INSPECTION AND TESTING OF INSTALLATION 1

                                                 

Periodic inspection and testing of internal wiring installations is necessary. Internal wiring should be checked every year for safe operations.

While carrying out inspection and testing of internal wiring installations, following points should be checked:  Incoming Service Line Connection

Check and ensure the following:

1.            Service line coming in to the premises is properly terminated and brought in

2.            Check for fuse wire rating on each of the phases so as to ensure it is of correct rating

3.            Check for wire sizes to be of correct size to carry the required current

4.            Check for earthing to be properly maintained at the service line side

Main Switch Board

A main switch board exists at the point of termination of service line. Supply is provided through this board in to the premises.

1.   Ensure that the main switch board is closer to the point of supply in the premises

2. Check for fuses / circuit breakers used of adequate sizes for all phases

3. Check for correct ON/OFF working of Main Switch. A main switch plays a very important role as it helps to switch off the complete supply of the premises in case of emergency / repairs. It should always be in good working condition.

Check for any mechanical faults in switching operations that might cause it to remain continuously in ON state. This may be problematic in emergency cases when the electrician wants to switch the supply off

4.  Ensure that the Switch board assembly is well covered to protect against rain / weather conditions

5.   Inspect to see that you are clearly able to trace the neutral and earthing wires in different colour

6.            Inspect the electricity meter connections are properly fastened

Internal Wiring Circuits

Internal Wiring Circuits are to be checked for following points:

1.            Ensure that each circuit branching out of Main Switch board has a connected load of not more than 800 watts or 10 points

2.            Test for Insulation resistance of conductor and earth to be as per IEC specifications

3.            Electrical resistance from connection with Earth electrode should not be more than one ohm

4.            Ensure metallic covering of iron clad switches, distribution boards are properly earthed

5.            Test that that leakage current is less than 1/5,000 of maximum supply current.

Key Tests to be performed for Wiring Installations

1.            Insulation Resistance Test:

In this test, the insulation resistance of a wire is tested to ensure that there is no leakage current flowing through it. As per IE rules, the insulation resistance between wiring and earth should not exceed 1/5,000 of the current flowing through it.

The test is performed using “Megger” instrument. In this, main switch is put in OFF condition and all the lighting connections on the circuit are short circuited. The Megger is connected between line and the earth. Megger is then rotated to generate voltage and then the reading on the dial of Megger is noted

The insulation resistance should not be less than 50 Mega-ohm divided by no. of circuits. The insulation resistance per circuit is calculated as 50 Mohm. If the result value is more than 1 then it should be considered as 1 mega-ohm. In no case this value should be less than 0.5 mega ohm.

2.            Earth Continuity Test:

This is second most important test for safety of installation.

All metal clad switches, metal parts, covers, conduits must be solidly connected to earth. In absence of this, there could be a severe damage to the whole electrical installation, appliances connected to it. In adverse events, the leakage current flowing through it may cause severe electrical shock to the person coming in physical contact with it.

In order to test this, the main switch should be in open position. All other circuit contacts like bulbs and switches should be ON position. The Earth continuity tester is then connected between the switch / conduit and an independent earth. The tester will indicate the value of resistance. In all cases the value should not exceed more than 1 ohm. If the value appears higher than 1 ohm it indicates that the switch / conduit is not properly earthed.

Lighting systems for substations and plants (LV and MV)

“I am sure nobody would want to grope around energized equipment, rotating shafts, variable drives, and power tools in the dark or dim light. Illumination is vital for all industries. The risk is injury and death. For this reason, it is important to install proper lighting system in all sections.

Experts suggest that 75% of the lighting should be primary while the remaining for emergency lighting systems accounts for 25%. The following highlights the standards, emergencies lighting, monitoring, and control as well as recommended locations.”

Standard Lighting

Industries use the following lamps. Lamps, in this case, means equipment that produces light

• Incandescent lighting produces light when the included filament is energized. Used for general lighting, offices and living quarters

• Reflector lamps: similar to incandescent lights but with an included reflector. Applications include emergency lighting and general lighting

• Gas discharge lamps produce light through the excitation of a contained gas. Common types include fluorescent, metal halide and sodium vapor lamps and are used for general industry illumination, and pathway lighting. 

