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54 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What HP do most single phase motors come in? |
1/6-3/4 HP Also come in sizes 1/100 to 15HP |
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4 types of split phase motors? |
Resistance split-phase motor Capacitor-start motor Permanent-split capacitor motor Two-value capacitor motor |
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What is a resistance split-phase motor? |
uses two stator windings with different values of resistance and inductance to create a phase angle between the two currents in the stator |
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Components of split phase motor? |
Stator Frame Rotor Centrifugal switch |
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What is stator made out of? |
Laminated steel core with slots to hold the insulated windings. The run windings are constructed of a larger insulated copper conductors mounted in rotor Start windings are smaller conductors with fewer turns |
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How does a centrifugal switch work |
Contacts open when motor is at about 75% speed. Contacts are opened due to centrifugal force |
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How is a centrifugal switch wired? |
Wired in series with start winding |
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To determine speed of motor, what is the formula for RPM? |
Frequency x supply voltage divided by Poles
60Hz is what we deal with |
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T5 & T8 |
Just know it |
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T5 & T8 wires when reversed on a resistance split phase motor cause? |
The direction of rotation to change |
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Starting torque of capacitor motors is |
High |
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What else could capacitors be used for? |
Starting pumps Refrigeration compressors Air compressors |
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Permanent Split capacitor motor? |
Same as capacitor start motor but the capacitor hangs out and helps the motor spin and remains in circuit |
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Perm. Split capacitor motor winding connections |
Can be reversed by interchanging aux winding connections Most can be reversed while running (no centrifugal switch) |
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Permanent split capacitor motors are also used for? |
Garage doors Washington machines |
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What is a capacitor-start induction-run motor? |
A motor that uses a capacitor to create a phase angle between main and auxiliary windings when starting |
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How is the capacitor start motor similar to resistance motor? |
Similar construction with: Squirrel-cage rotor Centrifugal switch Frame (aside from capacitor mount) |
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How is it different? |
May use current sensing relay instead of centrifugal switch Aux winding and main winding has same turns. Capacitor |
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How does the capacitor work with the motor? |
Capacitor stores power and uses it on start up to create wider phase angle between main and auxiliary current windings. The capacitor stops supplying power when motor is up to 75% speed |
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Ok and ? |
Causes the current in start winding to lead applied voltage as the current in main winding lags the voltage. The two currents are now out of phase by 90 degrees which will start the motor |
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Capacitor AC or DC current? |
AC |
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How is a capacitor connected in circuit with windings? |
Connected in series with auxiliary winding and centrifugal switch |
Connected in series with auxiliary winding and centrifugal switch |
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Starting torque for a capacitor start motor? |
250-450% of rated running torque |
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Sizes for capacitor start motors? |
1/8 to 10HP 120V, 240V, 120/240V |
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Two-value capacitor motors |
Best performance motor. Combines benefits of capacitor start motor and permanent capacitor motor |
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Shaded pole motor is a |
Variable speed motor |
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How does a shaded pole induction motor work? |
Magnetic field shifts from one pole face to the other when starting (non-shaded to shaded side |
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Where would you find a shaded-pole motor? |
Inducer motor on furnace Bathroom fan motor Fridge |
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What sizes does two-value motor come in? |
1/4 - 15HP |
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Starting torque for resistance split phase motors? |
125-150% of rated running torque |
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Most common phase angle for resistance split phase motor? |
30% |
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Which motor has 2 capacitors? |
Two value motor |
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Which motor smooths out voltage? |
Permanent split capacitor motor |
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Which motors don’t have a centrifugal switch? |
Permanent split motor & shaded pole |
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Slow starting variable speed motor? |
Shaded pole |
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What is a capacitor made out of? |
2 conductive plates (Anode And Cathode) separated by dialectic |
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Which motor does not cut capacitor from circuit when running? |
Permanent split capacitor motor |
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Which motor has the same # of turns on aux and main windings? |
Capacitor-start induction run motor |
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What is capacitor start motor used for? |
Pumps, refrig compressors, air compressors |
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Which winding determines rotation direction of motor? |
Aux windings |
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What may be used instead of a centrifugal switch? |
Current sensing relay |
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Starting torque for capacitor start motor? |
250-450% |
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How is phase angle created in resistance split phase motor? |
Two stator windings w different values of resistance and inductance |
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How to change rotational direction of resistance split phase motor (single voltage) |
Interchange leads to main or aux |
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How about for dual voltage? |
Reverse t5 & t8 |
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Sizes of capacitor start motor? |
1/8- 10HP |
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Which motor has aux windings designed for continuous use? |
Permanent split phase motor |
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Permanent split phase motors AKA |
Capacitor run motors |
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Which motor is most expensive? |
Two value capacitor motor |
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Where are two value capacitor motors found? |
Blower motors, ac compressors, submersible pumps |
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What size does the permanent split capacitor motor come in? |
1/20hp-1/2hp |
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How is speed controlled on shaded pole motors? |
Auto transformers |
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Sizes of shaded pole motors? |
1/100 - 1/6HP |
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