M847A Draft Damper Operator
EXTENDED BRACKET
MODEL
APPLICATION
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.
SHORT BRACKET
MODEL
CHAIN
LINKAGE
ARM
LINKAGE
INSTALLATION INSTRUCTIONS
SPECIFICATIONS
Models: with 965 mm (38") length of chain, or with actua-
tor arm.
Electrical Rating: 24 V 8VA 60Hz
Thermostat Heater Setting: — .32 amp.
Nominal Angular Rotation of Wheel: 45 degrees.
Torque (at actuator wheel): 212 mN•m* (30 inch ounces).
Motor Timing: 20 seconds maximum in the powered
direction, 20 seconds maximum on spring closing.
Ambient Temperature Rating: 5 to 50° C (+40 to 125° F).
Finish: zinc plated
Direction of Rotation of Actuator Wheel: when ener-
gized, this wheel rotates in the clockwise direction when
facing the wheel.
Mounting Means: bracket provided may be secured to
any flat surface within the temperature limitations
stated above.
Mounting Position: any position except when using chain
linkage where actuator wheel should be vertical (see
Fig. 3).
Dimensions: See Figs. 1 & 2.
* mN•m — MILLI NEWTON METRE
Fig. 1. Extended Bracket Model. Dimensions in mm
(inches) are nominal.
95C-10110EF-03