11
√ Verify the thermostat is wired correctly. Make sure all low
voltage wires are securely connected.
√
Verify the power supply branch circuit overcurrent
protection is sized properly.
√
Verify filter is properly and securely installed.
IMPORTANT: Before starting the unit, install the initial
charge on units that are factory shipped with a nitrogen
holding charge:
1. Read all installation instructions first.
2. Purge the nitrogen holding charge.
3. Evacuate the unit to 350 - 500 microns.
4. Allow the unit to remain under vacuum for at least 30
minutes.
5. Weigh in the proper amount of new (or reclaimed)
refrigerant. Refer to the air conditioner or heat pump
installation manual for the proper type and quantity of
refrigerant.
Air Circulation
Running the Blower Continuously
Set the thermostat’s system mode to OFF and the
thermostat’s fan mode 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 ducts.
Selecting Continuous Low Speed Fan Operation
(Standard Blower)
The air handler is equipped with an option of continuous low
speed fan operation. When G is energized without Y/Y2, the
air handler will operate using the cooling speed. With G &
Y/Y2 or Y/Y2 energized, the air handler will operate in the
selected cooling speed (including 40 sec blower-off delay).
Turning the Blower Off
Set thermostat’s fan mode to AUTO, the blower will shut
down immediately.
System Cooling
1. Set the thermostat’s system mode to COOL and fan mode
to AUTO. Lower the thermostat’s temperature mode below
room temperature and observe that the blower energizes.
Check the air being discharged at the register is cooler
than room temperature. Verify unit refrigerant pressures
are in order. Blower should be turning in direction indicated
by arrow.
NOTE: DO NOT alter unit wiring. Listen for any unusual
noises. Locate the source and correct as needed.
2. Allow the unit to run for several minutes and then set the
thermostat’s temperature above room temperature. Verify
the blower cycles off with the thermostat.
System Heating
1. Set the thermostat’s system mode to HEAT and the fan
mode to AUTO. Increase the thermostat’s temperature
above room temperature and observe that the blower
energizes. Check the air being discharged at the register
is warmer than room temperature.
2. Allow the unit to run for several minutes and then set the
thermostat’s temperature below room temperature. Verify
the blower cycles off with the thermostat.
Selecting Minimum Electric Heat Airflow
The minimum electric heat airflow setting controls the
minimum air flow that will be produced whenever electric
heater kits are used. When the electric heater kit is energized
along with a heat pump, the airflow may be higher depending
on the basic cooling/heat-pump airflow setting. The minimum
electric heat airflow is selected by setting switches 1, 2, 3, &
4 on B64EM models. B64VM models automatically set the
heating speed based on the amount of installed heat. The
A/B switch must be set appropriately for the unit cabinet
size. For C-sized cabinets, the A/B switch can be set in
either position. The remaining 3 HEAT switches have no
function. Switch settings are listed in Table 6, (page 16) or
Table 9, (pages 19 and 20).
NOTES:
• For B64EM Models, the minimum electric heat airflow
setting may be set higher, but must never be set lower
than the setting shown in Table 7, (page 17).
• Variable speed motor control boards do not support non-
electric heat because the heating air flow cannot be set
independently.
Blower Configurations
Determining Nominal System Capacity
To select the appropriate airflows for the air handler, the
nominal system capacity must be known. The nominal
system capacity is always the nominal capacity of the
outdoor unit. However, in some situations the nominal system
capacity may not be the same as the nominal capacity of
the air handler. Always refer to the nominal capacity of the
outdoor unit to determine the nominal system capacity. Use
Table 8, (page 18)
as a guide for acceptable airflow CFM
(dependent on air handler cabinet size and nominal capacity
of the outdoor unit).
NOTE: The CFM values listed in Table 9, (pages 19 and
20)
are not dependent on duct static pressure. The VSHE
motor automatically compensates for changes in duct static
pressure (within the limits of the motor).
High Efficiency Units (Variable & Fixed Speed)
IMPORTANT! This air handler has been designed to give the
installer maximum flexibility to optimize system performance,
efficiency, and comfort. Because there are so many different
ways to set up the air handler it is important to read and
follow these directions carefully.
B64EM & B64VM air handlers use high efficiency circulating
air motors that come in two variations and both are
controlled differently. The variable speed motor control board
(Figure 15)
controls the airflow at a constant CFM when
paired with a separate control board. The fixed speed unit
has a single integrated control board (Figure 14 (page 23))
that controls the torque of the motor.
Before operation, the air handler must be configured to
match the unit with the system, system options, and climatic
conditions. During normal operation, the motor will gradually
change speeds during start-up, shut down, when thermostat
inputs change, and when the duct static pressure changes
(vents closed or opened, filter clogging, etc.). The air handler
is configured by setting the selector switches and removing
jumper connectors.
Basic Heating Airflow for Variable & Fixed Speed
Fixed & variable speed motor control boards (Figure 14 &
Figure 15 (page 23))
contain a set of dip switches for setting
the blower speed. For B64EM models, pins 1-4 set the
speed for heating. For B64VM models, the A/B switch must
be set for the appropriate cabinet size (either setting can be
used for C-size cabinets). The airflow is set automatically
based on the amount of installed heat. To determine
the appropriate switch settings for your installation, see
Table 6, (page 16),
or Table 9, (pages 19 and 20).
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