Embedded Files
Analysis Phase
Learning Objectives
At end of the lesson, the student should be able to:
a. Plan and prepare for termination/connection of electrical wiring/ electronics circuits
b. Terminate/connect electrical wiring/electronics circuits
c. Test termination/connections of electrical wiring electronics circuits
Design Phase
Subject Matter
Topic: Terminate and Connect Electrical Wiring and Electronics Circuits
Materials:
Mode of Delivery: Online class using Google Meet
Time Allotment: 2days/ 180 minutes (one week)
High Technology: Laptop, Electrical components, Powerpoint presentation, online teaching platforms (Google form)
Development Phase
A. Pre-Activity
Prayer
Checking of Attendance
Review
Setting of Standards
Activity 1: Identification
Link is provided below
Activity 2: Multiple Choice
Answer the following questions.
Implementation Phase
B. Lesson proper
Activity 3: Exercise
Instructions:
After the discussion, the students will answer the quiz
The link is provided below.
USE OF HAND TOOLS AND TEST INSTRUMENTS/EQUIPMENT
There is a tool for every purpose, and each tool is especially designed for a particular purpose. Using another tool as a substitute for the correct tool is inviting injury.
Lay tools to be used neatly on the bench top. Place the cutting edge away from you. Do not let the tools rub against each other. Make sure that sharp tools do not extend over the edges of the bench.
Place heavy tools at the center of the bench where they will not be pushed off and fall. Place tools with cutting edges, such as chisels, saws, and dividers, so that no one will be injured.
Keep the sharp edge or point of a tool down when you are carrying it. Do not swing your arm or raise it above your hand. Do not carry sharp tools in your pocket. Carry only a few tools at a time
Hold the tool in a correct way when you are using it. Be careful when you use your hand, finger (or thumb) to keep the tool in the right place when you are starting to cut something. Use the tool in the correct way and for the correct purpose.
Keep tools properly sharpened. Hand tools such as wood chisels, saws, knives, planes etc. should be used carefully. If these tools are dull, they can slip.
Make certain that all files have handles. See that handles of planes, hammers and mallets are tight.
ELECTRICAL SAFETY
Electricity is a wonderful utility, but can be dangerous if not approached carefully. There are three basic hazards that cause injury or death – shock, arc-flash, and arc-blast.
SHOCK
An electrical shock is a current that passes through the human body. Any electrical current flows through the path of least resistance towards ground; if an external voltage contacts a human body, e.g. by touching a live wire with the hand, the voltage will try to find a ground, and a current will develop that flows through the body’s nervous system or vascular system, and exit through the closest part of the body to ground (e.g., the other hand which may be touching a metal pipe.)
ARC-FLASH
An arc-flash is an extremely high temperature conductive mixture of plasma and gases, which causes very serious burns when it comes into contact with the body, and can ignite flammable clothing.
ARC-BLAST
Arc-blast is a pressure wave resulting from arcing, which can carry molten metal fragments and plasma gasses at very high speeds and distances.
Voltage
The measure of the push on each electron which makes the electron move. The term potential difference and voltage are often used interchangeably to mean the “push”, thus, you may see the term electromotive force (EMF) or just the word potential to describe the electron push in certain instances.
Current ‐ The flow of electrons in the circuit.
Resistance ‐ The opposition to current flow.
Power ‐ The rate of doing work.
Resistor ‐ A device designed intentionally to have a definite amount of resistance
Capacitor ‐ A device that stores electrical energy.
Termination - The point where a line, channel or circuit ends.
OHS ‐ Occupational Health and Safety
DIRECT CURRENT AND ALTERNATING CURRENT
Direct Current or DC is the first type of current because it was easy to produce. This type of current always flows in one direction. One of the disadvantages of using DC is the excessive voltage drop and power loss in the power lines in a long distance transmission. Batteries are common sources of direct current.
Alternating Current or AC is the solution to the problem of DC. AC allows the flow of current in two directions. Today, it is possible to step‐up electricity, a power station, transmit it to any distant place and step it down to for consumption. A transformer is the device used for stepping‐up or stepping‐down AC voltage. Common sources of AC are found in our AC outlet (Typically, 220 volts, in the Philippines).
BASIC ELECTRICAL AND ELECTRONIC DEVICES
A Simple circuit contains the minimum things needed to have a functioning electric circuit. A simple circuit requires the following:
AC/DC source
Equipment that will operate on either an AC or DC power source
Battery – A dc voltage source containing two or more cells that convert chemical energy to electrical energy.
Cell‐ Single unit used to convert chemical energy into a DC electrical voltage.
