E.
If line 1 of a circuit had a potential of 120 V and line 2 was neutral, the potential voltage (difference) between them would be 0 V.
A. True
B. False
B. False
A control can be which of the following?
A. Electrical
B. Mechanical
C. Electrical and mechanical
D. Chemical
C. Electrical and mechanical
What is the amperage capacity of a 240-V/24-V control transformer with a 40 VA rating?
A. 16 V
B. 6 A
C. 1.66 V
D. 1.66 A
D. 1.66 A
The resistance wire used in electric heating elements is usually ____.
A. copper
B. nickel steel
C. nickel chromium
D. aluminum
C. nickel chromium
Which type of wiring diagram is most useful for understanding how components are physically arranged in a control box?
A. Schematic
B. Pictorial
C. Ladder
D. Line wiring
B. Pictorial
Non-power-consuming, or power-passing, devices are commonly referred to as ____________________.
A. controls
B. switches
C. regulators
D. sensors
B. switches
The line side of a switch is the ____.
A. side the load is connected to
B. neutral side of the circuit
C. side the power source is connected to
D. side with the white wire
C. side the power source is connected to
In a simple circuit including a light bulb, wire, switch, and power source, the light bulb is ______, and the switch is _______.
A. power-passing; power-consuming
B. power-passing; non-power-consuming
C. power-consuming; power-passing
D. non-power-consuming; power-passing
C. power-consuming; power-passing
In order to prevent a duct-mounted electric heater from being energized when the fan is not on, a(n) ____________________ should be used.
What is the danger of operating an electric heating system with a clogged filter in a forced-air system?
A. It may cause an electrical short in the system.
B. It will lead to excessive noise and vibration.
C. It can result in overheating of the heating elements.
D. It will cause the heater to turn off automatically.
C. It can result in overheating of the heating elements.
Devices that pass power are always safety devices.
A. True
B. False
B. False
How can the technician read very low currents in a control circuit using an analog clamp-on ammeter?
A. Wind the wire 10 times and then divide the reading by 10.
B. The procedure is the same for any current.
C. Multiply the meter reading by 10.
D. It is not possible to read very low currents with a clamp-on ammeter.
A. Wind the wire 10 times and then divide the reading by 10.
A 120-V/24-V control transformer has a VA rating of 20. The maximum amperage the transformer will put out is 0.8 amps.
A True
B False
A True
A set of contacts actuated by a bimetal strip with a low-voltage wire wrapped around it is called a _____.
A. contactor
B. jumper
C. relay
D. sequencer
D. sequencer
you lose all your money
The heating anticipator is normally wired in _________.
A. parallel to the compressor
B. parallel to the heating contacts
C. series with the heating contacts
D. series with the cooling anticipator
C. series with the heating contacts
The cooling anticipator in a thermostat is usually an adjustable type.
A. True
B. False
B. False
A 10-wrap amperage multiplier is used with a(n) ____.
A. voltmeter
B. clamp-on ammeter
C. ohmmeter
D. megger
B. clamp-on ammeter
_______are the controls used to provide time delay between stages of electric heat.
A. Contactors
B. Timers
C. Relays
D. Sequencers
D. Sequencers
A 10 Kw heating element, operating on rated 240 V, will generate ____ Btu/h.
A. 29,319
B. 31,062
C. 34,130
D. 35,875
C. 34,130
A(n) ____ is the easiest diagram to use to follow a circuit. This diagram normally can be studied briefly, and the circuit function should become obvious.
A. pictorial diagram
B. ladder diagram
C. layout
D. oblique drawing
B. ladder diagram
In order for a heating system to be energized, the _______.
A. manual heat switch must be open and the automatic switch closed
B. automatic heat switch must be open and the surrounding temperature cold
C. manual heat switch must be open and the surrounding temperature cold
D. manual and automatic heat switches must both be closed
D. manual and automatic heat switches must both be closed
An electrical diagram showing the approximate location of the components is called a(n) ____.
A. pictorial diagram
B. ladder diagram
C. layout
D. oblique drawing
A. pictorial diagram
If the number two contact on a package sequencer fails to close, the number three contact can still close.
A. True
B. False
A. True
Electric heating units provide almost instant heat. Therefore, anticipators are not needed in electric heat thermostats.
A True
B False
B False
If an air-conditioning system is calling for cooling and the compressor is running but the indoor (evaporator) fan is not running, which terminal on the thermostat will the technician most likely check first?
A. G
B. R
C. Y
D. W
A. G
The _____ is nothing more than a set of switches.
