POWERdrive 50W DESIGN GUIDE
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July 30, 2020
Page 10/19
Grounding
Depending on the type of DMX-compliant cable that is used, the DMX shield conductor may be separate from the cable
shield/drain wire. The DMX Shield should only connect to earth ground at the DMX controller. Inside the fixture, the DMX
Shield should only connect to the DMX Shield terminal on the driver. Termination of the DMX cable inside the luminaire
must ensure that the DMX Shield does not come into electrical contact with the fixture body.
DMX Input isolation
The DMX control interface is electrically isolated from the Class 2 LED outputs and mains input. This improves the
robustness of the POWERdrive LED driver against surge events and accidental mis-wiring.
4. Driver protections
The POWERdrive 50W driver has several protection mechanisms to comply with certification standards (e.g. UL Class 2
LED outputs) and to prevent damage to the driver during operation. These protection mechanisms include:
Thermal protection
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When the internal LED driver temperature exceeds a factory preset limit, the output
current on all LED outputs is gracefully scaled back until the LED driver temperature drops below this limit. If the
internal LED driver temperature continues to increase, despite a decrease in output current, the LED driver
eventually shuts down when a second temperature threshold is reached. Once the temperature drops below the
threshold, the driver will restart.
Open protection
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All LED outputs are turned off whenever the LED driver detects an open circuit on any one of
the LED outputs. The LED driver will automatically attempt a restart every 400ms after an open circuit is
detected.
Ceiling
Pendant
Fixture
DMX +
DMX -
DMX SHIELD
Single cable down stem
Shared DMX
shield/drain conductor
Junction Box
DMX IN
DMX OUT
Figure 6: This example shows how a cable with two twisted conductor pairs can be used to bring a DMX signal to a
pendant luminaire, while still minimizing the length of the T tap.
