York B3CH 048 and 060 Optional Economizer Rain Hood, Economizer Rain Hood Assembly Option

035-12984-001-A-0204

heater accessory installation instruction for the heater electrical data.

The minimum air flow limitations across these heaters are listed in Table 2.

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 13mm (12in.) 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

13mm (12in.) 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 self- drilling screws at dimples (B) provided in the panel.

NOTE: Sensor must be positioned so that the sensing ports are at the top (louvers pointing downward) and termi- nal 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

flange14surface on each side plate. Extend gasketing 6mm ( in.) beyond top and bottom of each flange to insure ade- quate 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 self-drilling screws for each side plate at dimples (D) provided in the panel.

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 set-point from graph in Figure 5. For a single enthalpy economizer, carefully turn the set-point ad- justing screw to the “A”, “B”, “C” or “D” setting correspond- ing to the lettered curve. For a dual enthalpy economizer, carefully turn the set-point adjusting screw fully clockwise past the “D” setting.

10.To check that the damper blades move smoothly without binding, carefully turn the minimum position adjusting

		OUTDOOR AIR
		OPENING COVER	C
		HOOD
	FILTER	COVER
		D		OUTDOOR AIR
	COVER
		E	D	SENSOR
GASKETED
		D	A
FLANGE				GASKET
		B	D

L. H. SIDE

PLATE

	GASKETED	FILTER SECTION
		ACCESS PANEL
	FLANGE
FILTERS	R. H.	SIDE DUCT
	SIDE	APPLICATION SHOWN
	PLATE
FILLPIECE
FIG. 4 - ECONOMIZER RAIN HOOD ASSEMBLY (OPTION)

6 Unitary Products Group