Over the past year, reports of flickering lights have been increasing. Most complaints concern the administration building’s conference rooms. A few years ago, the incandescent lamps were replaced with screw-in LED replacements. The replacements worked fine, whether dimmed or at full illumination.
In the plant, a similar problem is happening in some areas, and none of the LED lamps are on dimmers. Furthermore, LED conversion in the plant has been almost entirely a complete LED assembly rather than a screw-in replacement.
A recording DMM hung (in turn) in several administration building branch circuits didn’t show much variation in line voltage. In the plant, this method showed some big, brief swings; these were attributed to the “across the line” starting of a couple of large motors.
What might be causing the flicker?
First, check whether the dimmers are LED-compatible.
Voltage variations are only one power concern. Those drivers need clean power, so look at the waveform using a power analyzer or a meter with scope functions. You may find the power quality in the branch circuits, while suitable for other lighting technologies, is not good enough for your LED lighting systems. You may need to contact the manufacturer to determine if this is the case. Make a point of determining what has changed between the time the LED lighting worked fine and now. For example, what new equipment was installed?
Age is another issue. When were these lights installed? Although they have a design lifespan, it can be accelerated by events such as transients, exposure to excess humidity, or even temperature fluctuations (especially those that cause condensation).
