What is a Current Transformer Used For?

A current transformer is used to reduce electrical current in an AC circuit to allow safe measurement and monitoring of power. It produces a lower current in the secondary coil that is in direct proportion to the current in the primary coil. This allows voltage to be measured with minimal risk. This guide will look at the principles and applications of current transformers.

What is a transformer?

A transformer is the simplest possible piece of electrical machinery, having no moving parts. Discovered in the early 19th century by Michael Faraday, in its simplest form it consists of two coils of insulated wire, known as primary and secondary windings, magnetically linked by means of a core. This core usually consists of iron or steel although other materials are also used depending on the function of the transformer. The primary winding is supplied with alternating current, this, in turn, sets up an alternating magnetic flux in the core, producing an alternating current in the secondary winding. The secondary voltage is proportional to the number of turns in each winding, for example, a transformer with 1000 turns on the primary winding and 10000 turns on the secondary winding will give 1000 volts on the secondary when 100 volts are applied to the primary. The transformer is the simplest method of converting one voltage to another for any purpose.

The Current Transformer

For high voltage work it is not convenient or safe to connect electronic equipment used for metering directly to the supply, therefore a current transformer is used to reduce the current to a more manageable level. This current is then safely read, usually in amperes. Current transformers can be broadly divided into three groups.

Toroidal Current Transformer

These are ring-shaped transformers with an insulated circular core around which are the wire windings. The voltage is measured by passing the cable carrying the current through the hole in the centre of the ring.

Wound Transformer

This is, in essence, the simplest type transformer described earlier, where the output of the secondary winding is proportional to the ratio of the two windings.

Bar Type Current Transformers

Similar to the toroidal transformer, instead of passing a cable through the centre of the ring, a bus bar is used as the primary conductor. This means the conductor is a permanent part of the circuit.

Purpose and Applications

Without the aid of a current transformer, modern power systems would be impossible. From overhead power cables with a colossal 400,000 volts to the tiniest electrical circuits, the humble current transformer is found nearly everywhere.
At the larger end of the scale, there are the current transformers found in power stations and electrical substations throughout the National Grid. These are used for recording and monitoring current and are part of the space age looking apparatus you see when passing an electrical substation.
On a smaller scale, you will also find a current transformer in your electricity meter at home. In this case, it will be measuring and recording usage of electricity to enable the supplier to produce an accurate bill.
Handheld current transformers are also now very common. These have a large clamp that closes around the cable giving an accurate reading of current without the need to dismantle whatever system you wish to measure.

Protective Current Transformers

In addition to their role as current reducers, current transformers can also be used as inputs for protective relays which will isolate the affected circuit if an abnormal or fluctuating current is detected.


As transformers are often dealing with very high voltages, safety is of high importance. They should only be installed by a qualified electrician and the manufacturer’s instructions should be adhered to.

Terms related to Current Transformers

Ratio-Refers to the turns ratio on the primary and secondary windings.
Rated Primary Current-The value of the current to be transformed.
Rated Secondary Current-The value of the current in the secondary winding that is to be read.

Burden-The burden is the maximum load that can be applied to the secondary winding. Accuracy Class-This defines the most suitable transformer for the task. Class 0.1 to 0.2 are for precision measurements, class 0.5 for kilowatt hour meters, class 3 for industrial measurements and class 5 for approximate measurements.

How To Lay A Garden Path Efficiently

No matter the amount of work put into a garden, it will not be evident if a proper garden path is not laid. There is indeed no essence of keeping a well-maintained yard if an attempt to get around the yard will amount to trampling on the plants that make the yard beautiful.

Garden paths have different styles and a person has to decide which of the styles they can easily set up and maintain putting the resources available to them into consideration. Garden paths are not only useful in marking the part of the garden that can be safely tread upon, it also gives the garden an additional aura of beauty and charm.

