Deck 12: Thermostats Pressure Switches and Other Electric Control Devices

Question 1

In a remote bulb thermostat, the pressure exerted by the diaphragm on the mechanical linkage will open and close a set of ____________________.

Answer 1

contacts

Question 2

The transformer for a residential unit is used to convert line voltage to 24 volts.

Answer 2

True

Question 3

Transformers are 100% efficient.

Answer 3

True

Question 4

What are the two windings associated with a transformer?

Question 5

____________________ are stationary inductive devices that transfer electric energy from one circuit to another by induction.

Question 6

Some commercial and industrial high-voltage equipment uses transformers that drop the line voltage to 240 or 120 volts.

Question 7

Most residential and small commercial installations use a 12-volt control system.

Question 8

The temperature in any structure, regardless of its age, location, or design, can be maintained at comfortable levels with a(n) ____________________.

Question 9

In a remote bulb thermostat, as the temperature of the ____________________ changes, as will the pressure exerted on the diaphragm.

Question 10

The transformer in a heating or cooling system provides the low-voltage power source for the control circuit.

Question 11

A heating thermostat closes on a(n) ____________________ in temperature.

Question 12

What is the difference between a step-down transformer and a step-up transformer?

Question 13

The ____________________ thermostat is used on control systems with a 24-volt supply.

Question 14

The difference between a line voltage and a low-voltage thermostat is in the size of the bimetal element.

Question 15

The ____________________ element of a thermostat is the part that moves when a change in temperature is sensed.

Question 16

What is the basic function of a thermostat?

Question 17

The bimetal thermostat derives its name from the fact that it uses three similar metals.

Question 18

What are two methods in common use that enable thermostats to be snap-acting?

Question 19

The ____________________ thermostat is commonly used to control the temperature of any medium, whether liquid or vapor, in many applications.

Question 20

Transformers are rated by their primary voltage, secondary voltage, and volt-amperes (VA).