Applying Drives to Single-
phase Input Application
12.3 Input Frequency and Voltage Tolerance
The single-phase current ratings are valid for 60Hz input only.
The AC supply voltage must be within the required voltage range of 240/480Vac +10% to ā
5% to maximize motor power production. Standard product with three-phase voltage input
has an allowable range of +10% to ā15%. Therefore, a stricter input voltage tolerance of
+10 to ā5% applies when using the drive with a single-phase supply. The average bus
voltage with single-phase input is lower than the equivalent of a three-phase input.
Therefore, the maximum output voltage (motor voltage) will be lower with a single-phase
input. The minimum input voltage must be no less than 228Vac for 240 volt models and
456Vac for 480 volt models, to ensure motor voltage production of 207Vac and 415Vac,
respectively.
Thus, if full motor torque must be developed near base speed (full power) it will be
necessary to maintain a rigid incoming line voltage so that adequate motor voltage can be
produced. Operating a motor at reduced speed (reduced power), or using a motor with a
base voltage that is lower than the incoming AC supply rating (ex. 208Vac motor with a
240Vac supply), will also minimize the effect of vol
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