How to Choose the Perfect Garden Path

An important thing to put into consideration before choosing a garden path style is the purpose of the garden path. Some garden paths are to be utilized daily to move from one spot to another while some paths are just for aesthetics. The purpose will determine what level of durability is required from the garden path. Stone and brick paths are usually more durable than mulch or gravel paths.

Also, the time available to put the garden path in place goes a long way in determining what type of garden path to lay. Some garden paths, like the stepping stones path, take more time while some others, like the gravel path, take less time.

The resources available to an individual also determine the type of garden path to be put in place. Some garden paths require less expenses. An individual who has little to spare can stick to the gravel or mulch garden path while someone with enough resources can use stones and bricks for their garden path.

How to Construct a Garden Path

Gravel Path

garden-pathOne major reason why gravel paths are the easiest to construct is that they are not usually set deep. Digging is, therefore, easy as it is only for a few inches; to accommodate the pebbles. The base is usually lined with landscape fabric which is to ensure that weeds do not grow through the path over time. Because gravel is not static, it needs an edge to contain it and the deeper edge for gravel path is the galvanized steel although other things like bricks or cedar can also be used.

Step 1: The first thing is measuring and digging up the shape of the path. Remember that the digging will not be too deep, up to 4 inches and the width of the path is dependent on individual preference.

Step 2: The next thing to do is to form the trench. The spade that was used while digging will be used to straighten the sides of the trench and the bottom of the trench should be smoothened by a rake.

Step 3: Crushed stone is added to the trench and also compressed. Compression is made easier after making the stones moist. This will not only make the process faster and easier, it will help in controlling the dust.

Step 4: The landscape fabric is subsequently laid in the trench. The shiny side should be upward. Spikes or pins should be used to hold the fabric down.

Step 5: The edging is installed and tapped down. The edging can be made to go through the landscape fabric to make sure that the fabric is totally held down. After the edges have been installed and tapped down the back of the edges should be backfilled.

Step 6: The path should be filled with gravel. The gravel should be evened out with a rake to ensure that no part of the landscape fabric is visible. To maintain a gravel path, it should be periodically raked evenly and more gravel can be added if required.

Block Path

block-pathA Block path requires more effort and time than a gravel path. Basically, to construct a block path, most of the steps utilized to construct a gravel path will be employed. A Block path is, however, more durable than a gravel path. The only added work will be ensuring that the path is sloppy to ensure an uninterrupted flow of water.

Another difference is that the edging need not be galvanized steel. They are boards which can be nailed at the sides to wooden pegs that have been firmly rooted into the ground. A layer of gravel will be spread evenly into the path and it will be covered by a level of fine sand. The fine sand and gravel underneath will be fully compressed after which the blocks are systematically placed close to each other, on the gravel.

Mulch and Stone Path

Mulch paths are not only easy to make, they are also inexpensive although they may take more time because of the stepping stones that have to be carried. Two types of mulch are mostly commonly used; the cypress mulch which is lighter in color and the hardwood mulch which is darker in color.

The cypress mulch is used inside the path while the hardwood mulch is used outside the path to give the garden a beautiful contrasting look. Other important materials to be used are stepping stones and landscape edging kits (this does not require digging).The steps to be employed are;

Step 1: The stepping stones will be laid out in a way that each stone is at a comfortable distance from the other. This is to ensure that each step lands on a stone.

Step 2: Choose and measure the desired width of the path and place the landscaping edging kits at the measured edge.

Step 3: The landscaping edging kit is then pegged down. A hammer can be used to achieve this. The pegs should be placed at every 4 to 6 feet and particularly at the top of any curve.

Step 4: The mulch is then poured into the path. The mulch will be evened out by a rake. The mulch that is darker in color will also be poured outside the path and thereafter evened out.

Pallet wood path

For wet sites, a person can utilize a pallet wood path. A pallet wood path is not as difficult to construct as other garden paths because it doesn’t require digging at all even though it may require more money to purchase the pallet wood. It simply requires mapping out the path and leveling it. Pallet wood is subsequently arranged on the levelled soil.

