SOCKET OUTLET WIRING AMAZING PROCEDURE

What is Socket Outlet?

Fig: Radial and Ring Socket Outlet Wiring Methods

A socket Outlet is a device with protected current-carrying contacts intended to be mounted in a fixed position or permanently connected to the fixed wiring of the installation.

The purpose of socket outlet installation with other accessories is to enable the connection of a temporary load to it with a flexible cord, plug, or flexible cable.

Types of Socket Outlet Connection

Considering the location and requirements of the wiring area, socket outlet wiring connection may be one of the following three types:

What Is The Difference Between DOL and Star-Delta Starter?

Why Use Direct Online (DOL) and Star-Delta Starter?

DOL means the motor is connected directly to the Line (Direct On Line) using one contactor with no starting circuit to lower the high starting current. Typically, the Delta part of Star-Delta.

Star-Delta uses two contactors, one to start at a lower voltage in Star and one to run at a higher voltage in the Delta configuration.

For example, a 400V, 3-phase power supply Star applies phase to neutral or 230V. Delta applies the full phase to phase 400V.

Relays: LEXIS OF RELAY

What Is Relay? How Do Relay Work?

 Relay a device that opens or closes a contact when energized. Relays are most commonly used in power systems, where their function is to detect defective lines or apparatus or other abnormal or dangerous occurrences and to initiate appropriate control action. 

When the voltage or current in a relay exceeds the specified “pickup” value, the relay contact changes its position and causes an action in the circuit breaker. A decision is made based on the information from the measuring instruments and relayed to the trip coil of the breaker, hence the name “relay.” Other relays are used as switches to turn on or off equipment.

 

CT (CURRENT TRANSFORMERS) IN ELECTRICAL DISTRIBUTION SYSTEM

What is CT or Current Transformer in an Electrical Distribution System

The CT an abbreviation of Current Transformer is a type of instrument transformer that is used to measure the current in AC or Alternating Current systems, taking the reduced amount from its secondary winding which is proportional to the primary winding that is being measured.

Different Types of Electrical Switches and Their Use

Different Types of Electrical Switches Normally Used in Circuits

There are so many types of electrical switches available from very simple to very complex switches used in the electrical circuit controlling systems. 

The switch may be different types but the basic function of the electrical switch is to open or close. The meaning of an electrical switch is to open or close the electrical path to equipment. 

RESIDUAL CURRENT DEVICES: WHAT IS RCD AND WHAT DOES IT DO?

Fig-Residual Current Device Connection Procedure

What are the Residual Current Devices?

By definition, a residual current device is a current-activated circuit breaker used as a safety device for mains-operated electrical tools and appliances.

What are the Ring Circuit and Radial Circuit?

What Is Radial and Ring Circuits?

Think of a simple Circle that has a radius and periphery. The electrical circuit in your wiring system that looks like a radius is called a Radial circuit and which one looks like a periphery or ring is called a Ring circuit. Oh! this definition seems to layman, not professional; let's know the details-  

A radial circuit is an electrical circuit where the feeders to each socket are taken directly from the consumer unit or distribution board (DB) or circuit Breaker (CB) like a 20A MCB. 

A ring circuit is an electrical circuit that has two feeders both coming from the same 32A MCB or RBCO in the consumer unit and heading off to different ends of a loop circuit. Ring circuit also known as Ring Main circuit.

Why Earth Pin Longer and thicker than Others Live or Neutral Pin in a Three Pin Plug?

Fig: Three-Pin Plug

Is a 3-pin Plug provided for better safety and to prevent electrocution or is protection no longer required?

Have a look! The earth pin of a three-pin plug is heavier (longer and thicker) than others two-phase and neutral! But, we know earthing or grounding wire does not carry continuous current, whereas phase wires do. Do you realize? Why this guy is heavier? If not, let's research.

LOAD DISTRIBUTION AND FINAL DB WIRING

Phase-wise Load Distribution may possibly be during Final DB (Distribution Board) wiring. Equally load distribution in the final DB or physical load connected to an electrical circuit is important to keep the load balanced in each of the three phases.

