Motors Level 2 study guide
Reversing
(Blank) a shaded-pole motor is very different from reversing the usual single-phase motor. In many cases, the rotor must be removed from the housing and turned around so that the shaft exits the opposite side of the housing
Shaded-pole motors
(Blank) are commonly 1/20th HP or less and have low starting torque
115%
430.110(C)(2) Exception: A listed nonfused motor-circuit switch having a horsepower rating equal to or greater than the equivalent horsepower of the combined loads, determined in accordance with 430.110(C)(1), shall be permitted to have an ampere rating less than (blank) of the sum of all currents at the full load condition
Failure to start
430.31 General: Part III specifies overload devices intended to protect motors, motor control apparatus, and motor branch-circuit conductors against excessive heating due to motor overloads and (blank)
Higher
430.52(C)(1)Exception NO. 1: where the values for branch circuit short-circuit and ground fault protective devices determined by Table 430.52 do not correspond to the standard sizes or ratings of fuses, nonadjustable circuit breakers, thermal protective devices, or possible settings of adjustable circuit breakers, a higher size, rating, or possible setting that does not exceed the next (blank) standard ampere rating shall be permitted
thermal-magnetic
A (blank) circuit breaker uses a bi-metal strip connected in series with the load to open a circuit.
Overload
A (blank) in a motor is caused by a load that exceeds the full-load rating of the motor
Capacitor
A (blank) is a device that stores an electrical charge
split phase motor
A (blank) is a single phase AC motor that includes a run winding and a resistive start winding used in applications where starting is easy, such as fans, business machines, machine tools, and centrifugal pumps
Three-pole Rheostat
A (blank) is a switch with tapped resistors used to switch a set of resistors in and out of a wound-rotor circuit. It can be manually controlled or motor driven
Permanent split capacitor motor
A capacitor run motor is also known as a (blank)
180°/120°
A single phase stator is nearly identical to a three phase stator, except that the windings in the single-phase stator are placed (blank) apart in the slots. The windings in the three-phase stator are placed (blank) apart
6000A
Cartridge fuses are available with amperage ratings from 0 amperes to (BLANK)
Compound
DC (blank) motors are used mostly for special applications that require constant speed under load and high starting torque
Drum switch
If a capacitor-start motor is to be reversed often, then a (blank) or foot switch can be used to reverse the current through the start with respect to the run windings
Shunt field
In a compound wound generator, the (blank) is normally stronger than the series field
90 mechanical degrees
In a two-pole single phase motor, the start winding is placed (blank) from the run windings in a 2 pole motor
Start/Run
In many cases, a single-phase motor is constructed with both (blank) and (blank) winding in the stator
overcurrent protection
The NEC requires (blank) of motor installations
Black and Red/ T5 and T8
To reverse the direction of most single phase motors, all that is necessary is to switch the two start leads in the circuit. These leads will be colored (Blank) or marked (blank)
40%
When the split phase motor is turned OFF (power removed), the centrifugal switch recloses at approximately (BLANK) of full-load speed
Centrifugal switch
When the split phase motor reaches approximately 75% of full speed, the (blank) opens, disconnecting the start winding from the circuit
Resistance
Wound rotor starters usually have one or more timers used to automatically remove (blank) from the rotor circuit