Disconnect ALL power before servicing.
Multiple power sources may be present.
Failure to do so may cause property damage,
personal injury or death.
Airflow Measurement and Adjustment
Please review the ductwork section before proceeding with the
airflow measurements and adjustments in this section.
The unit blower curves (see Specification Sheets) are based on
the external static pressure (ESP per in./W.C.). The duct openings
on the unit are considered internal static pressure. As long as
ESP is maintained, the unit will deliver the proper air up to the
maximum static pressure listed for the CFM required by the
application (for example, home, building, etc.).
In general, 400 CFM per ton of cooling capacity is a rule of
thumb. Some applications depending on the sensible and latent
capacity requirements may need only 350 CFM or up to 425 CFM
per ton. Check condition space load requirements (from load
calculations) and equipment expanded ratings data to match
CFM and capacity.
After the unit is set and the ductwork completed, verify the ESP
with a 1" (2.5 cm) inclined manometer with pitot tubes or a
Magnahelic gauge and confirm CFM to blower curves in the
Specification Sheets. All units have 3-speed blower motors. If the
low speed is not utilized, the speed tap can be changed to
medium or high speed.
NOTE: Never run CFM below 350 CFM per ton. Evaporator
freezing or poor unit performance is possible.
Adjusting Speed Tap for Indoor Blower Motor
Adjust the CFM by changing the 24V low voltage lead at the
speed terminal block on the motor. (T1—Low Speed, T2 and
T3—Medium Speed, T4 and T5—High Speed).
NOTE: Factory set T1 (G, Fan), T2 (Cool/High cool), T3 (W2 Electric
Heat), T4 and T5 reserved for high static (Cool/High Cool) and W2.
The ECM control board is factory-set with the DIP Switch 4 in the
"ON" position for single stage units and to the "OFF" position for
the 2-stage units. All other DIP switches are factory-set in the
"OFF" position. For most applications, the settings are to be
changed according to the electric heat size.
The ECM motor provides many features not available on the
traditional PSC motor. These features include:
Soft Start and Stop
Improved Humidity Control
Circulating Air Blower
ECM Motor Speed Adjustment
Each ECM blower motor has been preprogrammed for operation
at 4 distinct airflow levels when operating in Cooling/ Heat Pump
mode or Electric Heat mode. These 4 distinct levels may also be
adjusted slightly lower or higher if desired.
The adjustment between levels and the trim adjustments are
made by changing the DIP switch(s) either to an OFF or ON
position. See Blower Performance Data charts.
WGPH45 DIP Switch Functions
The ECM motor has an electronic control that contains
8 2-position DIP switches. The function of these DIP switches is
shown in the following chart.
DIP Switch Number
For WGPH4524-43 models, DIP Switch 4 must be set to ON. DIP
Switch 4 must be set to OFF for 2-stage compressor models
WGPH4549-60. DIP Switch 4 ON energizes Y1 signal to the ECM
motor anytime Y/Y2 is energized. The indoor motor will not
operate properly if switch is not set correctly for the model.
WGPH CFM Delivery and Adjustments
See "Circulating Air Blower" for CFM output, adjustments and
DIP switch settings.
WGPH Thermostat Fan Only Mode
During Fan Only operations, the CFM output is 50% of the
high-stage cooling setting.
WGPH Humidity Control
When using a Humidistat (normally closed), cut jumper PJ6 on
the control board. The Humidistat will affect both low-stage and
high-stage cooling airflow by adjusting the airflow to 85%.
WGPH 2-Stage Heating
When using staged electric heat, cut jumper PJ4 on the control
WGPH Thermostat Wiring
Use the thermostat wiring diagrams provided with the thermostat
when making these connections.
Cooling and Heat Pump CFM
CFM Trim Adjust