York D3EG 036 frcetoonebetensioningatthe, 2Never, thedeflection, straightedgefrom, until, Defl

035-14832-003-A-0204

PILOT CHECKOUT

The pilot flame should envelope 3/8 inches of the end of the flame sensor. Refer to Figure 12. To adjust pilot flame, (1) remove pilot adjustment cover screw, (2) adjust the screw for the proper pilot flame, (3) be sure to replace cover screw after adjustment to prevent possible gas leakage.

FIG. 12 - PROPER FLAME ADJUSTMENT

Put the system into operation and observe through complete cycle to be sure all controls function properly.

BURNER INSTRUCTIONS

To check or change burners, pilot or orifices, CLOSE MAIN MANUAL SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE UNIT.

1.Remove the two screws holding either end of the manifold to the burner supports.

2.Open the union fitting in the gas supply line just upstream of the unit gas valve and downstream from the main manual shut-off valve.

3.Remove the gas piping patch plate.

4.Disconnect wiring to the gas valve and spark ignitor. Remove the manifold-burner gas valve assembly by lifting up and pulling back.

Burners are now accessible for service.

Reverse the above procedure to replace the assembly. Make sure that burners are level and seat at the rear of the heat exchanger.

BURNER AIR SHUTTER ADJUSTMENT

Adjust burner shutters so that a distinct, sharp, blue flame is obtained. Refer to Figure 13.

FIG. 13 - TYPICAL FLAME APPEARANCE

SUPPLY AIR AIR BLOWER AND TEMPERATURE RISE ADJUSTMENTS

The speed of the supply air blower will depend on the required CFM, the unit accessories and the static resistances of both the supply and the return air duct systems. With this information, the speed for the supply air blower can be determined from the blower performance and accessory static resistance data in Table 5 through 8.

Knowing the required blower RPM and the blower motor HP, the speed setting for the supply air motor can be determined.

The setting (turns open) for the optional belt-drive supply air motor pulley can be determined from Table 13.

TABLE 13 - BELT-DRIVE SUPPLY AIR

MOTOR PULLEY ADJUSTMENT

TURNS	BLOWER DRIVE RANGE (RPM)
OPEN*	3 TON	4 TON	5 TON
5	780	790	850
4	842	856	924
3	904	922	998
2	966	988	1072
1	1028	1054	1246
0	1090	1120	1220

*Pulley can be adjusted in half-turn increments.

OPTIONAL BELT-DRIVE BLOWER

All units with belt-drive blowers have single speed motors. The
				CAUTION
variable pitch pulley on the blower motor can be adjusted to
Procedure foradjustingblttension:
obtain the desired supply air CFM. Refer to Table 9 for blower
1Loosennut(D)fromthemotormount.						should be
mot and drive data. The tension on the belts
2Never			nuts(C)fromeachotherwhilelooseningnut(D).
4Donotloosen				thefournuts(topandbottom)(A);unlessadditional
adjust		as shown in Figu 14.			frcetoonebetensioningatthe
5U.Adjusttancebelttensioncheckertoapplya
3	di	thetsionbyturningbolt(B).
		isrequired;immediatelyre-tight theseboltsifloosened.
	thedeflection			fromnormalposition,perpendicularuse	straightedgefrom
	midpointofthespanasshown.Thedeflctionforceshouldbeappiedl
	until	specificdeflectiondistanceof4mm(5/32")isobtained.Todetermine
	sheavetosheavedistanceas referenceline.Therecommendeddeflectionforce
	isasfollows:			ENGTH
				DEFL
				SPAN
				FORCE

deflectionsTnsion.Checknewbeltstheatbeltthetemaxnsionshould.(Ade)atfectiasontbefrotwtic(C)*eenmeserecdo*uringmmendNEVER(D)theand(B)LOOSENfirstfor24thehoursbeltof operati6.Aftertoloosenadjusting,.forceAnynutsrevalues-(C)tenionre-.tighten.ingnut(D)againstfall themotortheminmount. takingmax.carenot

FIG. 14 - BELT ADJUSTMENT

Start the supply air blower motor. Adjust the resistances in both the supply and the return air duct systems to balance the air distribution throughout the conditioned space. The job specifications may require that this balancing be done by someone other than the equipment installer.

To check the supply air CFM after the initial balancing has been completed:

1.Remove the (two) ￿￿￿ " dot plugs from the holes located on the filter access panel side of the unit.

2.Insert at least 8" of 1/4 inch tubing into each of these holes for sufficient penetration into the air flow on both sides of

the evaporator coil.

Unitary Products Group 15