Gas - Worksheets Flashcards
An atom has one of its electrons removed and becomes a charged particle known as an “ion”. What is the charge on this ion?
Positive.
What determines whether a material is going to be a good conductor or a good insulator?
Number of valence electrons.
Magnetism caused by the movement of electrons is the definition of?
State 2 places where gasfitters would use the defintion of the description above.
Electromagnetism.
Gas valves and safety valves.
Of the six sources of electricity which are the two most used in the gas fitting industry? Of those two are they sources of direct current or alternating current?
Heat - Direct current.
Magnetism - Alternating current.
Define direct current and alternating current.
Direct current - One direction only.
Alternating current - Both directions.
An abnormal connection between two nodes of an electric circuit intended to be at different voltages is the defintion of?
Short circuit.
What is the order of components in an electrical circuit?
A. Source Switch Load.
B. Switch Load Source.
C. Load Source Switch.
D. Conductor Load Source.
A. Source Switch Load.
Where are the three particles present in an atom located in the atom?
Electron: Revolves around the nucleus.
Neutron: Located in the center of the nucleus.
Proton[][]: Located in the center of the nucleus.
What is an ion?
A negatively or positively charged atom.
What is the “law of electrical charges”?
“Like charges repel and unlike charges attract.”
What is the force that keeps electrons in their orbit and what is the force that is trying to move the electrons out of their orbit?
“Attraction of the nucleus” keeps the electrons in their orbit.
“Centrifugal force” tries to move the electrons out of their orbit.
Why is it important to understand valence shells when dealing with electricity?
The electrons in the valence shell are the electrons that are set free most easily.
The flow of tiny particles (electrons) is the definition of?
Electrical current.
A force created by magnets is the definition of?
Magnetism.
Magnetism caused by the movement of electrons is the defintion of?
Electromagnetism.
What are some uses of electromagnetism?
CD Players.
Clocks[][][][]]
Cranes[][][][]]
Generators.
Motors[][][][]]
Testers[][][][]]
Washing Machines.
A scenario where there is a complete path for electricity to flow is the definition of?
Electric circuit.
What components are essential in an electric circuit?
Source - Switch - Load.
Basic measure of a quantity of electrical charge is the definition of?
Coloumb.
What is voltage?
How do you measure voltage?
Electrical pressure.
Multimeter/Voltmeter.
What is current?
How do you measure current?
Electrical Flow.
Measured in amps or amperes.
What is ohm’s?
How do you measure ohm’s?
Electrical resistance.
Measured in ohm’s[][]
What is ohm’s law for power?
P = E x I.
All loads wired to each other.
One goes out, all go out[][][][][]
Operating controls should be wired this way.
Voltage decreases as loads are added to the circuit.
Current remains constant[][][][][][][][][][][][][][][][][][][][][][][][][][][]
Series circuit.
All loads are wired independantely of each other.
One goes out, other loads remain energized[][][][]]
Fan or pump should be wired in this manner[][][][][]
Ampacity decreases as loads are added to the circuit.
Voltage remains constant[][][][][][][][][][][][][][][][][][][][][][][][][][][]
Parallel circuit.
What is polarity when dealing with electric circuits?
Positive/Negative.
What is the waveform generated by an AC current?
Sine wave.
What is the waveform generated by a DC current?
Straight line.
What does the term phasing refer to when dealing with electricity?
Getting the electricity to go in a certain direction to start.
What’s the frequency of an AC generator here in North America?
60 hertz.
Which kills you, current or voltage?
Current.
How many millvolts does a thermocouple produce when new?
How about a thermopile?[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
When would you use a thermopile instead of a thermocouple[]?
Thermocouple - 30mV.
Thermopile - 250mV-750mV.
Thermopile produces enough voltage to power a control circuit and safety circuit.
What is the difference between an operating aquastat and a high limit aquastat?
If you were wiring these in a system how would they be wired in relation to each other?
Operating Aquastat (160°F - 180°F).
High Limit Aquastat (200°F)[][][][][][]]
They would be wired in series[][][][]]
Operating steampressure switches on steamboilers.
High limit just adjusted to a higher pressure setting[]
Is the definition of?[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
Pressuretrol / High limit pressuretrol.
Keeps the room temperature close to set point is the definition of?
What amperage is this device set to? How do you set that amperage?
Heat anticipator.
Set to the amperage of the gas valve. Set with a knob on the front of the thermostat.
What type of fan switch is on a furnace?
Explain how it works. What are the “FAN ON” and “FAN OFF” setpoints?
Why is there a difference[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]?
Reverse Acting Tempurature Actuated Switch.
Closes on a rise in heat. Fan On - 115°F / Fan Off - 90/95°F.
There is a difference so the fan doesn’t constantly cycle on and off.
You’ve been asked to service a furnace. The first thing you notice is that the burner is on and running smoothly. You also notice that the fan seems to come on and then go off quite frequently. What could be the issue?
Fan set at too high of a speed[][][][][][][][][]]
Fan switch set points could be too close.
How would you go about testing the high limit setting on a furnace?
Disable the fan (Heat goes up - Find out if high limit setting is working).
You are servicing a boiler system. The system calls for heat and the boiler startup routine begins. It goes through the motions but the burner does not fire. This occures 3 times and then the appliance goes into lockup mode. What is your first course of action?
Check Gas (Source).
Check Power (Source).