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Turning the Blower Off
Set thermostat's fan mode to Auto, the blower will shut
down immediately.
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 capacity rating
of the air handler. Always refer to the capacity rating of the
outdoor unit to determine the nominal system capacity.
Selecting Continuous Low Speed Fan Operation
The B6BV series air handler is equipped with the option of
continuous low speed fan operation. When G is energized
without Y/Y2, the air handler will operate using the heating
speed. With G & Y/Y2 or Y/Y2 energized, the B6 electric
furnace will operate in the selected cooling speed (including
40 sec blower-off delay). NotE: To achieve continuous
low speed fan operation G must be connected at the B6
electric furnace.
Proper Blower Speed for Multi-Speed Units
The blower speed is preset at the factory for operation
at the same speed for heating and cooling, by using the
jumping terminal on the blower motor and connecting it
to the desired speed with both the red and black wires
connected to the jumping terminal.
NotES:
• The control board is programmed with a 40 second
off delay in the cooling mode for optimum system
performance and efficiency.
• When using a 20 kw electric heat kit in a downflow
installation, the blower must be set for high speed for
both heating and cooling.
cAutIoN:
to avoid personal injury or property damage,
make sure the motor leads do not come into
contact with any uninsulated metal components
of the unit.
For optimum system performance and comfort, it may
be necessary to change the factory set speed. Refer to
Tables 6, 7a, or 7b (page 14) for airflow data. To change
the blower speed:
1. Disconnect all electrical power to the unit and remove
the upper door.
2. Remove the black and red wires from the blower motor
jumping terminal. Discard the blower motor jumping
terminal.
3. Connect the heating speed wire (red) and the cooling
speed wire (black) to the desired blower speed marked
on the terminal block of the blower motor.
10
Standard 4-speed motors:
• Terminal 2 = High speed
• Terminal 3 = Medium High speed
• Terminal 4 = Medium Low speed
• Terminal 5 = Low speed
4. Replace the upper door and secure it to the unit.
5. Restore power to the unit.
High Efficiency - Fixed Speed Units
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.
B6BV air handlers use high efficiency circulating air motors
The fixed speed motor control board (Figure 13, page 17)
controls the torque output of the motor.
Before operation, the air handler must be configured to
match the unit with the system, system options, and climatic
conditions. When configured, the air handler responds
directly to the thermostat inputs, as well as the optional
humidistat (see page 11). 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 switcheson the control board.
Selecting Basic Heating Airflow
The fixed speed motor control board (Figure 13) contains
a set of dip switches for setting the blower speed. Use pins
1 to 4 to set the blower speed for heating and pins 5 to 8
to set the speed for cooling. To determine the appropriate
switch settings for your installation, see Table 7b (page 14)
NotE: The minimum electric heat airflow setting may be
set higher, but must never be set lower than the setting
shown in Table 6 (page 14).
Selecting Basic Cooling / Heat Pump Airflow
The basic cooling/heat-pump airflow is controlled by setting
switches 5 - 8 on the thermostat input board (mounted
on the blower). All airflows for other modes of operation
(except electric heat) are determined by this basic setting.
FAN ONLY would deliver 50% of the selected cooling
airflow. Table 7b (page 14) lists the basic airflow values
versus the airflow selector switch settings and ranges of
basic air flow settings.
• When operating in the heat pump mode, a higher
basic airflow setting will increase the energy efficiency
and capacity but will also decrease the supply air
temperature.
• For maximum capacity and energy efficiency, select an
airflow at or near the top of the range for that nominal
capacity.
• For maximum dehumidification, select an airflow near the
middle or bottom of the range for that nominal capacity.
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