The metal halide lamps feature high color rendering suitable for assembly lines and inspection areas while sodium vapor lamps feature low rendering, thus are suited for lighting pathways and yards.

Most plants have an included step-down transformer to provide the right voltage for the lighting system from the grid. The separate transformer for lighting prevents frequent blackouts due to the voltage fluctuations associated with the primary transformer feeding the LV and MV equipment. The three-phase supply should have 4-pole switches or circuit breakers. This ensures that the neutral is always open when the panel is de-energized during maintenance.
From the panel, each sub-circuit should be a single-phase consumer circuit, with one wire from the single phase, and the aforementioned neutral from the panel. Alternately, install a single-phase two-winding transformer to ensure that the voltage matches for all the light fittings.

Other than the general illumination, the following are key lighting installations:
• Main white lights: installed to mark out the substation or industry and usually have a range of 15 miles in every direction of approach
• Subsidiary lights: installed to mark any vertical extremities and irregular building projections
• Secondary lights are placed next to the main white lights in case the latter fail
• Emergency lighting

Emergency Lighting
Emergencies in substations and plants are always significantly risky considering the equipment and voltages in the installation. Prompt evacuation from the premises is important. The event may result in primary power loss, so emergency lighting is crucial in such situations. The evacuation should not be a risk by itself due to poor lighting.
Provide readily available portable lamps and torches near exit doors, operational rooms, main plant areas, accommodation quarters, control room and OIM offices. The lamps should already be fully charged in case of emergency, with conveniently placed and functional charging units.

Additional Tips
• Install fluorescent lamps to illuminate rotating shafts to avoid the stroboscopic effect associated with other lights. This effect makes the shaft appear stationary when in reality rotating at high speeds, thus increasing chances of injury or death.
• Subdivide lighting schemes within distinct modules: this increases chances of having illumination when the system fails. 
• During the lighting system design stage, ensure the farthest lamp receives a minimum of 95% of its nominal voltage. This entails proper cable sizing, and assumptions that all the fitting are energized during the design stage. 
• Install light is fitting control in non-hazardous areas for easy accessibility.
• Use the lighting fittings that fit the designated area. For example, exterior illumination and areas where water sprays are used, such as modules that require water-based firefighting systems use all-weather lights and waterproof electrical fittings. Other non-hazardous lighting systems are okay for areas such as control rooms, computer rooms, accommodation areas and offices

• Maximize on the use of natural lights through using transparent roofing and openings
• Replace standard lamps with the more energy efficient variants in the market
• Layout modification for optimum illumination
• Interior color selection aids in illumination and energy savings

Navigation and Control
The best option for a substation is to install an automatic system to switch on the lights a quarter of an hour before sunset, and to sunrise and in times of reduced visibility, as well as a manual override system for unusual conditions, or during maintenance times. The accompanying user interface in the control rooms should indicate the real-time state of every light and fitting.
Addition systems in case automatic switchover to a secondary system in case the white lights control system fails, with a corresponding indication in the control room.

SOLAR – HELP REDUCING YOUR ELECTRICITY BILL- SMART HOMES

Solar Power Technology is mature enough to bring great benefits in many regions of the world. I’m sure by now we all know these benefits, smaller electricity bill, endless energy supply, green technology.

As a company with proving tracking record in solar panel procurement and installation, our client might want to ask one or two question about it. We are here to give you a very good answers….
Things to consider when buying, designing and installed solar panel to generate electricity
In residential areas a solar power system will most likely connected to the main power grid. Because of this a first step will be to find out what regulations are in place in that particular region with regards to this type of installation. If it is an area you don’t know a good place to get advice is local retail shops that sell solar power equipment.

The second step is to determine how big this system needs to be. This is a more complex task and requires that you know exactly what type of operation is required. There are systems that can function entirely off grid, systems that are connected to the grid; you will need to determine if a battery bank is necessary or desired. Mostly in Nigeria, off grid is the retail side that we are likely to consider.



