As you are well aware, an electrical licence is necessary to work on any ‘prescribed electrical work’ in New Zealand. This essentially refers to anything above 50V, which has caused some confusion around 100V line speaker systems.
Worksafe NZ was approached to clarify its position on these speaker circuits. It replied:
“These speaker circuits are rated to be producing full power when 100VRMS is present; however, audio (background music, paging, fire evacuation etc) has a very high peak-to-average ratio and thus the voltage present is normally well below 30VRMS, except for very short duration transients.
“As speaker wiring is not work on an electrical installation, it is not prescribed electrical work.”