A. transformer
B. coil
C. motor
D. thermostat
D. thermostat
A pictorial wiring diagram _________, whereas a schematic wiring diagram _______.
A. illustrates the design intent of the engineer; shows the component locations
B. shows the component locations; shows the current paths to the components
C. is used for troubleshooting; is used for installation
D. is drawn for a layperson; has more detail for advanced technicians
B. shows the component locations; shows the current paths to the components
Any unit heater designed to have air forced across the element should not be operated without the ____ operating.
What is an advantage of electric hydronic boilers?
A. Cooling and humidification systems can be easily added.
B. They do not require any external fuel sources.
C. They are efficient at converting electrical energy into heat energy.
D. They are reliable and require very little maintenance.
C. They are efficient at converting electrical energy into heat energy.
The defrost limit switch is open when ____.
Which three components must operate when a residential air conditioning system is in the cooling mode?
Which characteristic of electric hydronic boilers makes them suitable for installations where a venting system is impractical?
A. They do not require combustion, so they have no need for a venting system.
B The combustion system is contained within the unit.
C. They use a solar-powered heating system to generate heat.
D. They are connected to an external heat source, which eliminates the need for venting.
A. They do not require combustion, so they have no need for a venting system.
In terms of efficiency, electric heat ________ compared to oil and gas.
A. uses less energy
B. loses less energy during transmission
C. is more expensive to install
D. is less expensive to operate after installation
B. loses less energy during transmission
For each watt of electrical power, _____ Btu/h are generated.
A. 1.08
B. 3.413
C. 4.3
D. 6
B. 3.413
The heat anticipator in a thermostat is usually an adjustable type.
A. True
B. False
A. True
In a residential air conditioning system, the outdoor fan and compressor are wired in parallel.
A. True
B. False
A. True
On a wiring diagram of a low-voltage thermostat, what does the symbol W likely indicate?
A. Heating power terminal
B. Heating sequencer
C. Cooling power terminal
D. Fan
A. Heating power terminal
Quartz and glass panel electric units are classified as ____.
How do the coils of portable space heaters transfer radiant heat?
A. Ultraviolet rays
B. Infrared rays
C. Ionization
D. Refraction
B. Infrared rays
Which action should the technician take first when troubleshooting the thermostat on a heating and cooling system?
A. Manually jump the circuits one at a time.
B. Manually jump all the circuits at once.
C. Turn the switch to FAN ON and see if the fan starts.
D. Use a multimeter to check the voltage to each circuit.
C. Turn the switch to FAN ON and see if the fan starts.
The cooling anticipator is normally wired in _________.
A. parallel to the compressor
B. parallel to the cooling contacts
C. series with the cooling contacts
D. series with the heating anticipator
B. parallel to the cooling contacts
If the fan of an electric furnace were to fail and the high-limit switch were stuck closed, the heating element would be cut off by the ____________________.
A. circuit breaker
B. fusible link
C interlock circuit
D. sequencer
B. fusible link
One potential safety hazard that all technicians should be aware of when working on an electric furnace is that there are many exposed electrical connections behind the inspection panels.
A True
B False
A True
Most electric furnaces have several heating elements that are activated in stages to _____.
A. reduce the overall energy consumption by activating elements only when needed
B. provide a more even distribution of heat across the room
C. reduce startup noise
D. avoid energizing a high-power load all at once
D. avoid energizing a high-power load all at once
The continuity through a heat relay is checked using a(n) ____.
A. ohmmeter
B. voltmeter
C. clamp-on ammeter
D. micron gauge
A. ohmmeter
While checking a simple series 115-V circuit containing a fuse, a switch, and a light bulb, the technician's voltmeter reads 115 V across the light bulb socket. The light bulb is not on. The technician correctly concludes that the ____________________ is defective.
A. fuse
B. switch
C. bulb
D. voltmeter
C. bulb
you lose all your money
How is the heat anticipator setting on a room thermostat determined?
A. It is set based on the room temperature.
B. It is determined by the total current draw in the 24-V heating control circuit.
C. It is automatically adjusted by the thermostat based on the heating load.
D. It is pre-set at the factory and cannot be changed.
B. It is determined by the total current draw in the 24-V heating control circuit.
What is the purpose of the legend of electrical symbols in a wiring diagram?
A. It provides a list of all possible components in the diagram.
B. It helps technicians understand the functions of the components.
C. It clarifies the standard symbols used, ensuring accurate interpretation.
D. It illustrates the specific location of each component.
C. It clarifies the standard symbols used, ensuring accurate interpretation.