Residential Solar Power 1
When the solar power installation is connected to the grid energy savings are possible because now the property owner will be able to sell the electricity he produces to the grid electrical company. In this case you will have to install an additional meter that measures the energy delivered to the grid. The more panels you have the more energy you will produce and more money can be saved from the electricity bill.
In off the grid installation the solar power system must be able to handle the desire load in any condition. In this case a battery bank that can store energy is very helpful during night time.

Determining the size of the system
Once you know the average annual power consumption you can apply certain formula to determine the required power capacity of the system. This calculation can be quite complex because there are many factors to consider like how much sunlight is in that area, number of hours with sunlight per day, and panel inclination.

No matter the type of installation some components are mandatory like the solar panels, the elements that convert the sunlight to electrical energy, the inverter that converts DC current to AC current, electrical panel to hold the fuses and switches that provide protection of the installation.
It is also good practice to install a meter to monitor energy produced. If a battery bank is necessary you will need a battery charger and the batteries themselves. In some cases you might need a transfer switch to route power distribution from grid to solar system and vice-versa.
Solar Power System has benefited by an increased interest year after year and will become even more popular as technology will rise their efficiency and allow it to work well in areas with less sunlight.
Homes with solar panel the provide alternative electricity supply are today called SMART HOMES

TOP 10 Power Quality Problem

Around the globe, we all know the effect of fine, cleaned electrical power system, you'll all agree is positive, it contribute a lot that we can't mentioned here, if we have to focus on these positive effects, part by part, sector by sector and in all ramifications, 1000 pages of books will be birth,still, we will have more area untouched. In Africa generally, i believed most people especially in rural area are naive towards quality of Electricity they are use to, all they are interested "Let there be light and it is" by switching on light. The Quality, process, Transmission and even billing is not of interest. We are here to touch top 10 electrical power quality problems. We will love you to share it all...

Before we move on to the top 10 power quality problems, let us first understand what power quality is, and why it has become the most vulnerable issue pertaining to power supply in the recent years.

Power Quality: It can be defined as a measure of voltage parameters that synchronize with the phase and allow electrical systems and equipment to function normally without causing any loss to their performance and durability. Simply put, power quality is a factor that determines how fit and safe the electricity is, from a consumer’s point of view.

Why it has become the most vulnerable issue?
Though, power quality has been an issue with electrical power since it was invented, it has become a very popular issue in the recent years. This is because, most of the data losses,, Electrical Machine stalls, equipment's failure, computer reboots and malfunctioning of the electric devices are due to inferior power quality.

The following are the top 10 power quality problems ranked according to their impact on electrical systems and devices, with first one being the most vulnerable cause:

1.Voltage Sag

Explanation: This is the most common problem in which voltage drops from 10 to 90% of the normal power frequency voltage. This may last up to one minute.

Consequences: Malfunctioning of computers, IT equipment, electro-mechanical relays and electric rotating equipment, etc.

Appropriate solutions: Using voltage regulators, power conditioners, uninterrupted power supply systems can prevent the above mishaps.

2. Short Interruptions

Explanation: Short interruptions occur when power supply is completely nullified for a few milliseconds, and sometimes, up to two seconds.

Consequences: Protection devices get tripped, inefficient data processing or loss of data, sensitive electric equipment may stop (PC’s, ASd’s, etc.)

Appropriate solutions: Using power conditioners and uninterrupted power supply systems can prevent the above mishaps.

3. Long Interruptions

Explanation: Long interruptions occur when power supply is completely stopped for more than two seconds.

Consequences: All electric equipment stop functioning.

Appropriate solutions: Using Gen sets, Power generators, solar inverters, electric home inverters, etc., can provide temporary solutions.

4. Voltage Spike
Explanation: This takes place at a lightning speed. A sudden spike in the voltage may occur due to lightning strikes, during thunderous storms or due to sudden connection/disconnection of heavy loads from the mains. These spikes generally last only for few microseconds.

Consequences: Destruction of highly sensitive components such as microprocessors, insulating coils. Can also cause electromagnetic interferences (EMI’s).

Appropriate solutions: Voltage regulators, UPS can save your electric equipment from low to medium voltage spikes.

5. Voltage swell
Explanation: Voltage swell is defined as a brief increase in the voltage for a few seconds. This is generally caused due to defective transformers, inefficient power sources or sudden operation of heavy loads.

