Deck 10: Contactors, Relays, and Overloads

Question 1

Contacts are made of silver and cadmium, which resist sticking.

Answer 1

True

Question 2

What is an internal compressor overload?

Answer 2

An internal compressor overload is a small device inserted into the motor windings.

Question 3

Contactors make or break a set of contacts that controls the voltage applied to some load in cooling systems.

Answer 3

True

Question 4

One of the most common types of line voltage overloads is a(n) _____________________ mounted between two contacts.

Question 5

A(n) ____________________ is an electric device that protects a load from a high ampere draw by breaking a set of contacts.

Question 6

The chemical composition of contacts is such that they operate at cool temperatures of up to ____________________% of their current-carrying capacity.

Question 7

The _________________________ overload breaks the power to a motor.

Question 8

The contacts of a contactor make a complete circuit when the contactor is ____________________, allowing voltage to flow to the controlled load.

Question 9

Contactors are rated by the ampere draw they can carry.

Question 10

Fuses cannot be used to protect wires and non-inductive loads, but they provide adequate protection for inductive loads.

Question 11

Name five devices used in the HVAC industry that can be controlled by a relay.

Question 12

Overloads can be divided into two basic groups. What are these?

Question 13

The contactor contacts must be in good condition to ensure that the proper voltage reaches the load.

Question 14

The diagnosis of a faulty contactor encompasses three sections of the contactor: the coil, the contacts, and the ____________________.

Question 15

A contactor is used to control an electric load in a control system.

Question 16

Coil characteristics depend on the type of wire but not the manner in which it is wound.

Question 17

The simplest form of overload protection is the ____________________.

Question 18

A load that is purely resistive in nature with no coils to cause induction is called a resistive or ____________________ load.

Question 19

Relays cannot be used to open and close a control circuit.

Question 20

Briefly describe the types of loads that a contactor can control.