Importance of Load Distribution in Final DB

All loads of premises become connected electrically through the final DB. Equally distributing the load on phase Read, Yellow, and Blue; it’s promising better performance of other accessories like protective devices RCD, Circuit Breaker, switches, fuses, cables, etc.

RCD for Earth Leakage Protection

Earth Leakage: Electricity is carried by conductors that are supported above the earth or inside the earth but are electrically isolated by insulators which prevent the electricity from neutralizing itself as it would if it shorted to earth. However, there is some very small leakage across these insulators, especially aerial insulators during wet or humid conditions. This is called earth leakage.

WHAT SHOULD BE BATHROOM WIRING STANDARD

Fig: Architectural Drawing for a bathroom wiring

What Is The Specialty For Bathroom Wiring Than Others? 

Yes, I am not meaning the latest fashion in your bathroom. As a talk from an Electrical Engineer, I am talking about your bathroom safety fashion from the point of Electrical Engineering. You may be thinking, why is different wiring needed for the bathroom, what is the problem with the same wiring.

From the note of experts on wiring accessories like Legrand, we can quote as follows that will give us a basic idea about bathroom wiring exceptions.

MCB: MINIATURE CIRCUIT BREAKER OPERATION BASIC

What is MCB?

MCB is a device designed to protect an electrical circuit's wiring from the serious damage which would be caused if it has to carry a current that is too high for the diameter of its wires.

The MCB or Miniature Circuit Breaker is actually working for both electrical circuits' make or break switch and protection device fuse.

Likely normal fan/light switches, MCB also can operate manually as circuit ON or OFF; its specialty is, it can break the circuit automatically to protect from overcurrent.

Fuse is the very first protection device for an electrical circuit. A fuse is actually nothing but a thin wire that is enclosed in a protective casing and plugged into the circuit.

How to Calculate Fuse Rating for Electrical Appliances?

Different Rating's Fuses

Fuse Rating Calculating Guide

The function of a fuse is to break a circuit when a current threshold is exceeded. It’s a single-function device, and historically single-use. Calculating the rating of very basic protection equipment fuse, we use the thump rule just select a fuse rated 150% - 200% of the normal operating current of the specific circuit. But actually, there are numerous calculations are involved in determining an appropriate fuse rating. Frequently necessary to consider other factors- including ambient temperature, available energy during a fault, inrush current, etc.

In order to select the proper rated fuse protective device, the following parameters and criteria need to be considered:

1.    What is the normal operating current of the circuit?

2.    What is the operating voltage?

3.    Is the circuit AC or DC?

4.    What is the operating ambient temperature?

5.    What is the available short-circuit current?

6.    What is the maximum allowable I²t?

7.    Are there in-rush currents available?

8.    Is the protective device being used for short-circuit protection, over-load protection, or both?

9.    What are the physical size limitations?

10.Is the PCB surface mount or thru-hole?

11.Does the fuse need to be "field-replaceable"?

12.Is reset ability an issue?

13.What safety agency approvals are needed?

14.How will I mount the device?

15.What are the cost considerations?

Formula to Calculate the Fuse Rating

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There is a simple and basic formula for working out the fuse rating, voltage or wattage for each appliance:

P=VxI

Where,

P for power in Watts;

V for voltage in volt);

I for current in Amps.

The fuse rating can be calculated by dividing the power used by the appliance by the voltage going into the appliance.

I (Amps) = P (Watts) ÷ V (Voltage).

Fuse Rating Calculation for Motor

A fuse for a machine is rated on the load that the machine carries when running. For example, a 1-HP (746W) motor operating at 115V would draw 746/115 = 6.5A at full load, so theoretically a 10A fuse would be sufficient.

What is Fusing Factor?

Fusing Factor is the ratio of minimum fusing current and current rating of fuse.

Therefore, fusing factor = Minimum fusing current or current rating of the fuse.

The value of fusing factor is always more than 1.

Fuse Size Calculation Formula

Fuse Wire Rating: The melting point and specific resistance of different metals used for fuse wire is as below:

Metal	Melting point	Specific Resistance
Aluminium	240oF	2.86 μ Ω – cm
Copper	2000oF	1.72 μ Ω – cm
Lead	624oF	21.0 μ Ω – cm
Silver	1830oF	1.64 μ Ω – cm
Tin	463oF	11.3 μ Ω – cm
Zinc	787oF	6.1 μ Ω – cm

Many times we have to face some physical places limitation to choose the fuse or circuit breaker mounting sizes.

