Test 1030 Flashcards
The unit of opposition to electron flow is called ___________.
Resistance
Resistance is measured in ohms.
Of the three, which type of diagram is best suited to troubleshoot a circuit problem?
Schematic
Schematic diagrams provide a clear representation of the circuit’s components and their connections.
Which of the three is best suited to locate a component’s position?
Pictorial
Pictorial diagrams show the physical layout of components.
Circle the correct prefix value for ‘2500 watts’.
2.5 KW
2500 watts is equivalent to 2.5 kilowatts.
Power from the transformer to the fan relay ________.
G
The letter designation for the fan relay connection may vary based on the system.
Power from the transformer to the thermostat ________.
R
R typically indicates the wire to the thermostat.
Power from the thermostat to the heating circuit ________.
W
W is commonly used for the heating circuit connection.
Power from the thermostat to the cooling circuit ________.
Y
Y is often designated for the cooling circuit.
L1 voltage feed from the 240 voltage supply ______.
Black
Black is commonly used for L1 in 240V circuits.
L2 voltage feed from the 240 voltage supply ______.
Red
Red is typically used for L2 in 240V circuits.
120 voltage hot line ______.
Black
Black is usually the color for hot lines in 120V circuits.
120 voltage neutral ______.
White
White wires are standard for neutral connections.
120 voltage ground ______.
Green
Green wires are used for grounding in electrical systems.
A safety factor of ______ percent must be added to the measured current when sizing a wire.
25
A 25% safety factor is commonly recommended for wire sizing.
Where does the ohmmeter get power to read resistance between the probe leads?
Internal battery
Ohmmeters use an internal battery to supply power for resistance measurement.
What value remains the same in a parallel circuit?
Voltage
In a parallel circuit, the voltage across all components remains constant.
With 240 volts applied to a condensing unit, if the fan motor develops an open circuit, would the compressor lose its voltage?
No
The compressor would still receive voltage as it is in parallel with the fan motor.
Which relay has the larger wire size of the relays?
Start relay
Start relays typically require larger wire sizes due to higher current at startup.
A double breaker is used for how many volts?
240 volts
Double breakers are commonly used for 240V circuits.
Which way do we wrap the wires around screw terminals?
Clockwise
Wires should be wrapped clockwise to ensure a secure connection.
The small slot on the face of a 120 volt receptacle identifies what?
Hot connection
The small slot is typically for the hot wire.
The green screw on a receptacle or switch is used for attaching it to ground. True or false?
True
The green screw is designated for grounding connections.
What do we call a device used to convert potential energy into useful work?
Motor
Motors convert electrical energy into mechanical energy.
If the load is not connected in a 24 volt circuit and there is an open fuse, how many volts will read across the fuse?
0 volts
An open fuse will result in no voltage reading across it.
The smaller the wire gauge means the diameter of the wire is _____
Larger
A smaller gauge number indicates a thicker wire.
What value remains the same in a series circuit?
Current
In a series circuit, the current through all components is the same.
The third pin on the base of the 120 volt receptacle is connected to what?
Ground
The third pin is for grounding purposes.
What are the two voltages that are available in modern residential housing?
120 volts and 240 volts
These are the standard voltages supplied in residential settings.