Basic steps in laying any garden path

Even though there are different styles of garden paths with different laying procedures, these basic steps cut across all the styles.

  • Mapping

The first step for all garden path styles usually has to do with measuring and mapping out the path. The measuring tape is very useful at this stage.

  • Digging/ Leveling

Mapping is followed by digging if the garden path requires it or leveling the soil if the garden path does not require digging. The digger, shovel, and rake are very useful at this stage.

  • Edging

This is just to demarcate the garden path from the rest of the garden. It may be done with galvanized steel, wood, stone, landscape edging kit, blocks or any other thing that can make the path stand out from the rest of the garden.

  • Filling

This can either be by crushed stones, gravel or sand as the case may be. The rake is useful at this stage to even out the filling.

  • Covering

This is usually the final stage and it involves covering up the path with the desired cover which may be gravel, pebbles, blocks, stones, mulch, pallet wood, etc.

In the light of this, an individual can formulate a totally different garden path style based on the resources available to them. Laying such a garden path will not be difficult as long as the aforementioned basic steps are implemented.

In conclusion, apart from the numerous benefits that are attached to a garden for laying a garden path, it is also beneficial in many other ways to the individual. Laying a garden path can serve as a form of exercise ground to a person.  Buy your paving needs at Midland Stone, where they have a huge range of blocks and paving for garden paths.

Which is the Best PAT Tester?

There is no definitive answer to which is the best PAT tester, and with numerous models on the market, the bottom line is that you choose the PAT tester that best suits your needs. To help navigate the PAT testing equipment market, consider the following questions:
How often will you be PAT testing? Where? Will you test 110v and/or 240v equipment? How many appliances are you likely to test? What’s your budget range?


How often will you be PAT testing?

If your PAT testing activities are basic and few and far between (less than 500), then forking out for a top of the range bells and whistles model is probably not the best choice for you, however if you are undertaking regular PAT testing, it does makes sense to choose a reliable quality entry level product that covers your regular requirements. Over 500 tests? then a professional instrument should be considered, as the initial outlay is offset by its durability.

Where will you be PAT testing?

If you’re out on site carrying out regular PAT test’s then a sturdy robust reliable model is clearly an advantage, whereas if you’re more likely to be doing bench testing in the workshop then that may be a different matter.

Are you more likely to PAT test on 110v or 240v equipment?

Having 110v/240v PAT testing capability is clearly an advantage, but not all PAT testers have the capability to do both load tests, so if you need this feature, make sure your chosen tester has it before you buy!

How many appliances are you likely to test?

How many portable appliances you are likely to test will impact on your choice of instrument. If you’re responsible for multiple appliances over several sites, and your testing activities occur regularly, you may choose a PAT tester that can download test data via a USB port onto a computer database for ease of tracking. Similarly, models are available with software that will produce labels, certificates and all manner of information, as well as test limits and sequences that can be formatted to your specifications. Some testers have QWERTY keyboards which makes it easier to enter data into the test instrument, and if you’re doing a lot of testing at the same site a bar code scanning feature can be a great time saver too.


A top of the range PAT tester with all the features may cost you thousands, but there is no need to spend that much on an instrument for features you’ll never use. As with other electronic items, the cheapest is not always the best buy, reliability often coming second to price. So shop around, don’t assume your local electrical wholesaler has the best deal on PAT testers, check out what’s on line, check out the manufacturers sites, ask your mates in the trade.

Ok so with the above questions in mind, just what types/models of instrument are on the PAT tester market? 

Manufacturers like Megger, Martindale, Seaward and Kewtech are well established on the test instrument market and produce quality PAT testing equipment. There are a number of other manufacturers producing perfectly serviceable instruments to choose from too. Buy a test instrument within your budget range that covers your basic PAT testing requirements (Earth Resistance, Insulation Resistance, Earth Leakage /Touch Current, Load Test, RCD Trip Time) and if your budget allows for a more expensive model with more features, then there are plenty on the market to choose from.

