"were installed to" is correct and usable in written English.
Example sentence: Surveillance cameras were installed to help keep the streets safe.
New stairs were installed to the loft.
Eventually wooden borders were installed to stem the lawn's removal.
Lipstick cameras were installed to provide the live video.
Searchlights were installed to illuminate the death strip at night.
But players always felt the cameras were installed to monitor them.
Bio-digesters were installed to generate biogas by decomposition of the organic matter.
Humidifiers and freestanding air-conditioners were installed to prevent deterioration, the trustees reported to the family.
Large wooden beams were installed to support the old building until construction of the station house was completed.
Fifteen hundred columns were installed to support the street-level deck and the buildings that would rise on it.
BuzzFeed News originally reported that these "OccupEye" sensors were installed "to monitor whether journalists are at their desks".
Speed bumps and a roundabout were installed to slow traffic.
