Airfield Lighting Systems single switching unit for switching individual lighting fittings.
Widely used for stop-bar control.
The ALS SSU is available in either Fail-On or Fail-Off versions.
The ALS SSUs enables the suppression of any LED or incandescent lamp from 1W to 100W that uses a 6.6A supply down to 1A.
The SSU is also available in the form of a combined switching transformer with both items cast in the same encapsulated unit.