to select the board channels
that the dimmer will respond to. For instance, a switch setting of 001 will assign dimmer channel 1