The Elta 149-TC310 is a 3‑phase transformer speed controller providing reliable 5‑step fan speed adjustment for loads up to 10 amps. Housed in an IP40-rated enclosure, it is built for environments with ambient temperatures up to 40°C. This controller is ideal where low noise operation is essential, as it avoids the magnetic hum typically found in stepless controls. Note: illuminated on/off switch and MCB protection features apply only to single-phase models.