Motor Controls

A separate control circuit is typically a _____ nonpower-limited control circuit and must comply with the requirements of Article 725, Part II of the NEC. A) Class 1 B) Class 2 C) Class 3 D) Class 4

A) Class 1

A _____ overload relay is typically used with hermetic motors, and motors with short locked-rotor time capacity. A) Class 10 B) Class 20 C) Class 30 D) Class 40

A) Class 10

_____ are used to represent the function of the control circuit and the associated devices, but don't show the components of the control circuit in their actual positions. A) Ladder diagrams B) Connection diagrams C) Wiring diagrams D) Pictorial diagrams

A) Ladder diagrams

In the field, most ladder and wiring diagrams don't use numbers such as F1, F2, R1, or R3 for the auxiliary contacts. A) True B) False

A) True

Reversing any two lines (power-supply conductors) to a three-phase motor causes the motor to run in the other direction. A) True B) False

A) True

The most common types of motors used for single-phase reversing are capacitor-start motors and split-phase motors. A) True B) False

A) True

In order to properly size overcurrent protection for a control circuit, it's necessary to distinguish whether the control circuit is a _____. A) common (tapped) control circuit or a separate control circuit B) special control circuit or a different control circuit C) Class 2 or Class 3 circuit D) single-phase control circuit or a three-phase branch circuit

A) common (tapped) control circuit or a separate control circuit

An electromechanical device used for repeatedly establishing and interrupting an electric power circuit is a ______. A) contactor B) control C) float switch D) combination starter

A) contactor

The circuit of a control apparatus or system that carries the electric signals directing the performance of the controller but doesn't carry the main power current is called a ______. A) control circuit B) service C) feeder D) branch circuit

A) control circuit

Where a dual-voltage control transformer is used, and the control circuit is 120V on the secondary, the _____. A) dual primary windings are connected in series if 480V B) dual primary windings are connected in series if 240V C) dual primary windings are connected in parallel if 480V D) dual primary windings are connected in parallel at either 480 or 240V

A) dual primary windings are connected in series if 480V

Many types of overload protectors operate on the relationship between _____. A) heat and current B) the neutral conductor and the earth C) branch circuits and feeders D) voltage and wattage

A) heat and current

The motor control circuit shown in Figure 1-11 is a _____. A) ladder diagram B) connection diagram C) wiring diagram D) pictorial diagram

A) ladder diagram

Ladder diagrams are also known as _____. A) line or elementary diagrams B) schematics C) pictorial diagrams D) operating diagram

A) line or elementary diagrams

Pressing either the forward PB or the reverse PB to reverse direction while the motor is already running causes stress in the motor, and briefly causes a high current which produces abnormal heating in the motor. This is called a(n) _____. A) plugging reversal B) electrical interlock C) mechanical interlock keyboard_backspace selected B) reversing control

A) plugging reversal

16 AWG control conductors that extend beyond the motor control equipment enclosure must be protected with a protection device rated no more than _____. A) 5A B) 10A C) 15A D) 20A

B) 10A

A common abbreviation for a safety switch is _____. A) SS B) SSW C) SAS D) SSP

B) SSW

A circuit in which all the components or contact symbols are connected end-to-end (as in a continuous loop), providing only one path for current flow is called a ______. A) separate control circuit B) series circuit C) short circuit D) remote-control circuit

B) series circuit

The circuit conductors between the final overcurrent device and the outlet or equipment is a ______. A) control circuit B) common control circuit C) branch circuit D) parallel circuit

C) branch circuit

When the selector switch of a forward-reverse control circuit is in the _____ position, the forward portion of the circuit is disconnected. A) forward B) backward C) reverse D) upside down

C) reverse

Which of the following item(s) can be considered a manual control switch? A) A toggle switch. B) A safety switch. C) A drum switch. D) all of these

D) all of these

A basic 2-wire control circuit goes from a power supply, which is L1 if from the contactor (common control wiring), to a 2-wire control device such as a _____. A) float switch B) pressure switch C) temperature switch D) any of these

D) any of these

A device used to supply reduced voltage to a control circuit is called a _____. A) motor control switch B) relay C) limit switch D) control circuit transformer

D) control circuit transformer

The motor control circuit shown in Figure 1-10 is a _____. A) ladder diagram B) connection diagram C) wiring diagram D) pictorial diagram

D) pictorial diagram

A manually operated switch that uses a rotating motion for actuating a device is called a ______. A) speed switch B) pressure switch C) safety switch D) selector switch

D) selector switch