Questions and Verified Complete Solutions By
Expert
What material should be used for seating brushes?
Sandpaper
Readings on the meter appear to be inaccurate, what should you do?
Test meter
A machine that converts mechanical energy into electrical energy
Generator
What is the purpose of interpoles in a motor?
Helps prevent neutral planes from shifting
In the basic loop circuit generator armature supplies DC power to what DC
elevator hoist motor component?
Motor Armature
If you have leakage resistance to ground, what will you use to test?
Megger
What kind of device would you use to measure current without disconnecting
wiring?
Clamp on ammeter
What is the synchronous speed of 3 phase, 60 Hz, 6 pole motor?
1200 RPM
Before attempting to measure resistance in an unknown resistor in a circuit, what
must be done?
, Isolate from one side
What is the method used to resolve residual magnetism to an exitor?
Flashing the field
What is the inherent current limiter present for a rotating motor armature called?
CEMF
In order to protect internal circuits, how is the 10 amp input jack on a digital
multimeter usually protected?
Fused
What is the field protective relay in series with?
Motor shunt field
What material is used as insulation between the commutator and the armature
shaft?
Mica
What elements make up commutator film?
Copper oxide film, graphite film, free graphite particles and waters vapor components
What does it mean when saturation occurs?
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?
Ohmmeter
When should lubrication of motor bearings be done?
Not running
What would be the result if a meter set to current and connected to a voltage
source?
Blow fuse
When commutation is good, what color is the commutator?
Chocolate
What is a precision shunt used for measuring?
Current
On a reversible D.C. door operator motor, what angle is the brush mounted?
Radially, straight up and down
What is the significance of the meter specification of ohms per volt?