FUSE - is a safety device used to protect an electrical circuit from the effect of excessive current. Its essential component is usually a strip of metal that will melt at a given temperature.
WIRE AND CABLE - A wire is a single slender rod or filament of drawn metal. This definition restricts the term to what would ordinarily be understood as solid wire. The word “slender” is used because the length of a wire is usually large when compared to its diameter.
SWITCHES AND IT'S FUNCTION - Switch is a device used to break an electric current or transfer it to another conductor. Switches are commonly used to open or close a circuit. Closed is the ON position, while open is OFF position.
SWITCH FUNCTION
When the switch is closed, the electron finds an interrupted path in the circuit.
Open is the OFF position of the switch, while closed is the ON position.
When the switch is opened, the current delivered by the power supply is normally insufficient to jump the switch gap in the form of an arc and the electron flow in the circuit is blocked.
Load
a source drives a load. Whatever component or piece of equipment is connected to a source and draws current from a source is a load on that source.
CLASSIFICATION OF ELECTRONIC COMPONENT
A. Passive devices ‐
A Passive Device is one that contributes no power gain (amplification) to a circuit or system. It has no control action and does not require any input other than a signal to perform its function. In other words, "A component with no brains!"
Resistor - This is the most common component in electronics. It is used mainly to control current and voltage within the circuit.
Capacitor - Capacitors, or "caps", vary in size and shape ‐ from a small surface mount model up to a huge electric motor cap the size of paint can.
Inductor - It is charged with a magnetic field and when that field collapses it produces current in the opposite direction. Inductors are used in Alternating Current circuits to oppose changes in the existing current.
B. Active Devices
Diodes - are basically a one‐way valve for electrical current. They let it flow in one direction (from positive to negative) and not in the other direction.
LEDs - are simply diodes that emit light of one form or another. They are used as indicator devices.
The transistor - is possibly the most important invention of this decade.
Integrated Circuits, or ICs, - are complex circuits inside one simple package. Silicon and metals are used to simulate resistors, capacitors, transistors, etc. It is a space saving miracle.
ELECTRONIC SCHEMATIC SYMBOLS
Wire - To pass current very easily from one part of a circuit to another.
Wires joined - A 'blob' should be drawn where wires are connected (joined), but it is sometimes omitted. Wires connected at 'crossroads' should be staggered slightly to form two T‐ junctions, as shown on the right.
Wires not joined - In complex diagrams it is often necessary to draw wires crossing even though they are not connected.
Power Supplies/Source
Cell - Supplies electrical energy. The larger terminal (on the left) is positive (+). A single cell is often called a battery, but strictly a battery is two or more cells joined together.
Battery - Supplies electrical energy. A battery is more than one cell. The larger terminal (on the left) is positive (+).
Dc supply - Supplies electrical energy. DC = Direct Current, always flowing in one direction.
Ac supply - Supplies electrical energy. AC = Alternating Current, continually changing direction.
Fuse - A safety device which will 'blow' (melt) if the current flowing through it exceeds a specified value.
Transformer - Two coils of wire linked by an iron core. Transformers are used to step up (increase) and step down (decrease) AC voltages
Earth (ground) - A connection to earth. For many electronic circuits this is the 0V (zero volts) of the power supply, but for mains electricity and some radio circuits it really means the earth. It is also known as ground.
Output Devices/Loads: Lamps, Heater, Motor
LAMP (LIGHTING) - A transducer which converts electrical energy to light. This symbol is used for a lamp providing illumination, for example a car headlamp or torch bulb.
Lamp (Inductor) - A transducer which converts electrical energy to light. This symbol is used for a lamp which is an indicator, for example a warning light on a car dashboard.
Heater - A transducer which converts electrical energy to heat.
Motor - A transducer which converts electrical energy to kinetic energy (motion).
Bell - A transducer which converts electrical energy to sound.
Buzzer - A transducer which converts electrical energy to sound.
Inductor (coil, solenoid) - A coil of wire which creates a magnetic field when current passes through it. It may have an iron core inside the coil.
SWITCHES
Push Switch (push‐to‐ make) - A push switch allows current to flow only when the button is pressed. This is the switch used to operate a doorbell.
Push‐to‐Break Switch - This type of push switch is normally closed (on); it is open (off) only when the button is pressed.
On‐Off Switch (SPST) - SPST = Single Pole, Single Throw. An on‐off switch allows current to flow only when it is in the closed (on) position.
2‐way Switch (SPDT) - SPDT = Single Pole, Double Throw. A 2‐way changeover switch directs the flow of current to one of two routes according to its position.
Dual On‐Off Switch (DPST) - DPST = Double Pole, Single Throw. A dual on‐off switch which is often used to switch mains electricity because it can isolate both the live and neutral connections.
