Exploding capacitors are the most common and worst failures in conventional systems, and can be caused by ageing, moisture in the capacitor and high harmonics in an installation.

Sparking in a luminaire can cause damaged wiring or continuous ignition pulses when lamps are failing. Recommended are digitally controlled igniters to switch off defective lamps.

Because of the high currents, under-tightened screw connectors can cause excessive heat to damage the ballast.