Consequences: Lights and screen displays flicker, data loss, sensitive equipment may stop or get permanently damaged.

Appropriate solutions: Voltage regulators, power conditioners and UPS can prevent your devices from voltage swell.

                                                     

6. Harmonics

Explanation: Harmonic distortions are associated with both voltage and current waves in the sinusoidal form. Though voltage harmonics are present, most of the harmonics are caused as a result of current distortion. And prominent electric distortion takes place due to the presence of variable electric loads on the power system, also known as non-linear loads.

Consequences: Increased resonance, overheating of equipment as well as cables, EMI’s, tripping of protectors, etc.

Appropriate solutions: Using passive filters, active filters (costly option), delta-wye transformers, k-rated transformers can prevent different types of harmonic distortions. Also, increasing the size of conductors can help reduce impedance and thus the harmonic distortion.

7. Voltage Fluctuation

Explanation: Arises due to oscillations in voltage value and amplitude, when modulated by signal waves having frequency less than or equal to 30 Hz.

Consequences: Lights and screen displays flicker, data loss

Appropriate solutions: You can avoid voltage fluctuations using voltage regulators or power conditioners.

8. Noise

Explanation: Noise comes into picture when the frequency of a power system is superimposed by signals having higher frequencies.

Consequences: Simple disturbances in IT and electronic equipment (no serious damage occurs)

Appropriate solutions: Noise can be reduced using proper bypassing ad filtering techniques.

9. Voltage Unbalance (VU)
Explanation: Voltage unbalance is a result of frequency variation in a three phase power supply which arises due to unequal differences between the phase-angles of the three respective voltages.

Consequences: As a result negative sequence may be inducted into the system which can be harmful to the phase loads (most vulnerable equipment in such cases is, three phase induction motor).

Appropriate solutions: Using PWM converter as a STATCOM controller or as an active filter can reduce voltage unbalances considerably.

10. Brownouts
Explanation: Brownout is a continuous low voltage power supply state. It occurs sparingly in summers (or when the demand of power outweighs the supply).

Consequences: Inefficient data processing or loss of data and malfunctioning of electrical equipment.

Appropriate solutions: Voltage regulators, UPS and power conditioners can save your electric equipment from brownouts.

Conclusion

Since the invention of electricity, there have been problems regarding power quality. Many measures were taken to control loss of power when distributed over long distances, such as attenuation and polarization. Unfortunately, even now, the problem persists.
However, one can reduce; if not entirely eliminate the power quality problems, with the above mentioned electric equipment as a solution for each problem.

The Importance of Equipment Specifications

Introduction

As with any other business or profession, a clear write-up of requirements is important for purchase and procurement. This is especially important for electrical equipment due to the high significance of tolerances, ratings and size.

Whether for new projects or replacements, a specification document is crucial.

Purpose

The chief purpose of equipment specifications is to ensure the purchaser acquires the required equipment, rather than what the supplier thinks is right. You might think that the difference in interpretation is a minor detail. However, considering the detriments associated with wrongly rated electrical equipment, it is vital you get the right specifications.
Do note that suppliers of electrical equipment often serve a wide market and industries, from residential installations, commercial projects to large plants. For this reason, narrow down to your exact niche and area of use. A variable drive for underwater installations may require different requirements from similar equipment for land use due to the prevailing environmental and operating conditions. For example, a simple LV motor operating in desert conditions may require a longer frame size than for cold and windy locations due to extra cooling requirements.

Features
A typical equipment specification consists of the standard equipment rating, and more details based on the options available. Over specifications over the available options is considered impractical and unnecessarily expensive, unless the project is highly sensitive and dependent on the extras. In such cases, the manufacturer may assemble customized equipment, often at a very high cost. The feasible option is to purchase the most suitable options, and then design the power system around the equipment to suit the requirements.
The following are the primary features of equipment specification :
• Crucial requirements based on the market standards
• Desirable requirements based on the available options
• Incidental features based on ‘nice to have’ feature such as equipment color. These features are usually not crucial to performance.

