IDA-201 Unit 19

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 ____.

• provide off-cycle heat to the compressor
• reduce the cost of the contactor
• 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
• keep the contacts in line
• slow down the pull of the armature into place to reduce the noise
• increase the power required to close the contacts

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

• zero ohms
• 50-3000 ohms
• 5000-6000 ohms
• infinite

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

An inherent motor protector is a ____.

• thermally activated device in the motor winding
• circuit breaker
• motor starter overload
• line fuse

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

• motor's reserve capacity
• National Electrical Code
• National Electrical Manufacturers Association code
• the required wire size supplying power to the motor

Standards for motor overload protection are set by the ____.

• National Electrical Code
• United States Department of Transportation
• Environmental Protection Agency
• American National Standards Institute

A solder pot is part of a ____.

• resettable circuit breaker
• one-time fuse
• time-delay fuse
• plumber's tool kit

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

• magnetic
• solder pot
• bimetal
• 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