Characterisation of CSS supplied emergency lighting equipment

By M Granziero et al

Scope of this paper is to report results of an experimental research aiming to characterize emergency lighting equipment behavior during switch on transients with static CSS supply.

Emergency lighting equipment inrush current peak values and waveforms are typically very dispersed depending on technology and manufacturers and can create problems when sizing or operating CSS equipments. High peak values can lead to CSS electronic protection tripping.

Emergency lighting centralized systems are nowadays becoming a growing issue due to higher safety level requirements in addition to higher lighting power needed. Considering the lack of available reliable data on lighting equipment behavior, inrush current issue is currently approached by CSS over sizing. The research aims to fill this gap providing statistical data obtained with a proper scientific approach. Given the importance of CSS cost, the availability of such data will allow system designers to optimize CSS sizing, reducing both operative (maintenance and losses) and installation costs.

The key factor for an optimal CSS sizing is the knowledge of the behavior of lighting equipments during switch on phase: the cool start phase is typically considered the most critical condition. Measurements described in this paper have been carried out on different types of lamps typically used in emergency installations around Europe mains supplied. Further investigations have been done with sample lamps CSS supplied.

Network supply conditions have been chosen in order to evaluate the parameters describing phenomenon in terms of duration, maximum peak value and current rms value during turn on transients.

CSS supply conditions have been chosen in order to evaluate lighting equipment behavior with current limitation and non sinusoidal waveform.