INSTALLATION
INSTRUCTION
MOTORIZED OUTDOOR AIR
DAMPER ACCESSORY
(MODEL 2MD04700224)
Supersedes: Nothing
FOR SINGLE PACKAGE EQUIPMENT AIR CONDITIONERS &
HEAT PUMPS
7-1/2 THRU 12-1/2 TONS
GENERAL
The instruction provides all the necessary information to properly field-install the motorized outdoor air damper accessory on
the above indicated equipment.
The accessory is motor operated with spring return dampers
allowing entry of outdoor air into the conditioned space every
time the indoor fan motor is energized in the heating and
cooling mode. It also includes a hood and filters (for field
assembly) to prevent rain an debris from entering the system.
Damper wiring connection may be referenced on the two labels
furnished with this accessory and should be applied o the unit
wiring label located on the inside of the control box access
panel. Both labels should be applied over the respective areas
currently shown as “economizer control”.
A relief air damper for barometric air balance is provided with
each basic unit and is mounted on the return air duct cover or
in the return air duck work. Refer to the basic unit installation
instruction for additional information.
INSTALLATION
Install the air damper assembly and hood per the following
procedure: General unit orientation and rainhood assembly are
shown in Figure 1.
1. Remove the filter section access panel and the outdoor air
opening cover from the unit. Discard cover only - keeping
the eight sealing screws as extras for possible use later.
NOTE: When operating the unit with side air discharge applications, the side duct covers may be discarded bottom supply and return duct covers must remain
secured in place. When operating the unit with down
air discharge applications, the bottom duct covers may
be discarded - side supply and return air duct covers
must remain secured in place.
2. Before installing the damper assembly into the unit, the
divider partition must first be secured in place. Position the
triangular shaped partition in the area between the outdoor
and return air duct openings. Place the 3 holed flange
facing the duct panel with the insulated side of the partition
facing the unit filter access opening.
FIG. 1 - ECONOMIZER / MOTORIZED DAMPER RAIN HOOD
530.18-N3.4V (987)
035-07582
Remove the three screws (A) between the outdoor and
return air duct openings on the unit back panel, align the
holes in the partition flange with the holes in the back panel
and secure with the 3 screws that were just removed. See
Figures 1 and 2.
NOTE: Compress the insulation on the inside of the base for
proper positioning of the partition. Exercise care when
installing so the the foil face of the insulation will not be
damaged.
3. Insert the damper assembly into the unit filter section,
sliding along the “Y” type flange of the filter rack at the
bottom and the “Y” type flange of the support baffle at the
top. See Figure 2. Slide it all the way in until the damper is
against the blower partition. Align the 3 holes in the flange
on the underside of the damper assembly with the 3 holes
in the divider partition and secure with the three screws
provided.
CAUTION: When sliding the damper assembly into position,
check to insure that electrical leads (on some gas
units) are repositioned so they will not be compressed between the damper frome and the insulated blower partition. Be careful not to damage the
foil face of the insulation.
5. An electrical control harness is secured above the top filter
rack for damper operation. Uncoil this harness and plug it
into the MATE-N-LOCK connector on the damper assembly.
CAUTION: Remove and discard the jumper plug from the
harness receptacle before connection is made to
the damper assembly.
Position the control harness so that it will not interfere with
the operation of the damper motor, the damper linkage or
the damper blades.
6. Adjust the tamper linkage as shown in Figure 3. The end of
one linkage rod (loose for shipping purposes only) must be
inserted into its respective bushing. Adjust rod so that it is
flush with left surface of the bushing and tighten.
ASSEMBLY (OPTION)
- To the hood cover flange (only on unit sizes 10
tons and over). No gasketing required on units of
ten tons or less.
b) Attach two filter guide angles to the inside of each side
plate using 3 screws for each angle. Note the hole
locations on the angles for proper positioning when
attaching them on the side plates. Tighten screws.
c) Attach two side plates to the center filter support using
4 screws on each side. Do not tighten screws.
d) Attach the bottom filter support between the side plates
using 2 screws on each side. Do not tighten screws.
e) Attach hood cover to the side plates using 3 screws on
each side. Do not tighten screws.
f) Set hood assembly on a flat surface to insure all components are plumb, then tighten all screws.
9. Attach the hood assembly over the outside air opening on
the unit duct panel as follows:
FIG. 2 - DAMPER ASSEMBLY INSTALLATION
7. Adjust the damper opening by manually moving the
thumbwheel on the damper motor (See Figure 3) to the
desired setting. The outdoor air dampers begin to open as
the thumbwheel is moved toward MAX position and begin
to close when moved toward the MIN position.
For full open outdoor air dampers, disconnect wire 54B at
terminal “X” on damper actuator and connect to terminal
“D”. Refer to the labels furnished with this accessory.
8. Assemble the rainhood shown in Figure 1 per the following
procedures:
a) Apply gasketing to all hood components as follows:
- To the top outside surface and to the flange (toward
unit) of each side plate. Extend gasketing 1/2" beyond the top and bottom of the flange to insure adequate sealing.
On unit sizes under 10 tons the flange of the hood cover
must be inserted in under the unit to cover flange. One
screw in the unit cover flange must be removed and one
screw (at the right side corner of the unit cover flange)
needs only to be loosened to allow the notched flange of
the hood cover to slide into place. Replace and tighten 2
screws.
On unit sizes 10 tons and over, secure the hood flange to
the duct panel with 3 screws. Use holes in the hood cover
flange as a template and drill 3 holes, 9/64" dia. (#26 drill)
in the duct panel.
On all units, attach the hood side plate flanges to the duct
panel by drilling 6 holes, 9/64" dia. (#26 drill) for each side
plate at the dimples provided in the duct panel. Secure hood
into position using 6 gaskets screws in each side plate.
10. Insert two 1" filters into the center of the hood, coming to
rest in the center filter support at the back of the hood. Press
the filters against the filter guide angles on the side plates.
Use 1 screw (B) on each side of the hood to hold the filter
into position. Insert two 1" filters into the bottom filter
supporter per the same procedure as the center filters.
- To the edge and flange (in one continuous length)
on each side of the center filter support.
NOTE: Install filters so that “Air Flow” arrows point upward,
toward the unit.
- To the top flange of the bottom filter support (on the
side facing the unit).
11. Replace the filter section access panel.
FIG. 3 - LINKAGE ROD ADJUSTMENT
Subject to change without notice. Printed in U.S.A
Copyright  by Unitary Products Group 1996. All rights reserved.
Unitary
Products
Group
745 Industrial
Parkway
West
Elyria
Ohio
44035
.11
Codes: SBY, F, L
530.18-N3.4V