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Worksheets26311-20 motor controls
Total questions: 20
Worksheet time: 10mins
Which of the following are primarily designed for use with inductive motor loads and to withstand the interrupt current of a locked rotor?
NEMA-rated contractors/motors starters
Definite-purpose contractors/motors starters
Lighting contactors
IEC-rated contactors/motors starters
A relay designated as a 3PDT-SB relay
Has three N.O. (Normally open) contacts
Has three N.O. (Normally open) and three N.C. (Normally closed) contacts
Is a single-throw type
Is a double-break type
The component marked 1 in the figure provided is a(n)
Melting-alloy heater assembly
Overload contact
Load terminal
Reset terminal
The components marked 2 in the figure provided are
Overload contacts
Reset terminals
Melting-alloy heater assemblies
Load terminals
A NEMA-rated motor starter consists of an enclosure containing
One or more magnetic contactors with associated overloads relays
Magnetic contactor hard and stop and start pushbuttons
Disconnect switch and magnetic contactor
A circuit breaker and magnetic contactor
if the heater is in a fixed IEC bimetallic overload relay fails
The heater must be replaced with a heater of the same size
The entire overload relay must be replaced
It and all the other heaters in the overload relay must be replaced
The heater can be replaced with a heater of the same size or one that is slightly smaller
Inching is also referred to as
Throttling
Jogging
Stepping
Plugging
The nameplate on a motor indicates that the motor has an FLC of 10A how do I end a service factor (SF) of 1.15. How much additional current can this motor safely handle for intermittent power demands?
1.5A
1.75A
2.25A
3.5A
Most transient suppression modules consist of an RC circuit that is designed to suppress coil voltage transients to approximately what percentage of the peak coil supply voltage?
75%
100%
150%
200%
If a duty cycle includes only non-inductive or slightly inductive loads, select an
AC-1 rated motor control device
AC-2 rated motor control device
AC-3 rated motor control device
AC-4 rated motor control device
A 240-to-24v transformer is most likely to serve a
Motor control circuit
Line-voltage lighting circuit
Motor power circuit
Machine tool
Symbol F in the figure provided represents a
Float switch
Temperature switch
Pressure switch
Foot switch
A retroreflective scan is the scanning method in which
The light beam transmitted from the transmitters reflected back to the receiver by the target to be detected
The target to be detected passes between the transmitter and receiver, interrupting the light beam
The target is detected as it passes between the photoelectric sensor and a reflector
The receiver response only to Depolarized light reflected from the corner cube reflector, or polarized sensitive tape
Symbol B in the figure provided represents a
Float switch
Temperature switch
Pressure switch
Foot switch
A general-purpose NEMA enclosure is Type
1
3
4
12
In the figure provided, the belt runoff switch ZS108A is connected to junction box JB108 by cable
C108G
C108H
C108J
C108K
The relay logic and truth table shown in the figure provided represents a(n)
NAND function
OR function
NOR function
AND function
On a ladder diagram, pilot devices are located in the
Termination section
Decision section
Signal section
Action section
A NEC Article 430, part IX covers
Hazardous locations
Overload protection
Motor disconnects
Enclosures
In the figure provided, the purpose of the M1 normally closed contacts shown in the control circuit is to
Prevent the drain pump from operating when the fill pump is operating
Provide memory for the start switch
Prevent the fuel pump from operating when the drain pump is operating
Provide memory for the float switch
