MINIMUM POSITION SETTING
CHECKOUT
The ZDs have a minimum
position setting that allows the
damper to remain open to a pre-
set position instead of closing off
fully. This minimum position
provides for a small amount of air
to be by-passed through the
damper to lessen the need for a
separate by-pass damper and
provide continual air circulation.
To set the minimum position, set when there is no power to the
damper and it is in the open position. Loosen the long minimum
position set screw and move to a desired setting shown on the
minimum position label and re-tighten. When the damper is
powered closed the minimum position screw will stop the damper
at the position set.
NOTE: This label and screw does not indicate the position of
the damper. It is only used to set the minimum position.
The ZD damper is a very simple damper to checkout. The two (2)
wire spring return design simply requires a check for voltage at the
motor when the damper is to be CLOSED. There must be 24 Volts
AC, at the motor when the controller or switch provides power to
the motor. When the is no power to the motor the damper will
spring return back to its normally open position.
REPLACEMENT MOTOR
To replace the motor, loosen the locking set screw on the inside collar
ring of the motor that holds the motor to the damper blade shaft,
remove the moved and replace with the new motor. And re- tighten
the set screw.
6 Aspen Drive -- Randolph, New Jersey 07869-1103
Telephone 1-201-794-8004 FAX 1-201-794-1359
www.zonefirst.com info@zonefirst.com
© 2017 ZONEFIRST® Form 2043-0710
