Reznor R6GF Unit Installation Manual - Manual (Page 12)

12
Checking Heat Anticipator Settings
• Add the current draw of the system components.
OR
• Measure the current flow on the thermostat R-W
circuit after the circulating blower motor has started.
Set the heat anticipator according to the thermostat
manufacturer’s instructions for heat anticipator settings.
Heating Configurations
This furnace is factory configured for two stage gas heating
operation with a two stage heating thermostat. Connect
the low voltage thermostat White & brown wires to W1
& W2, between the unit low voltage terminal board and
thermostat sub-base.
To operate with a single stage heat thermostat, only
connect the low voltage thermostat White wire between
W1 on the unit low voltage terminal board and thermostat
sub-base. Reposition the automatic heat staging jumper
located on the ignition control module from NONE to 5 or
10 for the desired delay in minutes before the gas furnace
will automatically move to high heat operation. See Figure
11B (page 28).
NOTE: When low fire on the gas valve is energized,
the furnace operates in low fire mode at a lower blower
speed and the timer begins its delay function. If the room
thermostat is not satisfied before the timer activates, the
furnace will stage to high fire. The inducer motor and blower
will ramp to a higher speed until the thermostat is satisfied.
Configuring the Variable Speed Blower
The variable speed blower has been designed to give
the installer maximum flexibility for optimizing system
performance, efficiency, and comfort. It is equipped with
a microprocessor-controlled variable speed motor that is
pre-programmed to deliver optimum airflow in a variety of
conditions and system configurations. Because the blower
can be configured in many ways, it is important to read
and follow all instructions carefully.
CAUTION:
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.
Before operation, the variable speed blower must be
configured to match the unit with the system, climatic
conditions, and other system options. With the blower
installed and configured properly, the furnace will gradually
change speed in response to changes in system variables
such as thermostat settings, duct static, filters, etc. The
variable speed blower is configured by setting the heat,
cool, and adjust jumpers located on the ignition control
board as described below. See Figure 11B (page 28).
Selecting Cooling Airflow
The cooling airflow is selected by setting the Cool and
Adjust jumpers on the ignition control board. Table 10
(page 25) lists the recommended airflow values (CFM) and
selector tap settings for each nominal system capacity. All
airflows for other modes of operation (except secondary
gas heat) are determined by this basic setting. For
maximum capacity, generally, a selection at or near the
top of the CFM range for that nominal capacity is best.
NOTES:
• The CFM values listed in Table 10 are not dependent
on duct static pressure. The motor automatically
compensates (within the limits of the motor) for changes
in duct static pressure.
• If coil icing occurs, the basic cooling airflow selected
may be too low. Verify the selected setting is within the
range shown in Table 10 and the system is properly
charged. If icing continues, raise the selected airflow
to the next higher tap.
• For maximum dehumidification and energy efficiency,
select an airflow near the middle or bottom of the CFM
range for that nominal capacity.
• The 2-stage cooling feature of the unit requires
modulating the airflow. The unit will automatically adjust
the airflow to the appropriate rate when the unit capacity
changes.
Selecting Gas Heating Airflow
The heating airflow is selected by setting the heat jumper
to the desired tap (A,B,C, or D) located on the ignition
control board. Refer to Table 11 (page 25) and select a
Table 4. Thermostat Wire Gauge
Thermostat
Wire Gauge
Recommended T-Stat Wire
Length (Unit to T-Stat)
2-Wire
(Heating)
5-Wire
(Heating/Cooling)
24 55 25
22 90 45
20 140 70
18 225 110
COPPER WIRE SIZE — AWG
(1% Voltage Drop)
Supply Wire Length-Feet Supply Circuit
Ampacity
200 150 100 50
6 8 10 14 15
4 6 8 12 20
4 6 8 10 25
4 4 6 10 30
3 4 6 8 35
3 4 6 8 40
2 3 4 6 45
2 3 4 6 50
2 3 4 6 55
1 2 3 4 60
Wire Size based on N.E.C. for 60° type copper conductors.
Table 3. Copper Wire Size