EN54-16 and EN54-24 Certificated Voice Evacuation System Class D amplifier for voice alarm system, 120W to 500W per channel. ... two fans for automatic start up when inner temperature reaches 55°C. Complete protection system includes power on, overheat, short ... circuit and overload.Features* Class-D power amplifier for voice evacuation system* 120W, 240W, 350W & ...