Types of PAT Tester:

Pass Fail Testers

Steer clear from these. To do the PAT job properly you’ll need to interpret actual readings and these instruments don’t show them so you’ll still have to measure the earth continuity resistance value with another test instrument to meet the IET Code of Practice recommendations!

Manual PAT Testers

These PAT testers require the user to manually record test results and appliance details. Usually featuring separate tests for extension leads and appliance Classes 1 and 2, the pass limits are usually fixed so some manual interpretation of test results will be needed.

Downloadable PAT Testers

These PAT testers feature a much wider range of tests and data download capability i.e. appliance details and test results. Their range of test sequences and individual test capabilities make the test results easier to evaluate and the benefits of this type of tester are clear: time savings and data traceability of test results, however, they do come at an increased cost.

Battery Operated PAT Testers

The convenience of battery operation is offset by limited functionality. Such PAT testers cannot perform a load test, a high current earth test or measure earth leakage, however, some models do feature a 230v supply option which would allow such tests to be performed.

How Much Does A Home CCTV & Burglar Alarm Cost?

The simple answer is it all depends upon the size of your home and the type of system you wish to install.

Different Types of Systems


Home security systems can be either wireless, making it easier for the homeowner to install as they work using wifi and there are therefore no cables to be routed and hidden, or ‘hard wired’ meaning the components are connected by cables. ‘Hard wired’ systems may prove cheaper to purchase but they will need to be fitted by a qualified electrician, which in turn will mean paying labour costs.

Wireless systems can be easily deactivated and removed to a new property, another feature worth considering.

There are differences between burglar alarms and home security systems using CCTV, see more at Alert Watch; these are for surveillance purposes and allow the user to see who is approaching their home, often listen to what they are saying, and with certain types of systems record what the cameras are seeing. Burglar alarms set off an alarm that is triggered by invasive action after the alarm has been set, for example a window being broken or a locked door forced open.


New and complete wireless security systems with up to four cameras can be found online for between £500 to £1,000, with installation costs included. Many new systems are accessible remotely for additional peace of mind when away from home.

Another factor to consider is whether to buy new or ‘seller refurbished’ of which there are a number available through online retail outlets; these systems can be wireless, include two cctv cameras and motion sensors and can be found for just under £200. Additional components such as further cameras and sensors may be added provided the receiving equipment has the capacity to manage this, but this will mean making further purchases.

Wireless alarm systems can be found online from as little as £350 fully installed. This will be for a basic package but additional sensors can be added at extra cost.

Yale make a burglar alarm system for use with Android or iOS smartphones and a basic package consisting of one camera and one motion detector plus door sensors, siren, dummy siren and keypad and wifi control box can be purchased for under £390 online. As ever, additional components can be added at extra cost. This system is wireless and does not require a professional electrician to install it. Information can be accessed from your smartphone.

When looking online for local suppliers of alarm systems, check that the costs quoted are ‘one off’ costs and whether additional annual or even monthly fees are going to be incurred and whether or not you will be required to sign up to a contract, some of which can be for 24 months and can cost anything from £15 per month for external monitoring, yearly maintenance and inspection and other call outs. An alternative to this may be a ‘one off’ payment above the cost of the basic alarm system, with ‘pay as you go’ options on any call outs.

When considering any of the above options, take care to check whether a ‘police response’ notification comes at additional cost.

You will get what you pay for.

It is possible to acquire a basic cctv monitoring system for around £500 new and less than £200 ‘seller refurbished’. Such a system will allow you to monitor movement around the exterior of your property or even the interior as well if you add further cameras at additional cost.

A burglar alarm system can be purchased for £390 online and fitted by yourself.

