ACR Unit 19 Review (CRF) QUIZ Mr. Graham pt.1

A common practice in condensing units is to use a contactor with only one set of contacts opening only one side of the power to the unit. This is to ____.

• reduce the cost of the contactor

• provide off-cycle heat to the compressor

• make it easier to wire the unit

• teach the service technician not to put hands in the unit with the power on

Beside maintaining pressure on the contacts for current carrying capacity, the pressure springs have a second important function. This is to ____.

• help obtain equal contacts against the stationary contacts

• increase the power required to close the contacts

• slow down the pull of the armature into place to reduce the noise

• keep the contacts in line

When a contactor's coil is energized, how much resistance should be measured between terminal "L1" and terminal "T1"?

• infinite

• 50-3000 ohms

• 5000-6000 ohms

• zero ohms

Technician “A” says that if you take a voltage reading from terminal "L1" to terminal "T1" on a contactor whose coil is energized, you should read zero volts. Technician “B” says that contactors can only have normally open contacts. Which of the following statements is correct?

• Technician "A" is correct. Technician "B" is correct.

• Technician "A" is incorrect. Technician "B" is incorrect.

• Technician "A" is correct. Technician "B" is incorrect.

• Technician "A" is incorrect. Technician "B" is correct.

An inherent motor protector is a ____.

• line fuse

• circuit breaker

• thermally activated device in the motor winding

• motor starter overload

The service factor of an electric motor is determined by ____.

• the required wire size supplying power to the motor

• National Electrical Code

• motor's reserve capacity

• the required wire size supplying power to the motor

Standards for motor overload protection are set by the ____.

• American National Standards Institute

• Environmental Protection Agency

• National Electrical Code

• Environmental Protection Agency

A solder pot is part of a ____.

• plumber's tool kit

• time-delay fuse

• resettable circuit breaker

• one-time fuse

Which of the following overload devices is not affected by ambient temperature?

• magnetic

• bimetal

• solder pot

• time-delay fuse

The locked rotor amperage, LRA, of a motor is typically five times higher than the full load amperage, FLA, of the motor and can be as high as seven times the FLA.

• true

• false