It is this reason that fuse and circuit breaker manufacturers have created a wide selection of components with varying physical sizes. Typically however, there are a trade-offs that the engineer must consider.

Generally speaking, the smaller the fuse, the less current and/or capabilities that the fuse or circuit breaker may have. For example, a sub-miniature fuse maybe limited to 15A whereas the larger 1/4" x 1 1/4" glass tube fuse can accommodate up to 40A.

Additionally, although the fuse can be smaller, the corresponding fuse holder maybe substantially bigger adding to the consideration.

Get download the pdf copy of full guide to calculate the fuse ratings:

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Read the article details on different type of Fuses and their uses

Star Delta Starter Line Diagram and Its Working Principle

Fig: Three Phase Motor connection diagram with a star-delta starter.

What is Star Delta Starter for Motor Starting?

Star-Delta starter is an electrical motor starting device, generally uses in big size motors to overcome some technical limitations. Star and Delta mean here 2 separate states of motor running, first Star connection and then Delta connection.

The starting current of any heavy electric motor can be more than 4 times the normal load current it draws when it has gained speed and has reached its normal running condition. 

To overcome this initial high current enchanting problem, such arrangement needs Star connection at starting time and if Star connection has sufficient torque to run up to 75% to %80 of full load speed, then the motor can be connected in Delta mode.

When the motor is connected to the Delta configuration the phase voltage increases by 173% and phase currents increase by the same ratio. The line current increases three times its value in star connection.

What Problem Starting Motor without Star-Delta?

We already know, if the motor starts simply when connected in Delta, the starting current would be huge just to be able to start the motor, not to running condition. To do this would require -

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v Large capacity circuit breakers to allow the start-up surge current to pass without immediately shutting the motor off.

v Oversized 3-phase power service cables require just for starting time, but the normal running time is not necessary.

v Large size of coils and contacts on the relays or contractors need to control the motor, but normal running time needs smaller sizes of them.

Sometimes, utility company also do not permits the big motor to start without a Star-Delta starter because of system instability due to switching transients. 

How Wiring a Star-Delta Starter for Motor?

Following the figure below, the power connection between magnetic contact for Main, Star, Delta and motor is shown in the schematic line diagram and wiring diagram for easy wiring.

Star-Delta Starter Connection with Control wiring

What is Important During Star-Delta Transition Period?

It is important that the break between the Star contractor switch OFF and the Delta contactor switch is ON because the Star contactor must be reliably quenched before the Delta contactor is activated. During the transition period of switch-over, the motor must be free running with little deceleration. It is also important that the switch over pause is not too long, it may generate a voltage of its own and this may add to or subtract from the applied line voltage.

That’s all for the Star-Delta starter for today; here in this article, we discussed only motor starting by 3 magnetic contracts Star-Delta, solid-state motor starters from different companies also are available in the market now.

Read: All Bangla News Paper

Phantom Loads Are Costing You an Extra Electric Bill

Cost Cut by Phantom Energy

Did you ever think, how much extra electric bill you are paying for Phantom loads? May not! but you will find it remarkable after reading this article.

What is Phantom Load?

Phantom load is standby load or standby power, Phantom load is also known as Vampire Power, Vampire draw, ghost load or leaking electricity. Phantom or Vampire power is the electricity consumption of any electrical equipment when it is kept in standby mode.

In our modern life, we use in our every house hues electronic devices like -

TVs

Computers/ Laptops

Cell Phones
VCRs, DVD players and DVRs
Battery operated many other devices
Clock Radios
Microwave Ovens
Coffeemakers
Power strips
Emergency lights

Charger Fans
Answering machines
Any device with a remote control

washing Machines
Any device with a clock

Water Cooler/ heater

Air Freshener
Any device that is programmable
Any device with a power light or standby indicator light, & many more.

These useless energy draws are known as phantom loads. The energy wasted over time due to phantom loads can be substantial. Identifying and eliminating phantom loads will lower your home energy use, save you money over time, and help lower your carbon footprint.