Professionally fitted alarm systems can cost as little as £400, with some installers quoting less for the most basic of systems; expect to pay more for additional components such as sensors and cameras, however, and other devices, and again, watch out for contracts with monthly costs and additional fees for Police responses.

Deciding what to buy

Basically there are several questions you need to ask yourself:

• What is my overall budget? The more you spend the more devices and therefore the more protection you can purchase, together with versatility of application and access. This will be linked to the size and layout of your home.

• Do I want to fit the system myself? If you are technically minded and computer literate this can save you money and give added satisfaction.

• Do I want to have the peace of mind of being able to call on a professional company in case of breakdown or other issues? This will involve signing a contract and making monthly or annual payments.

• Do I want to have my alarm system established to initiate a response from the Police if activated? This again will involve additional costs.

Shop around

New and seller refurbished systems can be acquired for a few hundred pounds and less.

If you decide to go for a system that will be professionally fitted and maintained, look online for local providers; most will offer free quotes and it is a competitive market.

Why Instrument Calibration is Necessary

Calibration can be termed as evaluation and adjustment of an instrument with the aim of maintaining precision and accuracy of the measurement equipment. As such, proper calibrated instrument ensure people work in a safe environment and have access to valid data even for future use.

Purpose of Instrument Calibration

calibrationInstrument calibration allows users to eliminate or reduce chances of biased instrument readings along the range that the instrument is standardized with. This process also ensures there is consistency and continuity in values. Consider precision as defining the degree of repeated measurements to which same measurements are recorded with the same device under unchanged conditions. Therefore, it is important to note that reference standards should be used when selecting the precision test to be used or the range of interest. As for accuracy, which is the degree of closeness of recorded measurements in relation to the actual true value, there arises a functional relationship that establishes the reflected value with the standard value.

In most cases, instruments require correction for bias or when instruments act as surrogates. In the first scenario, the instrument is first set in the same units as the referencing standard. This is because the process aims at identifying and eliminating biases within the instrument relativity as defined by the unit of measurement. For instance, optical imaging systems used to measure the width of lines specifically on semiconductors use micrometers as their standard unit. However, these instruments are to be calibrated as the reference standards that the industry has laid out as the standard units for width lines in the industry.

When instruments act as surrogates, it means that the instrument uses a different standard unit other than the reference standard. As such, calibration could play a role in converting the instrument readings to the standard unit. For instance, a densitometer serves as a surrogate for measuring radiation dosage. Since the reference standards go by what a radiometry uses, the densitometer measurements are irradiated at particular dosage levels to ensure its measurements are in line with those of the radiometry. As such, when calibrating a densitometer, the calibrator considers the readings as per what the standard unit considers the optimum sterilization condition as required for medical devices.

Basic Correction of the Instrument for Bias

Calibration works the same way for instruments acting as surrogates as well as those needing correction from bias. As such, the basic steps for this process are:

• Selecting reference values within acceptable standard units with an aim of covering a range of interest.

• Carrying out measurements using the standard units on the instrument.

• Identifying the functional relationship between known values and actual reflected values keeping in mind the use of a calibration curve.

• Lastly, correcting the measurements by inversing the calibration curve.

It is important not to confuse a field check from calibration as some are in the habit of doing. A field check consists of two instruments reflecting the same reading. Nonetheless, these results do not necessarily dictate that the instruments are calibrated. For example, when a thermometer always reads 25 degrees higher, such an error is not eliminated by simply taking averages since the error is constant across the range of interest. However, one could determine its accuracy and fix it by sending it to a calibration laboratory. In line with that, it is always good to have more similar thermometers, which are used to make the same measurement. If the reflected results among the thermometers show a significant difference, then these thermometers are flagged for inconsistency and a test from the laboratory will correct things quite easily.

When Should Instruments be calibrated?

Consider major critical measurements a red flag to ensuring the instruments are calibrated before use. Additionally, it is important to calibrate these instruments even after use. This not only helps to ensure the data to be collected or already at hand is accurate, but it also means the instrument is in right condition even when it stayed long before use.

