9
Blower Speed
The blower speed is preset at the factory for an external
static pressure of 0.2-0.3 in-Wg. For optimum system
performance and comfort, it may be necessary to change
the factory set speed. Refer to Blower Performance Data
(Tables 5 - 10, pages 24 - 29) for the allowable operating
range and adjustments.
WARNING:
To avoid personal injury or property damage,
make certain that the motor leads cannot
come into contact with any uninsulated metal
components of the unit.
To change the blower speed:
1. Disconnect all electrical power to the unit and remove
the blower access panel.
2. Loosen the motor tension bars to allow removal of the
blower belt from the motor sheave.
3. Loosen top set screw on motor sheave and turn
clockwise to close (increases blower speed), or
counterclockwise to open (decreases blower speed).
4. Replace belt on pulleys and position motor mounting
plate to correct position for proper belt tension.
5. Tighten tension bar bolts.
Check all factory wiring per the unit wiring diagram and
inspect the factory wiring connections to be sure none
loosened during shipping or installation.
STARTUP & ADJUSTMENTS
Pre-Start Check List
•
Verify that the unit is level to allow proper condensate
drainage.
•
Verify that there is free airflow to and from the outdoor
coil and that all clearance requirements are met.
•
Verify that the ductwork is sealed to prevent air leakage.
•
Verify that the line voltage power leads are securely
connected and the unit is properly grounded.
• Verify that low voltage wires are securely connected
to correct leads in the low voltage area of the control
box.
•
Verify that all exterior panels are replaced and securely
fastened.
•
Verify that the outdoor fan turns freely.
•
Verify that the power supply branch circuit overcurrent
protection is sized properly.
•
Verify that the thermostat is wired correctly. The
thermostat function switch should be set to
Off
and
the thermostat fan switch should be set to
Auto
.
Start-Up Procedure
WARNING:
The unit is equipped with crankcase heaters.
Allow 24 hours prior to continuing the start up
procedures to allow for heating of the refrigerant
compressor crankcase. Failure to comply may
result in damage and could cause premature
failure of the system. This warning should be
followed at initial start up and any time the
power has been removed for 12 hours or longer.
• Check unit for return air filters and condensate trap.
• Check all electrical wiring for loose connections and
tighten as required.
• Close all electrical disconnects to energize the system.
Air Circulation
Leave the thermostat system switch set to
Off
and set
the thermostat fan switch to
On
. The blower motor should
run continuously. Check for air delivery at the register(s).
Ensure that there are no obstructions at the registers or
in the ductwork. Set thermostat fan switch to
Auto
, the
blower will shut down immediately.
NOTE:
If blower is
turning opposite of arrow direction, shut off main power to
the unit and switch any two field wires at the disconnect.
DO NOT
alter unit wiring.
System Cooling
1. Set the thermostat system switch to
Cool
and the
thermostat fan switch to
Auto
. Lower the thermostat
temperature switch below room temperature and
observe that the blower, both compressors and fan(s)
energize. Check that air cooler than room temperature is
being discharged at the register. Ensure unit refrigerant
pressures are in order. Blower should be turning in
direction indicated by arrow.
NOTE:
If refrigerant
pressures are abnormal and blower is rotating in the
opposite direction of the arrow, shut off main power to
the unit and switch any two field wires at the disconnect.
Ensure proper rotation of both compressors.
DO NOT
alter unit wiring. Listen for any unusual noises. Locate
the source and correct as needed.
2. After allowing the unit to run for several minutes, set
the temperature selector above room temperature,
verify that the fan, blower, and compressors cycle off
with the thermostat.
System Heating - Field Installed Electric Heat
This packaged air conditioner is designed to allow an
optional electric heat kit to be field installed as required
by the building’s particular heating load. The options
available for each unit are shown in the heater kit installation
instructions or unit technical service literature. Install the
heater kits as directed by the instruction sheet that comes
as part of the heater kit. Follow all cautions and warnings
as directed. Use only NORDYNE manufactured heater kits.
