Heating (Electric Heat), 30.0

Front 1

The type of material used for resistance wire in electric heat is

Back 1

Nichrome.

Front 2

Portable or small space heaters with glowing coils transfer heat by

Back 2

Radiation.

Front 3

Base board heaters transfer heat by

Back 3

convection.

Front 4

A disadvantage of a central forced air electric furans is that. A. There is no zone control for individual rooms., B. A thermostat must be installed in each individual room, C. Only line voltage thermostat can be use, D. It is difficult to add air conditioning

Back 4

A : There is no zone control for individual room.

Front 5

Three common controls used in central electric heat applications are thermostat, contactors, (or relay) A. Capacitor B. sequencer C. Cool anticipator

Back 5

B : Sequencer

Front 6

The low voltage thermostat is used for central electric heat because it is compact, it is responsive, and A- it provides fuse protection B- It acts as a limit switch. C- it is safe

Back 6

C : it is safe.

Front 7

The heat anticipator setting is determined by A- Adding all the current draw in the 24-Volt circuit that passes through the thermostat control bulb and heat anticipator. B- Using the amperage of fan motor. C- Using the total of high- voltage amperage of the circuit.

Back 7

A : Adding all the current draw in the 24 Volt circuit that passes through the thermostat control bulb and heat anticipator.

Front 8

The sequencer uses _________ (high or low) voltage control power to start and stop the electric heaters.

Back 8

Low

Front 9

True or Falls: A package sequencer can start or stop only one stage of strip heat.

Back 9

False.

Front 10

Two type of wiring diagrams are the pictorial and_________.

Back 10

Schematic ( line or ladder)

Front 11

The limit switch shuts off the unit if: A- High temperature occurs. B- The furnace is unable to maintain the correct heat. C- The heat anticipator does not function properly. D- The cool anticipator does not function properly.

Back 11

A : High temperature occurs.

Front 12

The ________ wire from the transformer furnishes power to the thermostat. A-Red. B-Blue. C-Orange. D- Yellow.

Back 12

A : Red

Front 13

State the formula used for determining the cubic feet per minute (CFM) air flow across the furnace heating elements.

Back 13

CFM = Qs/1.08 x TD.

Front 14

Power consuming devices are wired in _________ (series or parallel).

Back 14

Parallel.

Front 15

Power passing devices are wired in ___________ (series or parallel).

Back 15

series.

Front 16

The resistance wire often used in an electric heating element is made of: A- Copper. B- stainless steel. C- Nickel chromium. D- magnesium.

Back 16

C : Nickel chromium

Front 17

Radiant heat is transferred by: A- Ultraviolet rays. B- Infrared rays. C- Ionization. D- Diffraction.

Back 17

B : Infrared rays.

Front 18

Most electric baseboard units are ________ heaters. A- Natural draft convection. B- Forced draft convection. C- Forced draft conduction. D- Radiant.

Back 18

A : Natural draft convection

Front 19

Central forced air electric furnaces frequently use _________ to start and stop multiple heating circuits. A: Capacitor. B: Sequencers. C: Limit control. D: Cool anticipators.

Back 19

B : Sequencers.

Front 20

A sequencer utilizes a __________ to initiate its operation. A: Bimetal heat motor. B: Bimetal snap disc. C: capacitor. D: Nichrome resistor.

Back 20

A : Bimetal heat motor.

Front 21

The component location in the thermostat that shuts off the electric furnace down prematurely so that the space will not be overheated is the. A: sequencer. B: Cool anticipator. C: Heat anticipator. D: Mercury bulb.

Back 21

C : Heat anticipator.

Front 22

The disadvantage in using a contactor to open and close the circuit to the electric heating element is the. A: Noise it makes. B: Low control voltage. C: heating element would all be started at the same time unless separate time delay relay were used. D: both A and C.

Back 22

D : A and C

Front 23

A limit switch or control is used to: A: Start the furnace if the thermostat malfunction. B: Insure that the fan stop when the furnace cool down. C: start the furnace prematurely on a cold day. D: Open the circuit to the heating elements if the furnace overheats.

Back 23

D : Open the circuit to the heating elements if the furnace overheats.

Front 24

Electric unit heaters are usually installed: A: Hanging from the ceiling. B: As baseboard heat. C: As forced air furnaces. D: For hot water systems.

Back 24

A : Hanging from the ceiling

Front 25

Electric ceiling panel heat: A: easily adapts to central air conditioning. B: Is radiant type heat. C: Uses circulating hot water. D: Can easily have humidify equipment added to the system.