There are cases where the instrument falls or is repaired. In such events, consider calibrating the instrument before use. Accidents are a common way of throwing the instrument off balance, and it is important to do a calibration to ensure accuracy and precision are restored.

When observations appear questionable, consider sending the instrument for calibration. There are instruments that require certificates before use. Ensure these instruments are certified. Most manufacturers recommend an instrument to be calibrated within certain period. Always check the schedule for calibration to ensure the instruments are taken care of in good time.

Additional Importance

Assume that you are about to publish a paper, and once the paper is submitted and the peer review board realizes that your readings were wrong, that would adversely affect your reputation in the field and definitely decrease your chances of being a reliable source in the future. Always ensure your instruments are calibrated in time.

The Main Arc Flash Risks & Hazards

arc-underwearAn Arc Flash happens during a fault of a short circuit situation that passes through an arc gap. This perilous condition is linked to the release of energy caused by an electrical arc. An electrical arc, on the other hand, occurs when there is loss of insulation between two conductive items at ample potential (voltage). The short circuit power available near high power electrical equipment like service entrance switchgear or transformers is high similar to the energy connected with the electrical arc when a fault occurs. An Arc Flash can be formed through incidental contact which is undervalued for the available short-circuit current, tracking over insulated surfaces and corrosion or degradation of equipment.

hoodMany faults occur during manual operation or switchgear maintenance. Under such circumstances, not only are staff in front of the switchgear and accordingly likely to be deluged by the electrical arc but the fault is typically caused by activities carried out. Such operations include dropping a gadget on live bus bars or closing a circuit breaker under short circuit among others.

The occurrence of an Arc Flash can emit large quantities of deadly energy. The energy expelled by the arc as a result of a fault causes a rise in temperature and pressure in the nearby location. The arc brings about an ionization of the air and the arc flash temperatures become very high, hotter than the surface of the earth. This results in thermal and mechanical stress to adjacent equipment and creates the likelihood of severe injuries within the locality.

The faults that may happen in electrical switchgear are typically;
i. Phase-to-ground fault
ii. Phase-to-phase fault

It is uncommon for a three-phase fault to occur but remember that both phase-to-ground and phase-to-phase faults can quickly result in a three-phase fault. The two faults can be created by accidental contact of equipment or a person with live parts.

Arc Flash Risks and Hazards

The physical effects of an arc flash include:
i. Heating of materials coming into contact with the arc flash
ii. Pressure wave in the surrounding where the arc is created
iii. Possible hazardous sound and light

The main personnel hazards that may arise due to the release of energy created by an arc include:

i. Burns
The kind of temperature produced by the gases of an electrical arc and the emission of burning metal elements can cause severe burns. The heat causes severe burns in humans rapidly within the vicinity of the event. Flames can result in all kinds of burns even carbonization; the incandescent metal fragments can lead to third-degree burns. Flash temperatures liquefy metal parts like aluminum conductors, copper or steel equipment parts. Excessively heated steam results in burns similar to hot liquids and the blazing heat cause less severe burns.

ii. Potential Harmful Sound
The vaporized materials rapidly expand in volumes as it transforms state from solid to vapor generating explosive pressure and sound waves. The electrical arc is a real explosion, and its sound blast makes eardrums to break causing temporary or permanent hearing loss.

iii. Injuries as a Result of Emitted Objects
The electrical arc ejects molten metal or other loose objects that are sprayed by the explosion in the surrounding. Loose objects and metal debris can be deadly objects and can penetrate the cornea. The extent of the abrasions is dependent on the creatures and the kinetic energy of the materials. The area of the eye like the retina and cornea can sustain contusions to the mucosa due to the gases emitted by the arc and release of infrared and ultraviolet rays. The bright flash of the occurrence can cause temporary or permanent blindness. These impacts result in personnel lesions or even worse, death.

iv. Inhalation of Noxious Gases
The fumes created by combusted insulating objects and vaporized metals can be poisonous. The fumes produced are as a result of incomplete combustion and are formed by carbon compounds and other solid substances eliminated in the air.

