OPTIONAL ECONOMIZER RAIN HOOD
The following procedure should be used when assembling an economizer rain hood onto a unit.Refer to Figure 4.The outdoor and return air dampers, damper actuator, the linkage and all the controls are factory mounted as part of the economizer option.
All of the hood components, including the filters, the gasketing and the hardware for assembling are located above the top filter racks within the filter section. The outdoor air sensor is in the bag of parts located at the bottom of the return air section.
1.With filter section access panel removed, take out hood components, filters and sensor described above. Remove and discard outdoor air opening cover on back unit (Upper right hand corner).
2.Remove the 1/2" knockout (A) in the units rear panel (located to the right side of the outdoor air opening). Insert the two loose wires from inside the unit, into the 1/2" bushing provided. Insert wires and bushing into knockout. Snap bushing into place.
3.Mount the outdoor air sensor to the rear panel, just below the knockout described in Step 2. Secure with two
NOTE: Sensor must be positioned so that the sensing ports are at the top (louvers pointing downward) and terminal connections to the right.
4.Connect the two wires, indicated in Step 2, to the sensor as follows:
•Wire #73 to terminal (+)
•Wire #74 to terminal (S)
5.Assemble the LH and RH side plates to the top cover (2 screws each side) to form the hood. Apply gasketing to the flange surface on each side plate. Extend gasketing 1/4" beyond top and bottom of each flange to insure adequate corner sealing. Secure this assembly to the unit back panel (upper right hand corner). First, remove screw (C) on unit top cover. Then slip flange of hood cover in under flange of unit top cover, replace screw (C), engaging hole (E) in hood
flange and tighten. Attach the two side plates to the unit panel by using two
6.Position fillpiece at bottom of hood, between the two side plates but do not secure at this time. (Slotted openings MUST be downward for drainage). After fillpiece is properly positioned, note where contact is made with the unit panel. Remove fillpiece and apply gasket material to this area to provide a seal. Reposition fillpiece and secure with 2 screws.
7.Install the two filters into the hood assembly, sliding down along retainers on side plates, into fillpiece at bottom of hood.
NOTE: Install filters so that "Air Flow" arrows point toward the unit.
8.Install filter cover over the end of the hood with one screw (center of hood), securing filters into position.
CAUTION: When proceeding with steps 9 and 10, extreme care must be exercised while turning both the set point and minimum position adjusting screws to prevent twisting them off.
9.The enthalpy set point for the dampers may now be set by selecting the desired
10.To check that the damper blades move smoothly without binding, carefully turn the minimum position adjusting screw fully clockwise and then energize and
11.Replace the filter section access panel.
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| OUTDOOR AIR |
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| OPENING COVER | C |
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| HOOD |
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| FILTER | COVER |
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| D |
| OUTDOOR AIR | |
| COVER |
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| E | D | SENSOR | |
GASKETED |
| |||
| D | A |
| |
FLANGE |
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| GASKET | |
| B | D | ||
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L. H. SIDE
PLATE
| GASKETED | FILTER SECTION |
| ACCESS PANEL | |
| FLANGE | |
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| |
FILTERS | R. H. | SIDE DUCT |
| SIDE | APPLICATION SHOWN |
| PLATE |
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FILLPIECE |
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FIG. 4 - ECONOMIZER RAIN HOOD ASSEMBLY (OPTION) |
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6 | Unitary Products Group |