How Eliminate Phantom Load Costing From Your Monthly Electric Bill?

Using simple and easy tricks, you can identify your energy stealer and reduce your Phantom or Vampire electric load.

1. First of all, identify the prime sources of phantom loads that steal your energy and increase your month-end electric bill; then act to eliminate Vampire loads.
2. Unplug all the Phantom loaded devices like- cell phones, cameras and any other chargers as soon as the battery is fully charged.

3. Use smart strips or power bars to plug all your electronic devices like TV, DVD, Computer or Laptop, Cell Phone charger etc. that will be automatically turn off when you switch off the power bar.

4. Similar devices like Computer or Laptop, using sleep mode rather screen saver Phantom Power may reduce.

5. Energy Star labelled electronic devices use about 50% less energy than less-efficient models, so buying electronic appliances with energy star labels may reduce Vampire load.

To prevent phantom load finally we can say turn off the device by switching off the switch or removing the cable from the power plug.

To know more about energy saving techniques in detail about different kinds of loads, you better read the full article: 

ENERGY-SAVING TIPS FOR YOUR HOME APPLIANCES

Advantages of Phantom Load

We cannot treat the Phantom or Standby power negatively, usually, we are getting many advantages from Phantom Power.

1. Consuming Phantom Power is keeping the device alive, it is always not an entertainment device, maybe life-supporting or any emergency appliances.
2. The Standby Power supply may use some extra energy but shows the device is energized.
3. Using some extra power devices turn on very quickly and easily from the remote control area.
4. Using Phantom power it keeps the clock alieves for the system.
5. Using some Phantom Power it makes ensure the emergency charging equipment is fully charged and ready, etc. 

How Calculate Your Phantom Load?

We actually don’t know any standard to calculate Phantom Power but can estimate how much is consuming our appliances as Phantom Load, depending on the connected load it may not excite 70 to 90 watts. Phantom load depends on different brands of devices. Just to gauge about Vampire Phantom load calculation consider as below:

A television set may draw up to 40 watts;

A DVR unit may draw as much as 30 watts;

A laptop computer in sleep mode draw up to 50 watts;

In conclusion, we can say by eliminating Vampire Power phantom loads in the home and office, we can save up to 10% on our energy bills.

Who Will Give Perfect Advice in Bangladesh to Reduce Phantom or Vampire Power?

The main power utility company and agency list in Bangladesh is as below:

1. BERC (Bangladesh Power Regulatory Commission)
2. BPDB (Bangladesh Power Development Board)
3. APSCL ( Ashuganj Power Station Company Limited)
4. EGCB (Electricity Generation Company of Bangladesh)
5. NWPGCL (North-West Power Generation Company Limited)
6. IPP (Independent Power Producer)
7. RPCL (Rural Power Company Limited)
8. PGCB (Power Grid Company of Bangladesh)
9. DPDC (Dhaka Power Distribution Company Ltd)
10. DESCO (Dhaka Power Supply Company Ltd)
11. WZPDCL (West Zone Power Distribution Company Ltd)
12. SZPDCL (South Zone Power Distribution Company Ltd)
13. REB (Rural Electrification Board)
14. PBS ( Palli Bidyut Samity)

The above-listed utility companies and agencies are the main energy distribution and transmission companies in Bangladesh. They have a separate one-stop service desk to educate and learn the consumers.  Utility company educate their users to reduce the electricity uses like Phantom or Vampire Power and energy saving trips in daily use. You may find the best solution to reduce the Phantom loads and electric bill.

Standard Colour Code for Electrical Power Cable and Wiring

Basic Colour Code for Electrical Cable and Power Cable 

International standard IEC 60446 developed basic and safety principles for man-machine interface by marking and identification of electrical cabling and wiring system. 

Identification of equipment terminals, conductor terminations and conductors define basic safety principles for identifying electrical conductors by colours or numerals, for example in electricity distribution wiring.

Basic Color Code for Power Cable

The electrical power cabling system contains phases, neutral and earthing. To make sure a uniquely safe and easy identifying system some colour code system is followed internationally. 

Different region or country to country colour code may vary, but the basic is similar. The basic colour for phase is/or Read, Yellow, Blue; Neutral is/or Black, Blue, silver; Earthing is/or Green, Green-Yellow striped. 