Safety Standards

Arc Flash Hazards is a topic that is undergoing a lot of discussion and investigation in the current safety responsive environment. The essence of the standards is to offer an increased level of protection for electrical workers. There are particular approach boundaries tailored to protect staff while working on or near energized equipment. These limits are:
i. Flash Protection Boundary
ii. Limited Approach
iii. Restricted Approach
iv. Prohibited Approach

There are several ways to protect employees from the risk of electrical hazards. Employees should adhere to the Arc Flash Hazard Label by wearing proper personnel protective equipment (PPE); utilize insulated equipment among other safety-related precautions. This includes not operating on or near circuits unless you are a qualified worker. Other safety standards include the use of arc detection and reduction systems, IP codes and ways of separation, internal arc proof switchgear, and safe work practices.

How Long does a PAT Certificate Last?

Portable Appliance Testing is a the process in which electrical appliances are regularly and routinely checked to ensure their compliance with safety regulations. It is required by self-employed people, landlords and employers. Though no set rules are determining the frequency for PAT Testing, different appliances, conditions and circumstances may call for regular checks. It is only specific that all equipment and appliances be tested as regularly as possible to ensure they are in optimal working condition.


Guidelines for PAT Testing

There are guidelines and recommendations for the regularity of PAT Testing of different equipment and facilities, based on the risk levels and conditions to which the appliances and equipment are exposed. These guidelines and recommendations are explained briefly below:

In offices, hotels and shops, all stationery equipment, IT equipment that is classified as Class 1, must be checked every forty-eight (48)months. Portable equipment and partially movable equipment like extension leads should be monitored every twenty-four(24) months. All appliances that are hand-held must be checked every one year.

Industrial institutions and sites, including commercial kitchens, should have their hand held appliances and portable equipment checked every six months. This is in consideration of the intensity of working conditions that these appliances and equipment are exposed to.

All construction site equipment with a capacity of 110V should be checked every three months while in schools and other social places, all Class 1 equipment and appliances should be tested every twelve months, with Class 2 equipment and appliances tested every forty-eight months.

Equipment that is used more should be tested more regularly since the exposure to damage and malfunction is higher.

People using appliances should be sensitized to report any hitches as soon as they are noticed to create time for checks, thus avoiding major hazards.

PAT Testing is done using specific tools and by trained individuals.These tool kits range from beginner to advanced, and the prices vary too. The choice of tools and machines to use in PAT Testing will be determined by the simplicity or complexity of the appliance being tested, and also by the variety of the appliances being tested.

PAT Testing Certificates

PAT Testing certificates are issued to companies whose appliances have been tested and certified as compliant.The certificate indicates that the company’s appliances are fully tested and in compliance with the set safety standards, checked regularly and free from damage/risk.

PAT Testers use certificate templates to prepare certificates for compliant companies.The certificates are well detailed and include details of the specific appliances, the details of the test and the test report, which is the result showing any defects detected or noted in the appliance, and or the recommendations for repair or replacements. Appliances that fail this test should be repaired or summarily disposed of and replaced.

PAT Testing forms are issued only by qualified contractors who have been certified by the NICEIC/ECA. Persons performing PAT Testing and issuing certificates are certified as skilled and competent by the certifying body.

Importance of PAT Testing

PAT Testing is an important factor in ensuring the safety of workers at the workplace. In the UK, it is reported that an approximate of 30 industrial personnel deaths is a direct result of appliance malfunctions each year. The aim of PAT Testing is to help avoid these deaths and safety related incidents. Portable appliances that are connected to electricity including but not limited to printers, toasters, blenders, fridges, and ovens are responsible for twenty-five(25) percent of all workplace accidents in the UK each year.

