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117 Cards in this Set
- Front
- Back
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Battery or power source |
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Thermocouple |
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Thermopile |
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Transformer or iron core |
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Line voltage Factory wire |
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Line voltage field wire |
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Low voltage Factory wire |
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Low voltage field wire |
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Middle |
Circuit breaker |
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Conductors crossed |
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Fuse |
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Earth ground |
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Chassis ground |
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Capacitor |
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Fusible link |
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Middle one |
Interlock |
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Brake on temperature rise |
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Make on temperature rise |
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Make on pressure drop |
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Make on pressure rise |
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Brake on level rise |
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Normally closed contacts |
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Normally open contacts |
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Electromagnet |
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Solenoid coil |
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Resistor |
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Coil |
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Pilot lamp |
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Make on Flow increase |
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Make own flow decrease |
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Brake on level drop |
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How can a series circuit be identified |
The components are wired into a single current pathway |
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How is the resistance of a series circuit calculated |
The resistance of all the components are added together |
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What is the distinguishing characteristics of a parallel circuit |
The components of the circuit are wired separately to the power source |
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How is the resistance of a parallel circuit calculated |
The reciprocal resistance of all the components is added together |
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Which type of wiring diagram shows scale representation of the controls |
Pictorial diagram |
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Which type of diagram shows the appliance operates |
Ladder diagram |
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How are the controls on wire diagram shown |
Appliance in standby |
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Which type of diagram is best suited to show which wire connects to a particular control |
Connections diagram |
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Which wiring diagram is used to determine the colour code of a wire |
Connections diagram |
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Based on the diagram which circuits are energized |
The blower motor only |
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What would the voltage reading be if a voltmeter were connected to the gas valve terminals |
0 volts |
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Kirchhoff's amperage law states |
The total amperage draw of a parallel circuit will be the sum of the amperage draws through each leg of the circuit |
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How are switches wired |
Switches are wired in series with the gas valve |
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How are power consumers wired |
In parallel |
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What does a heat anticipator do |
Prevents temperature overshoot |
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How does a diagram gas valve open |
Gas pressure acting on the diaphragm the valve is slow in responding to the call for the thermostat operating control |
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How does a solenoid gas valve open |
An iron core creates a magnetic field solenoid gas valves reacting immediately fast-acting |
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How is the heat anticipator connected to the Circuit inside a thermostat |
In series with the thermostat contacts |
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How is a blower door interlock wired into the power source |
In series / parallel |
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If a high temperature limit control is not wired into the 24 volt circuit of an appliance where would it be found |
In the 120 Step Down Transformer circuit |
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Kirchhoff's voltage law states |
The sum of all voltage in a closed circuit is zero |
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Class 1 circuit limitations |
Class one extra low voltage power circuits are restricted to a maximum of 30 V and a maximum power level of 1000 VA |
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A maximum of a 5A rated over current device can be used for a |
Number 18 AWG |
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Class 2 circuit limitations |
The voltage of the circuit must be 150 V or less The maximum power output of the circuit Supply must be restricted to a 100 VA |
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Does a gas-fired appliance require to be on its own branch circuit |
Yes |
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True or false a maximum of a 5a overcurrent device can be used for a number 18 AWG conductor |
True |
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All electrical circuits need three components in order to work these are |
A power source a load and a conductor |
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Get familiar with this diagram it's on the test |
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Minimum distance between a gas metre and a switch |
900 mm AKA 3 ft |
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A disconnect for rooftop unit must be within |
3 m a k a 10 ft and within sight of the rooftop unit |
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What law states the applied voltage must equal the sum of the voltage drops |
Kirchhoff's voltage law |
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Which circuit would have a total resistance higher than any individual resistance |
Series circuit |
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Which circuit would have a total resistance lower than any individual resistance |
Parallel circuit |
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In which circuit would the component wired in series control the components wired in parallel |
Series / parallel circuit |
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In which circuit would the components wired in series act independently of the components wired in parallel |
Series and parallel circuit |
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What is the purpose of a direct fired make-up air unit |
To provide a high volume of air exchanged in a building |
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Ohm's law states that |
It takes 1 volt to push 1 amp through 1 ohm of resistance |
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Current is |
The amount of electrons flowing through an electrical circuit and is measured in amps |
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Resistance is |
The opposition to the flow of electrons in the electrical circuit measured in ohms |
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A material that can transmit the free flow of electrons is considered to be |
A conductor |
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The rate at which electrons do work is referred to as |
Electrical power and is measured in watts |
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Ac power |
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DC power |
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R is |
Power |
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W is |
Heating |
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G is |
Fan |
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Y is |
Cooling |
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C is |
Common |
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How does a humidifier operate |
Interlocked with the blower motor |
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How do you set the Heat anticipator |
Current draw of the circuit or ampdrawn on the valve |
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On a forced air furnace what must the high limit be set to |
250 degrees Fahrenheit |
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When using millivolts what kind of gas valve would you have to use |
Diaphragm gas valve |
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How is electromotive force measured |
Volts |
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How is resistance measured |
Ohms |
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How is electrical power measured |
Watts |
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Why are parallel circuits used in the heating industry |
The supply seem volts to the loads |
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How is a voltmeter connected to a circuit |
Parallel power on |
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How is the ammeter connected to a circuit |
Series power on |
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How is the ohmmeter connected to a circuit |
Parallel power off |
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What is the maximum height limit setting for a forced air conversion furnace |
250 degrees Fahrenheit |
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What load is wired in series with the timed fan switch |
Blower motor |
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What will the high limit switch directly deactivate when it is open |
Transformer |
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Which component directly controls the timed fan switch |
Thermostat |
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What does the ignition module activate first when energized |
Ignition and pilot valve |
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What does the ignition module activate first when energized |
Ignition and pilot valve |
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What will a poor ground on the ignition module case |
No main flame |
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The amperage in a series circuit will be |
The same regardless of where it was taken in the circuit |
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T h stands for |
Thermostat |
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T r stands for |
Transformer |
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Most ladder diagrams are read |
From left to right the left side of the diagram is hot |
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18 gauge wire can go up to what amp |
5 amp |
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16 gauge wire can go up to what amp |
10 amp |
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Switches and other electrical devices must be how far are we from a gas metre or relief device |
3 feet |
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What is a contactor |
Works the same way as a relay but is larger it can handle a larger current rating |
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The low limit device |
Is normally closed contacts activated by a temperature sensing device low limit will open if the supply air temperature drops to below 40 degrees Fahrenheit |
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A damper motor |
Electrically driven motor used to open closed or modulate a damper blade or set damper |
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End switch |
Used to verify that a mechanical action has been completed and it is safe for another action to take place by closing or opening an electrical circuit |
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Limits and safety switches are |
Normally closed switches that open the circuit to disrupt the flow of gas to the burner of a appliance |
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What does a solid-state rectifier do |
Changes the current from AC to DC and can be used to regulate the speed of the blower motor |
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Flame rectification what's the ratio |
4 ((ground) 1(rod) |
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What are the two types of material hot surface ignitors can be made from |
Silicon nitride Silicon carbide |
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What voltage can spark igniters come in |
24v 120v 12v |
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What is the recommended spark gap |
1/8" |
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Flame impingement on thermoelectric device |
3/8"-1/2" |
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Direct burner ignition spark or hot surface ignitor response time is up to 400,000 BTUs |
90 seconds |
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Approximately how much of the flame Rod tip is enveloped in the outer cone of the burner |
1 inch |
