Lennox ML193UH Installation Instructions Manual page 38

Generator Use - Voltage Requirements
The following requirements must be kept in mind when
specifying a generator for use with this equipment:
D The furnace requires 120 volts + 10% (Range: 108
volts to 132 volts)
D The furnace operates at 60 Hz + 5% (Range: 57 Hz to
63 Hz)
TYPICAL ML193UH WIRING DIAGRAM
FIGURE 60
Page 38
D The furnace integrated control requires both polarity
and proper ground. Both polarity and proper grounding
should be checked before attempting to operate the
furnace on either permanent or temporary power
D Generator should have a wave form distortion of less
than 5% THD (total harmonic distortion).