170
3. See Fig. 53 and adjust fan height using a straight edge laid
across the fan deck.
4. Tighten setscrew to 12.5 to 13.75 ft-lb and replace rubber
hubcap to prevent hub from rusting to the motor shaft. Fill
hub recess with Permagum if hub has no rubber hubcap.
5. Replace fan guard.
Fig. 52 —
Pulley Alignment
Fig. 53 —
Condenser-Fan Adjustment
CONDENSER FAN ADJUSTMENT (PLASTIC FANS)
Each fan is supported by a formed wire mount bolted to a fan
deck and covered with a wire guard. The exposed end of the
fan motor shaft is protected from weather by grease. If the fan
motor must be removed for service or replacement, be sure to
regrease fan shaft and reinstall fan cover, retaining clips, and
fan guard. For proper performance, the fans should be posi
-
tioned as shown in Fig. 54. Tighten setscrews to 14
1 ft-lb
(18
1.3 N-m).
Check for proper rotation of the fan(s) once reinstalled (coun
-
terclockwise viewed from above). If necessary to reverse,
switch leads at contactor(s) in control box.
Fig. 54 —
Condenser Fan Position (Plastic Fan)
AIR PRESSURE TRANSDUCER FIELD ADJUSTMENT
All transducers have been factory calibrated and should not re
-
quire field adjustment. If field adjustment is necessary, follow
the instructions below. To re-calibrate a transducer:
1. Shut the unit power off.
2. Take the wiring and pressure tubing off the transducer.
Take the transducer out of the unit.
3. Connect a 24-vdc power supply to transducer terminals
EXC(+) and COM(–). See Fig. 55.
4. Using a digital multimeter measure the current between
terminals EXC(+) and OUT.
5. With both pressure ports open to atmosphere adjust the
Zero (Z) screw potentiometer on the transducer and read
the multimeter until the desired current output at 0 in. wg
pressure is obtained (see Fig. 55).
6. Reinstall the transducer in the unit.
7. Restore power to the unit.
Fig. 55 —
Transducer Details
TRANSDUCER
PART
NUMBER
INPUT
RANGE
(in. wg)
OUTPUT
RANGE
OUTPUT
AT 0 IN. WG
USAGE
HK05ZG019
0-5
4-20 mA
4 mA
Air Foil
Fan Cfm
HK05ZG020
0-1
4-20 mA
4 mA
Return
Fan Cfm
HK05ZG022
–0.25-0.25 4-20 mA
12 mA
Building
Pressure
PLASTIC FAN
PROPELLER
CLEARANCE OF 0.25 INCHES
(6.4 MM) FOR STANDARD
CONDENSER FANS
FAN DECK
SURFACE
FAN ORIFICE
PRE
SS
URE POR
T
S
LOW
HIGH
S
Z
COM OUT EXC
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...