AAON CF Series - 3-Phase Rotation and Voltage Imbalance

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Power wiring is to the unit terminal block or
main disconnect. All wiring beyond this point
has been done by the manufacturer and cannot
be modified without affecting the unit's
agency/safety certification.
All units require field supplied electrical
overcurrent and short circuit protection.
Device must not be sized larger than the
Maximum Overcurrent Protection (MOP)
shown on the unit nameplate.
Supply voltage must be within the min/max
range shown on the unit nameplate. Available
short circuit current must not exceed the short
circuit current rating (SCCR) shown on the
unit nameplate.
Three phase voltage imbalance will cause
motor overheating and premature failure. The
maximum allowable imbalance is 2%.
Voltage imbalance is defined as 100 times the
maximum deviation from the average voltage
divided by the average voltage.
Example:
(221V+230V+227V)/3 = 226V, then
100*(226V-221V)/226V = 2.2%, which
exceeds the allowable imbalance.
Check voltage imbalance at the unit disconnect
switch and at the compressor terminal.
Contact your local power company for line
voltage corrections.
NOTE: A qualified technician must check for
proper motor rotation and check fan motor
amperage listed on the motor nameplate is not
exceeded. Motor overload protection may be a
function of the variable frequency drive and
must not be bypassed.
Wire control signals to the unit’s low voltage
terminal block located in the controls
compartment.
If any factory installed wiring must be
replaced, use a minimum 105°C (221°F) type
AWM insulated conductors.
3-PHASE ROTATION
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. Condenser fan
motors must be checked by a qualified
service technician at startup and any
wiring alteration must only be made at
the unit power connection. Variable
frequency drives are programmed to
automatically rotate the fan in the
correct rotation. Do not rely on fans
with variable frequency drives for
compressor rotation.
CAUTION
SEALING ELECTRICAL ENTRIES
Installing Contractor is responsible for
proper sealing of the electrical entries
into the unit. Failure to seal the entries
may result in damage to the unit and
property.
CAUTION
Three phase voltage imbalance will
cause motor overheating and
premature failure.
CAUTION