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14 Cards in this Set
- Front
- Back
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The output voltage of a PWM VFD consist of |
Pulses of varying period only |
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A VFD which is varying its output frequency in response to feedback from a sensing device is running |
Closed loop |
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The carrier frequency of a variable frequency drive is the |
Frequency of the dc pulses that are switched on or off |
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Variable frequency drives produce a pure sine wave output? |
False |
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What filters the VFDs simulated sine wave output |
The inductance of the motor winding |
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A nonlinear load is a load: |
Whose impedance changes as voltage changes |
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How much power is required for a constant torque load running at half speed |
1/2 full load |
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What is not considered a variable torque load |
Fans Blowers Centrifugal pumps |
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Which of the harmonic currents have the greatest effect on 3 phase systems |
Low odd numbered harmonics |
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Variable frequency drives produce a pure sine wave output? |
False |
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What does the letters PWM mean |
Pulse width modulation |
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What is classified as an inverter duty motor |
Totally enclosed blower cooled (TEBC) motor |
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What is a constant torque load device |
Conveyer (same torque at any speed) |
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Adjusting the V/Hz setting on a VFD will directly determine the |
Torque |
