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3E151 Set 1 V3
Question | Answer |
---|---|
What is the main advantage of the melting-alloy type overload? | Amperage rating always stays the same |
What does variable frequency drive (VFD) give an engineer? | Creates customer comfort and efficiency |
Where would a feedback control source come from for a VFD? | Internal or External |
Always do what to a VFD before attempting maintenance? | Verify unit is de-energized |
On a magnetic line starter the control circuit consists of what items? | Holding coil, Auxiliary contacts, and overload relay reset contacts |
What terminals are used to connect a three-phase motor to a magnetic line starter? | T1, T2, T3 |
How many sets of main contacts does a single phase magnetic line starter have? | 2 |
How are the contacts operated in a float switch? | Lever and float assembly |
What is the thermostat sensitive to in heating and cooling systems? | Temperature |
The hand, off, automatic switch is? | a three position switch |
A relay may be defined as? | An electromagnetic switch |
What is the function of a relay? | Open and close an electrical circuit |
Normally speaking when comparing the load circuit to the control circuit in a relay | The load circuit is shorter and made of a heavier conductor |
The power Supply is attached to what part of the motor? | Stator |
Where is electrical energy converted into mechanical energy in an electric motor? | Rotor |
What is the purpose of the skew effect on a squirrel cage motor? | Increases the torque |
Current Flow in the stator is transferred to the rotor of a three phase motor... | by magnetic induction |
What is one way to connect a three phase motor for 440 volts? | Wye, Series |