IDA-101-Chapter 10 Contactors Relays and Overloads- Mr.Graham

Which of the following devices is commonly used to control major loads in heating, cooling, and refrigeration systems?

• Capacitors

• Contactors

• Limit switches

• Transistors

A contactor will contain which of the following parts?

• Armature

• Contact

• Coil

• Contactors contain all of these parts

What part of a contactor slides up and down within slots within the contactor’s frame?

• Armature

• Contacts

• Coil

• Mechanical linkage

What is the purpose of the coil on contactors?

• Produce a magnetic field to cause the armature to rotate

• Produce magnetism to attract the armature causing the contacts to close

• Produce electricity to power loads controlled by the contactor

• Produce magnetism used to start electric motors

Contactor coils are available for which of the following voltages?

• 24 volts

• 120 volts

• 208/240 volts

• Coils are available for all the voltages

The part of a contactor that completes the circuit to a load when the contactor is energized is the ___________.

• contacts

• coil

• frame

• arc chute

Which of the following parts, when closing, complete the circuit to the load controlled by the contactor when the coil is energized?

• Coil

• Mechanical linkage

• Contacts

• Armature

Which of the following electrical loads will have a constant amp draw the entire time it is operating?

• Compressor motor

• Electric resistance heater

• Pump motor

• Condenser fan motor

Contact points in a contactor are often made of .

• Silver-cadmium alloy
• Brass alloy

• Copper

• Nickel-aluminum alloy

Which of the following resistance reading would indicate a good contactor coil rated for 24 volts?

• Zero ohms

• Infinite ohms

• 15 ohms

• None of these are good