For current flowing, it does not affect at all but makes it easier and safer for the crew.

Basic House and Industrial wiring colour code

Electrical wire is standard colour coding so that each wire is used or identified to identify what is in the circuit. Wires in India RGB mode is Red (Red) - Green (Green) - Black (Black). Here the function and importance of each RGB wire are different.

Red  - Red is a symbol of a wire face (Phase), in an electric circuit. This wire is the live wire which cannot be connected to any other red wire or black wire. The red wire is used in some types of switch legs. Switch leg is the wire that comes from the terminal below the switch, which heats up when the switch is switched on. This is the leg that turns off the load.

Black - Black wire is the Neutral wire of an electric circuit. This neutral wire is connected to a neutral bus bar inside an electrical panel. The bus bar is a conductive metal bar that attracts electric current for the purpose of distribution. The black wire can only be connected to the black wire, and not to any coloured wire. This earth wire or Neutral wire is not neutral due to its neutrality. It mainly takes unbalanced load ie to return current. This return current is not used and moves to the electric panel/board.

Green  - Green wire is grounding in an electric circuit. The green wire can only be connected to the green wire, no other wire. Usually grounding is not for wire lights and fans. Green wires are mainly used for socket purpose such as AC, Geyser, TV, Microwave, etc. Normally the switch has only 2 wires, neutral and phase.

U.S. Wire Colour Codes

The United States typically use the power cable wiring colour code as below:

For 120/208/240 VOLT AC WIRE or cable COLOURS

These systems are common in home and office environments.

1. Phase 1 - Black;
2. Phase 2 - Red;
3. Phase 3 - Blue;
4. Neutral - White; &
5. Ground - Green, Green with Yellow Stripe, or Bare Wire.

For 277/480 VOLT AC WIRE COLOURS
These higher-voltage systems are common for industrial motors and equipment.

1. Phase 1 - Brown;
2. Phase 2 - Orange;
3. Phase 3 - Yellow;
4. Neutral - Gray; &
5. Ground - Green, Green with Yellow Stripe, or Bare Wire.

For DC POWER WIRE COLORS
Solar power systems and many battery systems use DC (direct current) power, rather than AC (alternating current).

1. Positive (non-ground) - Red;
2. Negative (non-ground) - Black; &
3. Ground - White or Gray.

CANADIAN WIRE COLOUR CODES FOR AC POWER

In Canada, they use different colour code for electrical wire and wiring as per the Canadian Electric Code (CEC). The colour code for AC power wiring is similar to the code used in the United States like-

1. Phase 1 - Red;
2. Phase 2 - Black;
3. Phase 3 - Blue;
4. Neutral - White; &
5. Ground - Green with Yellow Stripe.

EUROPEAN (IEC) WIRE COLOR CODES

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Most European countries follow the wire or wiring colour code established by the International Electrotechnical Commission (IEC) which is published as IEC 60446 and  IEC 60445 in 2010 for AC branch circuits. The European wiring colour code is as below:

1. Phase 1 - Brown;
2. Phase 2 - Black;
3. Phase 3 - Grey;
4. Neutral - Blue; &
5. Ground - Green with Yellow Stripe.

Actually, the colour codes used for wires or wiring may vary. In some countries they used the colour code as per their specified local law; some countries are followed the international colour code. The user just needs to know the local practice to ensure electrical safety and correct wiring.

LOW VOLTAGE CONTROLED MOTOR WIRING SYSTEM

Fig- Low Voltage Motor Control Wiring Diagram

Three Phase & Single Phase Motor Starter Wiring System with Low Voltage Control

This article for the purpose to present the wiring system for both single and three-phase magnetic controlled motor with low voltage control (LVC) system.  Who think safety is the first priority for motor starter wiring, this article will help them. Motor ON-OFF switch is controlled herewith safe low voltage instate of the supplied power line.

The main and special feature in this motor control system is no voltage or low voltage protection system, low voltage control system, motor overload protection system refer to the figure below.

