Motors Flashcards
What is the purpose for a motor on a oil burner?
Run fuel unit,run the fan,run circulating pumps,and power blowers in furnaces.
What are the basic components to a motor?
- Base
- Rotor
- Stator
- Start Windings
- Run Windings
- Start Switch
What is the base of a motor?
Frame
What is the rotor in a motor?
Part that moves.
What is the stator?
Stationary magnets and windings that create the field that cause the motor to turn.
What are start windings?
Gives motor extra power to start. Turned off when motor is at full speed.
What are run windings?
Windings that maintain shaft rotation after start windings are disconnected.
What is a start switch?
A centrifugally operated switch used in split phase and capacitor start motors opens and disconnects the start windings after the motor reaches 75%-80% of full speed.the throw out speed for a 3450RPM motor is 2800RPM. Conserves electricity.
How are motors typically rated?
Voltage,amp draw,direction of rotation,frame size and horsepower.
What is the motor flange size on modern oil burners?
M, 6”3/4
How is a start switch wired?
Internally in series with the start winding.
What are the two parts of a start switch?
Stationary switch and the governor.
What does a governor do on a motor?
Hold the switch contacts together when the motor is not running and release them when the motor gets up to speed.
What is a thermal or overload switch?
Wired in series with the motor windings and is activated with an unusual increase in temp inside the motor.
What are the two types of thermal or overload switches?
Manual and automatic
