AAON LN Series - Table 4- Tandem Circuited Variable Speed Compressor VFD Frequency Range; Variable Speed Compressors

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Voltage imbalance is defined as 100 times the
maximum deviation from the average voltage
divided by the average voltage.
Example:
(218V+237V+235V)/3 = 230V, then
100*(230V-218V)/230V = 5.2%, 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.
Variable Speed Compressors
Variable speed compressors should not be
operated outside the factory determined
frequency range. The factory determined
compressor VFD frequency range is given
below in Table 4
Table 4- Tandem Circuited Variable Speed
Compressor VFD Frequency Range
Model (LN-)
Compressor VFD
Range (Hz)
208V, 230V, 460V and 575V Units
045, 055, 060
45-65Hz
075
45-70Hz
095, 105, 120
35-60 Hz
140
35-65 Hz
No variable speed compressor shall
operate below 35 Hz. Operating
variable speed compressors outside
the frequency range specified in this
manual voids all warranties and may
result in compressor failure.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. Condenser fan
motors should all be checked by a
qualified service technician at startup
and any wiring alteration should 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