A simple circuit contains the minimum things needed to have a functioning electric circuit
Source ‐ a device used to supply AC or DC voltage
Consuming ‐ any device that consumes voltage, whatever component or piece of equipment that is connected to a source and draws current from a source is a load on that source.
Controlling ‐ any device having two states, on (closed) or off (open). Ideally having zero impedance when closed and infinite impedance when open.
Protecting ‐ a component used to open the circuit when current exceeds a predetermined maximum value.
Connecting ‐ a material that conducts electric current very well and used to connect a complete path for current.
ELECTRICAL WIRING
Wire sizing - The proper wire size is critical to any electrical wire installation. Wire sizing indicates the diameter of the metal conductor of the wire and is based on the American Wire Gauge (AWG) system
Non Mettalic (NM) Sheathed Cable - Most interior wiring is done with non-metallic, or NM, cable—also known by the popular brand name Romex. NM cable is made of three or more wires wrapped inside a flexible plastic jacket, or sheathing.
Electrical Wire Color Coding - Color coding is used both on the outer sheathing of bundled electrical cables and on the individual conduction wires within cables or inside the conduit.
Electrical Wiring Label - Electrical wires and cables have markings stamped or printed on their insulation or outer sheathing.
Direct-Burial Cable - Standard electrical cable is designed to be run indoors, where it stays dry and is protected by wall, ceiling, or floor structures.
Electrical Wire Stripping - Stripping electrical wire involves removing the plastic insulation surrounding the wire's metal core. It's important to do this carefully so there is no damage to the metal.
Number of Wires Allowed in Conduit - When running individual electrical wires inside conduit, there is a limit to how many wires are allowed. The maximum allowable number is known as the "fill capacity," and this depends on several factors, including the size of the conduit, the gauge of the wires, and the conduit material.
Wiring an Electrical Circuit Breaker Panel - The electrical panel, or service panel, is the power distribution point of a home electrical system. This is where all of the individual circuits of the house get their power and where they are protected by breakers or fuses.
Electrical Disconnect Switches - An electrical disconnect switch provides a means to shut off the power to a home's electrical system from an outdoor location.
Soldering techniques and procedures
Wave soldering is an in-line process in which the underside of the printed circuit board is treated with flux, then preheated, and immersed in liquid solder. In the next step, the board is cooled. This is the gist of the entire wave soldering process.
Step 1 – Melting the Solder
This is the very first step in the entire wave soldering process. It is the basic requirement of the process to melt the solder. The wave soldering machine has solder contained in a tank. The tank is heated to melt the solder. Appropriate temperature is reached to meet the right consistency, so that the process of soldering can be carried out further.
Step 2 – Cleaning the Components
This is a very crucial step to be carried out. The components to be soldered are cleaning thoroughly in this step. If any oxide layers are formed on the components, then they are removed. This is done by the process called fluxing. There are two main types of fluxing – corrosive (high acidity) and noncorrosive (high acidity).
Step 3 – Placement of the PCB
After melting the solder and cleaning the components to be soldered, the printed circuit board is placed on the melted solder. The board is held with the metal clasps of the machine, which ensure the firm positioning and placement of the PCB.
Step 4 – Application of Solder
Now that the PCB is placed properly, molten solder is applied, and is allowed to settle. Sufficient time is given to this step to allow the solder to settle into the joints completely, and ensure no bumps are formed.
Step 5 – Cleaning
This is the final step in the wave soldering process. Any flux residues formed during the process are cleaned in this step. The circuit board is washed and cleaned with the help of de-ionized water and solvents.
Use of lead-free soldering technology
The choice of lead-free products for wave soldering or through-hole soldering is decided according to specific design parameters and product-use demands of the final assembled PCBs.
Performing different types of splices
Rat Tail or Pig Tail - This kind of joint is commonly used to join two or more conductors inside the junction box. It is suitable for service where there is no mechanical stress when wires are to be connected in an outlet box, switch, or conduit fitting
Y-Splice - This method of wrapping is generally used on small cables because the strands are flexible and all can be wrapped in one operation.
Knotted Tap - joint all the splices discussed up to this point are known as butted splices. Each was made by joining the free ends of the conductors together.
Plain Tap Joint - This is used where the tap wire is under considerable tensile stress circuit.
Aerial Tap - This is used as a temporary tap usually done in construction sites. The easy twist will facilitate tap wire movement.
Duplex Cross Joint - This is a two-tap wire turned simultaneously and is used where the two tap wire is under heavy tensile stress.
Western Union Short-tie Splice - This is the most widely used splice or joint in interior wiring installation to extend the length of wire from one point to another.
