Leprecon VX Dimmer - Manual (Page 6)

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The VX dimmer system uses a modular control card for each 12 channel dimmer. This control
card incorporates over voltage detection and shutdown to protect the dimmer electronics and
lamp loads from destruction.
The VX control card features three green LED's for power indication. These indicators show that
each phase is connected and within normal limits. If all three LED's are not lighted, power is not
applied, is out of range, or a fault is present in the VX system.
The internal protection takes effect at 140 volts AC. Voltages of this level or above will light the
red Over voltage LED on the power supply drawer front panel, and disable all dimmer control.
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.
3.5. Temp LED and Fan Control
Each channel of the VX 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 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.
3.6. Connection to Terminal Power Inlet
The most common power input connector for the Leprecon VX 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 VX
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