11
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 (GR) is fixed at TB1-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.
High Cool Y2, Purple (PU) is movable and set to TB1-T3.
High Heat W2, Brown (BR) is movable and set to TB1-T3.
These wires can be moved together or separately and
placed on any unoccupied terminal.
Note: YL can be moved to taps T2-T3 as long as YL does
not share the tap with PU. WH can be moved to tap T3 as
long as WH does not share the tap with BR.
High Static Motor Drive
Fan speed for G (GR), is fixed at TB1-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-T6
High Cool Y2, Purple (PU) is movable and set to TB1-T3
High Heat W2, Brown (BR) is movable and set to TB1-T8
These wires can be moved together or separately and
placed on any unoccupied terminal.
Note:
If operating the unit below 0.8” ESP move PU wire
to T2.
Note:
YL can be moved to taps T2-T3 as long as YL does
not share tap with PU. WH can be moved to tap T7 as long
as WH does not share the tap with BR
When Heat is called TB1-W1 will also call TB1-DH
activating the second set of taps T6-T10. If cooling and
heating is called at the same time heating will take priority
and T6-T10 will be chosen by default.
Note: For proper operation Y2 and W2 should have a
higher speed setting than the G, Y1 and W1 speed setting.
Utilization Voltage -
The voltage of the line terminals
of the equipment at which the equipment must give fully
satisfactory performance. Once it is established that supply
voltage will be maintained within the utilization range under
all system conditions, check and calculate if an unbalanced
condition exists between phases. Calculate percent voltage
unbalance as follows:
Three Phase Models Only
3) PERCENT VOLTAGE
UNBALANCE
2) MAXIMUM VOLTAGE DEVIATIONS
FROM AVERAGE VOLTAGE
1) AVERAGE VOLTAGE
HOW TO USE THE FORMULA:
EXAMPLE: With voltage of 220, 216, and 213
1) Average Voltage = 220+216+213=649 / 3 = 216
2) Maximum Voltage Deviations from Average Voltage = 220 - 216 = 4
3) Percent Voltage Unbalance = 100 x
=
= 1.8%
Percent voltage unbalance MUST NOT exceed 2%
.
4
216
400
216
= 100 X
AIR FLOW ADJUSTMENTS
When the final adjustments are complete, the current
draw of the motor should be checked and compared to
the full load current rating of the motor. The amperage
must not exceed the service factor stamped on the motor
nameplate.
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, see Table below. 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.
Minimum Nominal Maximum
DRC036 DRH036
900
1150
1500
DRC048 DRH048
1200
1500
2000
DRC060 DRH060
1500
1850
2500
DRC072 DRH072
1800
2200
3000
Model
High Stage Airflow Setting, CFM
(without electric heat)
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
numerical speed tap.