Western Union Long-tie Splice - This is used extensively for outside wiring to extend the length of wire from one end to another.
Cross Joint - The same application is done as in plain tap and the only difference is that this tap is a combination of two plain taps place side by side with each other.
Wrapped Tap or Tee Joint - This is used on large solid conductors where it is difficult to wrap the heavy tap wire around the main wire.
Use of diagnostic equipment
Multimeter - Also known as a VOM (Volt-Ohm meter), a multi-meter is a handheld device that combines several measurement functions (such as voltage, current, resistance and frequency) into a single unit.
MegaOhmmeter - Most commonly referred to as simply a “megger”, a megohmmeter is a special type of ohmmeter used to measure the electrical resistance of insulators.
Low-Resistance Ohmmeter - Often called a DLRO in the field, the low-resistance ohmmeter is used for making high-precision resistance measurements below 1 ohm. Low-Resistance ohmmeters produce low voltage DC currents via battery power with outputs of up to 100A.
Hipotential Test Set (AC/DC/VLF) - Dielectric withstand (or hipot) testing checks for good insulation in medium and high-voltage apparatus, the opposite of a continuity test. Insulation is stressed above nominal values to ensure minimal current leaks from the insulation to ground.
High Current Test Set (500A to 15000A+) - A high current test set may consist of two pieces known as a “control unit” and an “output unit”, or these functions may be combined in a single package. Low voltage, high current outputs are used for primary-injection testing of low voltage circuit breakers
Secondary Test Set - Circuit breakers with solid state and microprocessor trip units can be tested by injecting secondary current into the trip unit directly rather than passing primary current through the CT’s using a high current test set.
Relay Test Set - Relay test sets are fitted with multiple sources to test solid-state and multi-function numerical protection, each voltage and current channel is operated independently to create different power system conditions.
Power Factor Test Set - Power Factor Test Sets provide a comprehensive AC insulation diagnostic test for high voltage apparatus, such as transformers, bushings, circuit breakers, cables, lightning arrestors, and rotating machinery
Winding Resistance Test Set - Winding resistance measurements are an important diagnostic tool for assessing possible damage to transformer and motor windings. Winding resistance in transformers will change due to shorted turns, loose connections, or deteriorating contacts in tap changers.
Transformer Turns Radio (TTR) Test Set - The TTR test set applies voltage to the high-voltage winding of a transformer and measures the resulting voltage from the low voltage winding, this measurement is known as the turns ratio.
Current Transformer Test Set - CT test sets are small, multi-function units designed to perform demagnetization, ratio, saturation, winding resistance, polarity, phase deviation, and insulation tests on current transformers.
Magnetron Atmospheric Condition Test Set - Traditional field testing of vacuum interrupters utilizes the hi-potential test in order to evaluate the dielectric strength of the bottle, this test produces a go/no-go result that does not determine when, or if, the gas pressure inside the bottle has dropped to a critical level.
Ground Resistance Test Set - Ground Resistance Test Set - The ground resistance test set works by injecting a current into the earth between a test electrode and a remote probe, measures the voltage drop caused by the soil to a designated point, and then use Ohm's Law to calculate the resistance.
Power Recorder - Power recorders are devices used to collect voltage and current data which can be downloaded into software in order to analyze electrical system conditions.
Continuity testing and grounding
Polarization Test
Polarization Test
A polarization test is usually performed as part of one of the other tests, such as a line voltage leakage or a hipot test. It is a simple test that verifies that a product supplied with a polarized line cord (either a 3-prong plug or a 2-prong plug with the neutral prong larger than the other) is properly connected.
Evaluation Phase
Activity 4: Identification
The link is provided below.
D. Generalization
The teacher will ask someone to wrap up the lessons
Activity 5: Identification
Link is provided below
VI. Assignment
Directions:
Choose at least 5 different types of splice
Make a video of yourself performing various types of splices and explaining their definition.
Link is provided below.
Reference:
safetyrisk.net/wp-content/uploads/2013/09/OHS-Policies-and-Procedures-Manual.doc
www.sheffield-pottery.com/v/vspfiles/downloadables/electrical_theory_and_application.pdf
electricalclass.files.wordpress.com/2015/12/hand-tool-best.pdf
janmclaine.wordpress.com/2017/03/03/first-blog-post/
testguy.net/content/296-Test-Equipment-101-The-Basics-of-Electrical-Testing
www.chromausa.com/applications/safety-compliance-test/ground-bond-tests/#:~:text=The%20purpose%20of%20a%20ground,the%20%E2%80%9Cgreen%E2%80%9D%20wire)
Page updated
Google Sites
Report abuse