Main Safety Feature for LVC Motor Starter

Due to low voltage or no voltage, the magnetic contact will release the contact and motor will disconnect from the power. When power reinstates, if the motor restart automatically that may because of the dangerous accident for motor or human. To prevent this auto-restart a manual Start & Stop system is included here in this system. If temporary power failure then until the manual start, the motor will remain stopped.

The main supply voltage is dangerous for an electrical shock during coming very near to ON-OFF switch. But in low voltage controlling system what is provided here can eliminate the dangerous electric shock provability. Here ON-OFF system operates by the 24-volt low voltage that is very much safe for the operator.

If motor being overloaded and run for a long time then hues possibilities to burnout the equipment. Prevent motor damage from overload a motor overload protection system is also associated with this low voltage motor control system, a thermal overload relay which protects the motor from overloaded.

Every electrical installing and servicing should not try except clear understanding and qualified electrical personnel.

Three Phase LVC Motor Starter Wiring Diagram

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Refer to the above 3 phase LVC motor starter wiring diagram, if you study the wiring line and try to find the basic components of the diagram, you will find the following major components:

• magnetic contactor with coil;
• overload with heater;
• control transformer;
• start/stop station;
• connection and relation between different component.

Related article: Motor Star-Delta Starter Wiring Diagram

The unique feature of this wiring diagram shows the relation and connection of both power circuit and control circuit together which makes very easy understanding even for any new technician. The blue line shows the power line and the red line shows the control wiring. Also, all component are shown in black colour and grounding or earthing system shown in the yellow-green line.

Single Phase LVC Motor Starter Wiring Diagram

Actually, nothing special for single-phase LVC motor starter if you have the three-phase wiring diagram, just consider the phase number 3 is not in the above 3 phase diagram, then you will get a single phase wiring diagram. Single-phase motor terminal T1 & T2 and power source L1 & L2 will remain in the above diagram.

Hope you enjoyed, if you think it is helpful for others then share for them, or if you have a better idea write a comment in share space below.

Technorati Tags: Low Voltage Motor Control, Motor Starter Wiring,3 Phase Motor,1 Phase Motor, Wiring Diagram, Motor Engineering, LVC

SMOKE DETECTOR INSTALLATION WIRING GUIDE-NFPA 70 ARTICLE 760

Fig: Smoke Detector Wiring Diagram

The Guideline for Smoke Detector Installation Wiring as per Manufacturer Instruction and NFPA 70 Article 760

In the Fire Alarm System, smoke Detector installation wiring should as per international standard like NFPA 70 article 760 and NEC- National Electrical Code and of course followed by manufacturer instruction manual wiring diagram.

You must be considering that smoke detector installation wiring for fire alarm system is very different from typical House Wiring or Electrical Wiring system. The main purpose of fire alarm system wiring is to be able each sensing detector like smoke detector to continuous electrically supervision.

To make sure the fire alarm system completely operating without any trouble, the very first and basic rule is to follow the manufacturer’s instruction on smoke detector installation wiring diagram.

Smoke Detector Installation Wiring Techniques

The rules of electrical supervision of smoke detectors are not very complex. However, the technician should be familiar and well experienced in the fire alarm system installation works.

The best and easy technique for smoke detector installation is follow the manufacturer’s wiring installation guide. Manufacturer’s wiring guide shows connections in a certain manner to provide accommodation of supervision requirements.

Over-emphasizing the manufacturer’s wiring guide, portion of the circuit may not work for proper supervision, while a short or open circuit occurs.

Smoke Detector Installation Wiring Guidelines

In the incorrect portion of the above figure wiring diagram are shown a very simple mistake known as T-tapping wiring. 

In first portion of figure indicated incorrect wiring, smoke detector-1 is wired as T-tapping. This T-tapping is very correct wiring technique in typical electrical wiring system, but not in smoke detector installation wiring. 

This smoke detector may operate correctly in alarm conditions, but if disconnected from the wiring no trouble would be detect in fire alarm system.

In the correct portion of the above figure shown correct installation wiring method for smoke detector-1 where fire alarm panel will indicate trouble if any loss of supervision occurs in any point of the circuit.

Also some smart fire alarm systems are available in the markets that allow T-tapping smoke detector installation wiring. Finally, before the system put into operation, should check the short circuit, open circuit, grounding and each detector as per manufacturer’s instructions.