What material should be used for seating brushes? - Answer- Sandpaper
Readings on the meter appear to be inaccurate, what should you do? - Answer- Test
... [Show More] meter
A machine that converts mechanical energy into electrical energy - Answer- Generator
What is the purpose of interpoles in a motor? - Answer- Helps prevent neutral planes from shifting
In the basic loop circuit generator armature supplies DC power to what DC elevator hoist motor component? - Answer- Motor Armature
If you have leakage resistance to ground, what will you use to test? - Answer- Megger
What kind of device would you use to measure current without disconnecting wiring? - Answer- Clamp on ammeter
What is the synchronous speed of 3 phase, 60 Hz, 6 pole motor? - Answer- 1200 RPM
Before attempting to measure resistance in an unknown resistor in a circuit, what must be done? - Answer- Isolate from one side
What is the method used to resolve residual magnetism to an exitor? - Answer- Flashing the field
What is the inherent current limiter present for a rotating motor armature called? - Answer- CEMF
In order to protect internal circuits, how is the 10 amp input jack on a digital multimeter usually protected? - Answer- Fused
What is the field protective relay in series with? - Answer- Motor shunt field
What material is used as insulation between the commutator and the armature shaft? - Answer- Mica
What elements make up commutator film? - Answer- Copper oxide film, graphite film, free graphite particles and waters vapor components
What does it mean when saturation occurs? - Answer- Holds all the magnetic lines of flux it can hold
What kind of meter would you use to detect a ground in the armature coils? - Answer- Ohmmeter
When should lubrication of motor bearings be done? - Answer- Not running
What would be the result if a meter set to current and connected to a voltage source? - Answer- Blow fuse
When commutation is good, what color is the commutator? - Answer- Chocolate
What is a precision shunt used for measuring? - Answer- Current
On a reversible D.C. door operator motor, what angle is the brush mounted? - Answer- Radially, straight up and down
What is the significance of the meter specification of ohms per volt? - Answer- Internal resistance at specific voltage
On the resistance scale of a digital meter, what does the lazy 8 symbol signify? - Answer- Infinity
When some of the generator output is used to supply the field current how is the generator described? - Answer- Self-exciting
When the multimeter is set to amps position the test leads are considered to be in what state? - Answer- Short circuit
What should resistance of an armature be when measured from commutator to ground with brushes removed? - Answer- High resistance
What method of armature winding is used for high current applications? - Answer- lap winding
What should always be done to protect the meter from damage when measuring unknown voltage? - Answer- Set to the highest range
To what scale should the ammeter be set in order to read a current of 2000 ma? - Answer- 10 amp
What must be done when testing a resistance to avoid readings caused by parallel circuit paths? - Answer- Remove one or two of the wire to the item being tested
0.790 MΩ indicates? - Answer- 790 kΩ
AC voltage on a voltmeter is always indicated as? - Answer- RMS
0 on voltmeter when testing a known power source indicates? - Answer- Internal fuse is blown
.250 MΩ indicates? - Answer- 250,000 MΩ
What should resistance of a motor or generator commutator be to ground with the brushes raised? - Answer- Infinite Resistance
2230Ω can also be expressed as? - Answer- 2.23 kΩ
Applied voltage on the primary leads current by? - Answer- 90°
CEMF can best be described as? - Answer- Opposes applied voltage
Eddy currents can be described as? - Answer- Circulating currents set up by magnetic induction
a 1:12 fixed voltage transformation ratio transformer is? - Answer- Step-up
How would you check for an open primary winding? - Answer- Measure resistance across the primary
If the secondary winding is open what will happen to the secondary resistance? - Answer- It will be infinity
When the secondary winding is completely shorted what happens to primary current? - Answer- Current is high
How can you reduce ripple? - Answer- More coils and commutator segments
If current carrying wire is placed perpendicular to a field by two magnets of opposite polarity what happens? - Answer- Conductor is moved at right angles to the flux from the magnetic poles
Inherent current-limiter present for a rotating armature? - Answer- CEMF
Elementary AC generator has what that DC doesn't? - Answer- Split rings
What provides the connection for the ends of the armature coils to the commutator? - Answer- Riser
Neutral plane is? - Answer- The point in a coils rotation where zero voltage is [Show Less]