Back 25

B : Is radiant type heat

Front 26

The _____________ thermostat is commonly used for forced air electric furnace installations. A: Low voltage. B: All voltage. C: No voltage. D: High voltage.

Back 26

A : Low voltage.

Front 27

The _____________ thermostat is commonly used for baseboard electric installations. A: Low voltage. B: All voltage. C: No voltage. D: High voltage.

Back 27

D : High voltage.

Front 28

The control voltage for the controls on a sequencer are typically: A: 24V. B: 208V. C: 460V. D: 12V.

Back 28

A : 24 V.

Front 29

An electric furnace is operating on 225 V and is drawing 83 amps. What heat capacity is this furnace putting out? A: 55,787 Btu/h. B. 33,467 Btu/h. C: 98,953 Btu/h. D: 63,738 BTU/h.

Back 29

D : 63,738 BTU/h.

Hint 29

83amp x 225 v = 18,675 watts x 3.413 BTU/Watts

Front 30

The kw rating of an electric of an electric heater is the ____________(temperature rating, power rating, voltage rating, or name of the power company)

Back 30

Power Rating

Front 31

The Btu rating is a rating of the _________ (time, wire size, basis for power company charges, or heating capacity)

Back 31

Heating capacity

Front 32

The factor for converting watts to BTU is ________

Back 32

BTU/h = Watts X 3.413.

Front 33

A kw is _______ (1000 watts, 1200 watts. Or 10000 watts)

Back 33

KW = 1000 watts

Front 34

The typical air temperature rise across an electric furnaces normally considered (high or low) compared to a gas furnace.

Back 34

Low

Front 35

The air temperature at the outlet grilles of an electric heating system is considered (hot or warm) compared to a gas furnace.

Back 35

warm

Front 36

The circulating fan motor normally runs on (high or low) speed in the heating mode

Back 36

Low

Front 37

What is the current rating of a 7.5 kw heater operating at 230 volts?

Back 37

32.61 Amps

Hint 37

I = P/E

Front 38

A 12 kw heater will put out _______Btu per hour.

Back 38

40,956Btu/h

Hint 38

Btu/h = watts x 3.413

Front 39

Most heat anticipators are _______ (fixed resistance or variable resistance)

Back 39

Variable resistance

Front 40

A heat anticipator that is set wrong may cause _______ (no heat, excessive temperature swings, or noise in the system)

Back 40

Excessive temperature swings

Front 41

If the service technician momentarily shorted across the sequencer heater coil, it would cause which of the following? (blown fuse, burned heat anticipator, the heat turned on, or the cooling turned on)

Back 41

Burned heat anticipator

Front 42

All heating thermostats have heat anticipator. (true or False)

Back 42

False.

Front 43

When system has several sequencers that would cause too much current draw through the heat anticipator, which of the following could be done to prevent the anticipator from burning up ? A Install a higher amperage rated thermostat. B Wire the sequencer so that all of the coils did not go through the anticipator. C Change to a package sequencer. D B or C

Back 43

D : B or C.

Front 44

The heat anticipator differs from the cooling anticipator (True or False)

Back 44

TRUE

Front 45

When the furnace is two stage, there are how many heat anticipator

Back 45

Two if two stage thermostat is used.

Front 46

The heat anticipator is located in which component? (Thermostat or sub base)

Back 46

Thermostat

Front 47

If the heat anticipator was burned so that it was in two parts, the symptoms would be which of the following? A : No heat B : Too much heat. C : The cooling would come on. D : The residence would overheat

Back 47

A : No heat

Front 48

Low voltage controls are used for which of the following reasons? A : Less Expensive. B : Easier to troubleshoot. C : More Reliable D : Safety

Back 48

A and D

Front 49

Low voltage wire has an insulation value for which of the following? A : 50 V B : 100 V C : 500 V D : 24 V

Back 49

A : 50 V

Front 50

Wire size determined by which of the following? A : Voltage. B : Amperage. C : Ohms. D : Watts.

Back 50

B : Amperage.

Front 51

The gage of wire that is normally used in residential low voltage control circuits is which of the following? A : No. 12 B : No. 18 C : No. 14 D : No. 22

Back 51

B : No. 18

Front 52

Low Voltage wire always has to be run in conduit. (True or False)

Back 52

False.

Front 53

The normal low voltage for control circuits is which of the following? A : 50 V B : 24 V C : 115 V D : 230 V

Back 53

B : 24 V