At Artemis Consulting Limited

Format

Introduction: a brief description of equipment installation location, installation type, and nature of the installation environment

Scope Of Supply: a summarized list of the primary equipment constituents, as well as the components to leave out. This reduces chances of misunderstandings during the quotation and delivery
Service Conditions: an in-depth description of the installation conditions including humidity, temperatures, winds, moisture levels and chemical contamination. It can also include a brief description of the indoor or outdoor conditions depending on usage.

Standards: highlights the most appropriate and relevant international norms desired. Ensure that the standards are updated and clearly listed to minimize chances of confusion during quality assurance tests. To be on the safe side, specify the standards to avoid uncertainty due to similar standards depending on region and metric units.
Definitions: misinterpretation is rife when sourcing electrical equipment. It is risky to assume that the manufacturer or supplier is well versed in the industry-specific jargon. Clearly define such terms and phrases in the specification, especially when it has different meanings in different standardizations.

Performance Requirements: clearly state the expected service life of the equipment, both lifetime, and in-between maintenance schedules. Though this depends on the equipment type, it is easy for an engineer to look up and specify the expectations of large electrical equipment such as generators, motors and such. Do note that the mode of operation, as well as the rated duty for LV and MV equipment, usually has a significant impact on the performance requirements; therefore ensure you highlight this factor.

Design Requirements: clearly define the degree of protection required based on the area of usage. Outdoor, indoor and levels of hazards require different design and construction requirements, therefore, highlight this factor. In the same vein, underline crucial fittings such as protective devices, circuit segregation, lifting points, and such. However, ensure that you check out the data sheet first as most of these will already be included.

Inspection and Testing: the purchaser should pay particular attention to this factor, as mistakes are costly. The first test is a physical inspection before purchase. Ensure that you clearly state the required inspections and test before purchase and delivery. To be on the safe side, use international standards as references and acceptable limits for the best results and to save time.

Appendices: contains definitions, and extra information not highlighted in the other components such as noise information, interlocking data and others

Any functioning electrical system, whether SCADA or variable speed drive system is an amalgam of compatible individual elements. With this in mind, approach the procurement with a combination of compatibility and eventual functionality.

ARTEMIS CONSULTING LIMITED

Artemis Consulting Limited is a service based engineering company based in Nigeria but aimed to be recognized worldwide. The service rendered are numerous but it targets is to solve practical engineering problem faced in Nigeria, Africa and global world. Though, Africa itself was known to be facing a lot of problem in Electrical Power system's  Generation, Transmission and Distribution. Artemis will be able to go far more than these issue that we will be discussing here, we will go into the root, Plant design, construction, Installation and Maintenance. What and what are the features to considered as related to the African Power crisis. High voltage and Low voltage in transmission system will also be touched. Under distribution of Power we will be looking at optimization of power distribution, equipment's reliability and disturbance in general. We will also touches base with safety and standard in electrical wiring design and installation. Power system Analysis, control and protection are our target to spread what we know

We are into Project Management too, we will go into that and touches what our local engineers lacks that really affect our infrastructures today, both in Nigeria and Other African countries.

Renewable energy, good. Today the whole world is clamoring for how we can save our world from effect of global warming. Several world conferences headed by United Nation Secretary General Ban Ki Moo and several other has been organised. At this blog we will touch using of renewable energy to replace bad carbon component that continues to shrink our ultimate ozone layer.

This blog is just to useful both for student of Engineering (because Engineering management will be touched), Company owners, Lecturers and any other who is interested in all mentioned above.

You can see we have a lot to do for the next five years or more. There are new innovation in the field we are talking about here which we will love to share with all our readers. Did you hear about new discovery of "Gravitational wave" this is the work of our Mentor Sir, Albert Einstein, there's a lot still going through the study of Relativity theory.

The Scope is just too numerous to touch, 20 years this blog is alive with new innovations and discovery who knows whether we can give birth to our generational Einstein through this blog.

Question for the readers? Who is the first Scientist or Physicist or discover Gravitation?

This is my first Blog, i got know gift for the correct answers (maybe later) but i want to challenge my readers to go more into research and together we can contribute how we can make this world better place to be.

Babatunde Kolawole is my Name.



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