Carrier 48TJD008-014 Ð Enthalpy Settings for, PARABLADE Economizer, Ð Panels Reinstalled on Unit

CONTROL	CONTROL POINT
	F (C) (APPROX)
CURVE
	AT 50% RH

A73 [23]

B70 [21]

C67 [19]

D63 [17]

RH Ð Relative Humidity

Fig. 30 Ð Enthalpy Settings for

PARABLADE Economizer

Fig. 31 Ð Panels Reinstalled on Unit

Fig. 32 Ð Outdoor-Air Hood Installed on Unit

Fig. 33 Ð Filter Installed on Outdoor-Air Hood

Step 9 Ð Adjust Evaporator-Fan Speed Ð Ad- just evaporator-fan speed to meet jobsite conditions.

Table 3 shows fan rpm at motor pulley settings, Table 4 shows motor efficiencies and Table 5 gives accessory static pressure drops. Table 6 shows motor performance. Refer to Tables 7-14 to determine fan speed settings. Fan motor pul- leys are factory set for speed shown in Table 1.

To change fan speed:

1.Shut off unit power supply.

2.Loosen belt by loosening fan motor mounting plate nuts (see Fig. 34 and 35).

3.Loosen movable pulley ¯ange setscrew (see Fig. 36).

4.Screw movable ¯ange toward ®xed ¯ange to increase speed and away from ®xed ¯ange to decrease speed. Increasing fan speed increases load on motor. Do not exceed maxi- mum speed speci®ed in Table 1.

5.Set movable ¯ange at nearest keyway of pulley hub and tighten setscrew (see Table 1 for speed change for each full turn of pulley ¯ange).

To align fan and motor pulleys:

1.Loosen fan pulley setscrews.

2.Slide fan pulley along fan shaft.

3.Make angular alignment by loosening motor from mount- ing plate.

To adjust belt tension (see Fig. 34 and 35):

1.Loosen fan motor mounting plate nuts.

2.Units 008,009 Ð Slide motor mounting plate away from fan scroll for proper belt tension (1¤2-in. de¯ection with one ®nger) and tighten mounting nuts (see Fig. 34).

Units 012,014 Ð Slide motor mounting plate downward to tighten belt tension. Secure motor mounting plate nuts. See Fig. 35.

3.Adjust bolt and nut on mounting plate to secure motor in ®xed position.

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