Carrier 38AH024-034 - Manual (Page 20)

TOP OF FAN ORIFICE FILL HOLE IN FAN HUB
PROP LOCATION “A” in. (mm)
60 Hz
38AH024-034
3.5 (89)
50 Hz
38AH024-034
4.3 (109)
Fig. 14 — Location of Prop on Motor Shaft
from Outside of Orifice Ring
Table 4 — Pressure Switch Settings, psig (kPa)
HIGH PRESSURE LOW PRESSURE
Cutout Cut-in Cutout Cut-in
426 ± 7 320 ± 20 27 ± 3 44 ± 5
(2937 ± 48) (2206 ± 138) 186 ± 21) (303 ± 34)
PRESSURE
DIFFERENTIAL
ADJUSTMENT
SCREW
CONTROL
SET POINT
ADJUSTMENT
-NUT
POWER HEAD
VALVE BODY
BYPASS
PISTON RING
BYPASS PISTON
DIFFERENTIAL SCREW
SEALING CAP
(CAP MUST BE REPLACED
TO PREVENT REFRIGERANT LEAKAGE)
Fig. 15 — Capacity Control Valve
Winter Start Control — Purchase accessory Carrier
part no. 38AE900021 for winter start control.
Head Pressure Control — Control allows system to
operate at full capacity under low ambient temperature
conditions.
FAN CYCLING — These 38AH units have standard pro­
vision for fully automatic intermediate-season head pres­
sure control through condenser fan cycling. Fan no. 2 is
cycled by an outdoor-air thermostat which responds to out­
door ambient temperature. The thermostat is loeated in the
lower divider panel between the compressor compartment
and condenser section. Through a hole in the panel, the
sensing element is exposed to air entering the no. 1 fan
compartment. Fan no. 1 is non-cycling. Table 5 shows the
operating settings of the air temperature switch.
Table 5 — Fan Cycling Controls
CONTROL BY SWITCH OPENS SWITCH CLOSES
Temp — F (C) 60 ± 3 (15 6 ± 1.7) 70 ± 3 (21.1 ± 1.7)
NOTE: See Fig. 6 for fan arrangement.
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