The M847A is a two position, low voltage spring return
damper operator designed for use with 24 VAC room thermostats, or other low
voltage controllers, to operate the draft damper on solid fuel furnaces or
boilers, or other similar light duty applications. The damper operator is
equipped with a mounting bracket and is intended for wall, duct, direct furnace
or boiler mounting to control a draft damper through a direct actuator arm, or a
chain linkage arrangement, depending on the model selected.