11
If an economizer is installed, check the unit operating
balance with the economizer at full outside air and at
minimum outside air.
High stage airflow setting to be between 300 and 500 CFM
per ton. For models with electric heat the total airflow must
not be less than that required for operation of the electric
heaters. See Appendix D for minimum airflow for specific
electric heaters.
NOTE: Never run CFM below 300 CFM per ton,
evaporator freezing or poor unit performance is
possible.
Standard Static Drive Motor
Adjust the CFM for the unit by changing the position of
the low voltage leads on the terminal block TB1. Refer to
Appendix A for blower performance at each speed tap
NOTE: If more than one lead is energized
simultaneously, the motor will run at the higher
speed tap.
Standard Static Drive Motors are set up to use motor
speed taps T1-T5 Refer to Appendix A for blower
performance at each speed tap.
Fan speed for G (Fan) is fixed at TB-1-T1 and cannot be
moved.
Low Cool Y1, Yellow (YL) is movable and set to TB1-T1.
Low Heat W1, White (WH) is movable and set to TB1-T2.
These wires can be moved together or separately and
placed on any unoccupied terminal.
NOTE: On units with DDC controls installed,
refer to the DDC User Manual for details on
making airflow adjustments. Individual settings
are available for Fan Only, Low Stage Cooling,
High Stage Cooling, Low Stage Heating, and High
Stage heating which can be adjusted as needed to
meet airflow requirements.
INDOOR MOTOR TAPS
T1
T2
T3
T4
T5
FAN (GR)
X
-
-
-
-
COOLING (YL)
-
X
X
X
X
HEATING (BR)
-
-
X
X
X
RECOMMENDED SPEED TAPS 3-5 TON STANDARD STATIC
NOTE: If more than one lead is energized
simultaneously, the motor will run at the higher
speed.
INDOOR MOTOR TAPS
T1
T2
T3
T4
T5
T1'
T2'
T3'
T4'
T5'
FAN (GR)
X
-
-
-
-
X
-
-
-
-
COOLING (YL)
-
X
X
X
X
-
X
X
X
X
HIGH HEAT (BR)
-
X
X
X
X
-
X
X
X
X
INDOOR MOTOR TAPS
T1
T2
T3
T4
T5
T1'
T2'
T3'
T4'
T5'
FAN (GR)
X
-
-
-
-
X
-
-
-
-
COOLING STG1 (YL)
-
X
-
-
-
-
X
-
-
-
COOLING STG2 (PU)
-
-
X
X
X
-
-
X
X
X
HIGH HEAT (BR)
-
-
X
X
X
-
-
X
X
X
RECOMMENDED SPEED TAPS 3-5T HIGH STATIC
RECOMMENDED SPEED TAPS 6T STANDARD AND HIGH STATIC
NOTE: For motors with 10 speed taps DH = 0VAC
uses speed taps T1-T5. DH = 24VAC uses speed taps
T1’-T5’.
Refrigeration System Checks
This unit is equipped with thermal expansion valves.
Ensure the hold-down bolts on the compressor are secure
and have not vibrated loose during shipment. Check that
the vibration grommets have been installed and visually
check all piping for damage and leaks and repair if
necessary. The entire system has been factory charged
and tested, making it unnecessary to field charge. Factory
refrigerant charge is shown on the unit’s nameplate.
To confirm charge levels or, if a leak occurs and charge
needs to be added to the system, it is recommended to
evacuate the system and recharge refrigerant to the units
nameplate specifications. This unit has been rated in the
cooling mode at the AHRI rated conditions of indoor (80°F
db / 67°F wb) and outdoor (95°F db). While operating at
this condition the superheat and subcool should range
as shown in the superheat and subcool table. Superheat
should be measured at the suction service port located
near the compressor. Subcool should be measured at the
liquid line service port.
TONNAGE
SUPERHEAT (°F)
SUBCOOLING (°F)
3
8 - 10
14 - 16
4
8 - 10
14 - 16
5
11 - 13
15 - 17
6
9 - 11
17 - 19
UNIT SUBCOOLING AND SUPERHEAT
Start-Up Procedure and Checklist
Begin with power turned off at all disconnects.
Air Conditioning Start-Up Procedure
1. Ensure the thermostat is set to OFF and Fan is set
to Auto.
2.
Inspect all registers and set them to the normal open
position.
3. Turn on the electrical supply at the disconnect.
4. Turn the fan switch to the “ON” position. The blower
should operate after a 7 second delay.
5. Turn the fan switch to “Auto” position. The blower
should stop after a 60 second delay.
