Unit 19 Test and Quiz Review

A

A ______________ overload is not affected by temperature and will open the motor circuit at a specific current rating A. magnetic B. mechanical C. thermal D. internal

D

A device that functions like a contactor, can be rebuilt, and has a motor overload protection built into it is called a ___________________. A. light duty relay B. single-pole contactor C. double-pole contactor D. motor starter

D

A device that functions like a relay, can handle a larger load through its contacts, and can have auxiliary contacts is a(n) _______________. A. overload B. pilot duty relay C. service switch D. contactor

A

A relay with a single set of contacts that close when the coil is energized is called _______________. A. single-pole-single-throw (SPST) B. double-pole-double-throw (DPDT) C. single-pole-double-throw (SPDT) D. double-pole-single-throw (DPST)

True

Fuses are used as circuit protectors, not motor protectors True or False

D

Heavier-duty motor switching relays are often made of __________________. A. nickel-plated copper B. aluminized steel C. zinc oxide D. silver cadmium oxide

C

A(n) has a magnetic coil that opens or closes one or more sets of contacts, is designed for light-duty applications, and is considered a disposable device. A. contactor B. internal overload C. relay D. external overload

A

An overload can be opened by _________________. A. heat or amperage B. pressure or heat C. amperage or pressure D. timer or heat

C

The contact surfaces of relays, contactors, and starters are made of _____________. A. magnesium B. steel C. silver D. iron

False

The purpose of the overload is to disconnect the motor from the circuit during the system off-cycle True or False

A

The recommended repair for a defective relay is to ______________ A. replace it B. send it to a repair shop C. repair it yourself D. bypass it

A

The two amperages that influence the choice for replacing a motor starter are _____________. A. rated-loaded amperage (RLA) and locked-rotor ampearage (LRA) B. rated-loaded amperage (RLA) and reverse-rotation ampearage (RRA) C. locked-rotor ampearage (LRA) and start-up amperage (SA) D. service factor amperage (SFA) and reverse-rotation ampearage (RRA)

C

The two types of relays are ____________. A. thermal and magnetic B. pilot duty and solder pot C. pilot duty and motor starting D. motor starting and solder pot

A

Two types of thermal overloads are _________________ A. solder pot and bimetal B. magnetic and bimetal C. internal and external D. mechanical and electrical

B

What is the difference between a contactor and a starter? A. A relay has overload protection built into, a starter does not B. A starter has overload protection built into, a relay does not C. A relay can be repaired, a starter cannot D. A relay is used to start large motors, a starter is used to start smaller motors

D

When rebuilding a contactor or starter, which of the following components can be changed? A. The contacts and springs only B. The coil and contacts only C. The contacts and coil only D. The contacts, coil, and springs

A

Which is not a typical operating voltage used for relays, contactors, and motor starters? A. 12 V B. 24 V C. 115 V D. 230 V

D

Which of the following is considered when the overload protection for a motor is designed? A. The rotation of the motor shaft B. The size of the motor capacitor C. The motor mount that is used D. The motor's service factor

B

Why should contactor contacts not be filed or sanded? A. The shavings or filings will cause increased electrical resistance B. The silver coating will be removed and cause more resistance in the contact surface C. The contactor would have to be disassembled and it is not recommended to do so D. It may cause the contactor coil to burn

C

___________________ motor protections is provided by thermally acuated snap-discs located on the compressor's exterior shell A. Inherent overload B. Internal overload C. External overload D. Circuit overload