Electrical wiring and Diagrams Flashcards
A circuit that only has one path for current to flow, it is defined as a/an;
Series circuit
In a series circuit, the total opposition to the current flow (RT) is;
Equal to the sum of each of the resistances
The sum of all voltages in a closed circuit is zero describes;
Kirchhoff’s Law
A circuit that has more than one path for the current to flow can be described as a/an;
Parallel circuit
In which section of the CEC are Class 1 and 2 circuits defined?
Section 16
What is the maximum VA rating for Class 1 extra low voltage power circuits?
1000 VA
The maximum power output of a Class 2 circuit supply must be restricted to
100 VA
The voltage of Class 2 circuit must be 150 V or less.
T or F
true
What is the maximum allowable current that a 24 V Class 2 circuit?
4.16 A
According the CEC, a gas-fired appliance can be part of a combined branch circuit.
T or F
False
If a transformer has a secondary voltage of less than 50 V and the primary voltage is 150 volts-to-ground or less, is grounding required?
No
What is the minimum distance required between a switch and a gas meter or relief device?
3 feet
A disconnect must be placed within _____________ and within sight of the rooftop mechanical equipment it serves.
10 feet
You can use ELC for wiring a 24 V thermostat circuit
False
As a rule, where should controlling devices which sense changes in conditions, be shown on a schematic diagram?
Left Side
Devices should be shown in the following manner on a schematic diagram with the exception of;
Power on
Which diagram would show the relative physical location of components?
Wiring
Which diagram shows controls using scale drawings or pictures?
Pictorial
What is another name for a connection diagram?
Line
With direct reference to wiring diagrams, where would a technician find information regarding the symbols used for factory and field wiring, as well as the colour and voltage of the wire?
Legend
Which portion the manufacturer’s literature would provide a very simple step by step walk through of how a device is supposed to operate?
Flow chart
Which drawing allows you to analyze the power flow of an electrical circuit and shows you how a circuit works and how its components are coordinated to work with each other?
Ladder
There are standards for wiring symbols which each manufacturer must adhere to for the sake of uniformity across the industry.
T or F
False
In solid state devices, relays are replaced by;
Triacs or Transistors
What force is utilized to open a diaphragm gas valve?
Working gas pressure
A solenoid gas valve has the ability to modulate gas flow.
T or F
False
What gas appliance typically utilizes the “Rod and Tube” control principle?
Residential hot water tank
An aquastat is considered;
A normally closed control & An operating control
Solid-state controls are quicker response time, less space and less servicing (no moving parts).
T or F
True
From the list, which of the items would be considered false with regards to solid-state devices?
no moving part
are able to withstand power surges
require less maintenance
Take up less space
Are able to withstand power surges
What term describes a device that converts AC current to DC current?
Rectifier
Thermistors are sensing devices that react to;
Temperature
If an RTD (resistance temperature detector) has a positive temperature coefficient;
An increase in temperature results in an increase in resistance
What are the two most important tools when troubleshooting?
Wiring diagram & Multi-meter
When you are troubleshooting electronic systems, what component should be your initial primary focus?
Solid state control board
At no time should you try to troubleshoot the individual components on the board or module.
T or F
True
With an electronic control board readout, you should be able to troubleshoot problems by using;
Wiring diagrams & Manufacturer’s troubleshooting charts
Flame Spectrum could be defined as:
The band of electromagnetic radiation emitted from a flame
The total infrared radiation produced from a burner flame would be about:
90%
Ultraviolet radiation is emitted from the _______________ of the flame.
1st third
The only flame detector that is affected by ignition interference is:
Flame rod
The pilot turndown test is required on which the following flame detectors?
UV
IR
Visible
Flame rod
All of the above
all of the above
Safe operation of the flame safeguard detection system is the responsibility of:
The person activating the appliance
schematic diagram is also known as a _____________________.
Ladder diagram
What is the purpose of ladder and schematic diagrams?
To show how circuits work and the function of their components
How are components represented on connection diagrams?
Simple pictorials
The sequence of operation of a circuit can be determined from what kind of drawing?
Schematic diagram
In which operating position will the switches and other devices in a circuit be shown on a wiring diagram drawn in the “at rest” state?
Normal position
A__________ diagram can be divided into two distinct portions. The top is the power portion and the bottom is the control portion
Ladder diagram
A schematic diagram shows the electrical relationship between components in a circuit, while a wiring diagram shows how components are actually wired.
T or F
True
On a ladder diagram the source/hot line is drawn on the right.
T or F
false
How is the field wiring identified on a wiring schematic?
Dotted lines
The left-hand side of the ladder diagram represents the incoming voltage.
T or F
true
Which electrical drawing would be considered a map of an electrical circuit?
Wiring diagram
Which electrical drawing is best used to determine how current flows through the various parts of the circuit?
Schematic diagram
