Thermostats

Question 1

True or False

A thermostat can control the temperature of a conditioned space or a process

Answer 1

true

Question 2

T or F

“Manual changeover” is the terminology applied to the movement of mercury in a sealed contact type thermostat

Answer 2

false

Question 3

________ __________ is the changing from the heating mode to cooling mode (and vice versa) by thermal means only

Answer 3

automatic changeover

Question 4

A ________ is an instrument which responds to changes of temperature and which directly or indirectly controls temperature

Answer 4

thermometer

Question 5

A bimetal is usually made up of _____ different materials

Answer 5

two

Question 6

A change in _______ temperature will affect a change in the ______

Answer 6

ambient, bimetal

Question 7

T or F

“Droop” or “thermal offset” does not affect the operating control point of a thermostat

Answer 7

false

Question 8

Two commonly used metals in the construction of bimetal temperature sensing elements are _____ and ______

Answer 8

brass and invar

Question 9

Most exposed type contacts being used today have a magnet added. The magnet provides the _____-____ action making it possible for the electrical contacts to open and close quickly and precisely

Answer 9

detent snap

Question 10

T or F

Anticipation is the addition of heat to thermostat contacts

Answer 10

True

Question 11

T or F

Heating cycle anticipators are energized during the heating “off” cycle

Answer 11

false

Question 12

T or F

Range is the difference between the thermostat min and max operating points

Answer 12

true

Question 13

The difference between cut-out and cut-in is referred to as the _________

Answer 13

differential

Question 14

BY adding artificial heat to the thermostat bimetal an increased rate of response by the thermostat is available through a reduced differential is referred to as _________

a) minimum interlock
b) differntial
c) anticipation
d) droop

Answer 14

c) anticipation

Question 15

The setting of the anticipator in the heating cycle must match the ______ rating

Answer 15

current

Question 16

T or F

All thermostats should be level

Answer 16

True

Question 17

T or F

The best thermostat location in a residential installation is eight feet above the floor

Answer 17

False

Question 18

Always use _______ wiring when installing a thermostat

Answer 18

coloured

Question 19

The most important step in installing a thermostat is ______

Answer 19

location

Question 20

The final thermostat should be free of _______ that might make the contacts _____

Answer 20

vibration, close

Question 21

Thermostat installation should be about ___ feet above the floor

Answer 21

5 feet

Question 22

T or F

Low voltage (24v) wiring should be thermostat cable or equivalent with single leads of 18awg coloured coded wire as the minimum size for runs under 50 Ft

Answer 22

True

Question 23

In a heating system, a thermostat bimetal exposed to a false source of _____ may cause an extended “on” cycle

Answer 23

cold

Question 24

A _____ ______ is a good tool to use to clean exposed contacts

Answer 24

match cover

Question 25

A differential that is too ______ may cause a system to short cycle

Answer 25

small

Question 26

When troubleshooting a thermostat for a condition where the system short cycles look for:

a) false source of heat or cold
b) check differential
c) system oversized
d) all of the above

Answer 26

d) all of the above

Question 27

If the system stays the “ON” cycle too long, check

a) system undersized
b) false source of heat or cold
c) incorrect anticipator setting
d) all of the above

Answer 27

d) all of the above