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Mounting Actuators
CAUTION
Maximum damper rotation is 70°. Maximum shaft torque is
205 inches/pound. Greater rotation or torque can cause
equipment damage.
The installing contractor is responsible for the mounting of
all field-installed actuators. No provisions are made for the
location of these actuators due to the number of options and
arrangements available and the variety of specific applications.
Typically, actuators are mounted inside the cabinet. Provide
proper support for the actuator to avoid excessive stress in the
cabinet, linkage, or damper shafts.
Fresh air and return air dampers can be linked together for
each half and driven from the same actuator if the dampers
are the same size. If the dampers are different sizes, they must
be driven by separate actuators and controlled appropriately.
Exhaust dampers are always driven by a separate actuators.
A typical rotary electric actuator can handle up to 40 sq. ft. of
damper. For pneumatic actuators, allow 5 in-lb per square foot
of damper area.
Face and/or Bypass Damper Torque
Requirements
The dampers are not linked and require multiple actuators -
four for the face dampers and two for the bypass dampers.
A damper shaft extension is provided. Normally, the shaft
extension is located on the drive side of the unit, but it can be
moved to the other side.
Face and bypass dampers have a torque requirement of 10
in-lbs per square foot of damper face area.
Isolation Dampers for Multiple Fans
Optional isolation dampers can be provided on multiple fans
to prevent backflow through a fan that is turned off for service.
These isolation dampers are not intended to be used to control
flow through the fan. The isolation damper for a fan that is
going to be started must be positioned in the full open position
before the fan is started. Do not start a fan with the damper
located at the inlet with the damper fully or partially closed.
This can cause airflow, vibration, and sound problems that can
lead to failure.
Isolation dampers can be provided with actuators that are
mounted in the airstream. Actuator sizing for the isolation
dampers should be based on 9 in-lb per square foot of damper.
IM 915-13 • VISION - EXTENDED SIZES
Piping and Coils
When designing and installing piping:
• Follow applicable piping design, sizing, and installation
information in ASHRAE handbooks.
• Observe all local codes and industry standards.
• Do not apply undue stress at the connection to coil
headers; always use a backup pipe wrench.
• Support pipework independently of the coils.
Water Cooling Coils
• Water supply, water return, drain, and vent connections
extend through the end panel of the coil section. All
connections are labeled on the end panel.
• Water supply and water return connections are typically
male NPT iron pipe.
• When installing couplings, do not apply undue stress
to the connection extending through unit panel. Use a
backup pipe wrench to avoid breaking the weld between
coil connection and header.
• Follow recommendations of the control manufacturer
regarding types, sizing, and installation of controls.
Direct Expansion Coils
• The coil distributor and suction connection extend through
the end panel of the coil section.
• Check nozzle in distributor for proper tonnage.
• When a field supplied thermostatic expansion valve is
used, it is located outside the unit and connected directly
to the distributor. Do not apply heat to the body of the
expansion valve.
• The thermostatic expansion valve must be of the external
equalizer tube type. Connect the 1/4-inch diameter
external equalizer tube provided on the coil to connection
on expansion valve.
• Use care when piping the system to see that all joints
are tight and all lines are dry and free of foreign
material. For typical refrigerant piping, see condensing
unit product manual.
16
Installation Guidelines
www.DaikinApplied.com
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