Adhering to the Health and Safety Executive’s PAT Testing guidelines will help make a company a safer place for all personnel, as well as satisfying requirements set by insurance companies.

PAT Testing Technology

In this age of technological advancement, most PAT Tests now have computerised machines specially designed for them like Fluke and the Seaward Apollo 600 which can be seen here. These machines are briefly described below:

Pass/Fail Testers

Mainly designed for the in-house testing personnel, these are typically easy to use and cheaper as compared to other models. Some come fitted with a rechargeable battery while some are connected to the Mains and require AC power to operate. These simple machines indicate either Pass or Fail, with dedicated lights for each function. They also show polarity, insulation resistance and earth continuity.

Advanced PAT Testers

This is a category of testers that process and display more information than just pass and fail. The readings on these machines require analysis by a qualified technician. They are highly effective since they record information and test status of appliances, as well as having the capacity to interpret earth continuity resistance at different levels of precision, thus enabling the testing of a variety of sensitive devices.

It should be clearly termed as a benefit to companies institutions to comply with PAT Testing guidelines and regulations to ensure a safer, more conducive and efficient work environment for personnel.

Why Lockout Tagout is Important for Electrical Safety

Lockout/Tagout is defined as the placement of a lock or tag on an energy isolation device indicating that the device is not to be operated until the tag or lock has been removed. Lockout is a complete program used to control hazardous energy and preventing injuries in the workplace. It provides the much required visual caution when performing maintenance on the machinery, thus reducing the high risk of injuries.  Lockout Tag out (LOTO) program is important in the following ways:

1. Preventing Injuries at the work place

padlockWith the LOTO system in place, workers will take the precautionary measures when handling machines with the tag. By taking caution, workers will be able to reduce the exposure to injuries to themselves and their fellow workmates. The LOTO program is put in place to set the procedures to follow when a machine is in need of repair or just a routine maintenance. If these LOTO procedures are followed to the letter, the cases of injuries reported will be few and injuries will be less.

Image from Lockout Safety

2. Minimizes the risk of exposure to hazardous energy and electric shock.

With the LOTO program and set procedures, the handling of defective machinery will  cautionary. all machinery will be switched off and communication to all the other employees in advance. This will prevent the accidental switching on of the machines when being repaired, in turn reducing the emission of the hazardous energy which will put the lives of the employees at risk.

3. Save lives.

Some of these injuries  can prove to be fatal. This fatal can claim scores of employees lives in the long run. Without LOTO, employees are not able to take precaution when handling the machinery during repairs and maintenance. Many lives are lost because of neglect by organizations but with LOTO, many lives can be spared by proving the necessary caution.

4. Minimizes exposure to litigation.

lockout-kitBy minimizing the injuries in the workplace, the institution will reduce its exposure to court cases in which injured employees will sue the company for compensation due to the injuries gotten within the organization’s premises. If the organization is taken to court, it will incur so many charges in terms of legal fees and compensation for the injured employee. With a successful LOTO program, less injuries means less litigation for the organization preventing negative publicity for the organization.

Image from Lockout Safety

5. Instilling employees confidence and trust in the organization.

With LOTO in place, employees will have peace of mind knowing that they are working in safe environment hence they will put all their energy into their work. They will be focused on their duties hence the company will be effective due to the effective labor force. By creating a safe working environment, more employees would be willing to work for the organization thus increasing the efficiency of the company by decreasing the time needed to complete a certain task or assignment.

6. Increased Profits.

With increased efficiency from the employees, the company’s productivity increases as the employees will work more. This will in turn maximize the organizations profits greatly. This will be of benefit to both the organization and its employees. This will lead to the expansion of the company or organization thus increasing the employment opportunities to the many jobless youths. This is an indirect importance of the LOTO program. The company will also reduce costs on purchasing new machinery, because the LOTO program will ensure that the machinery is handled by the professionals thus reducing the chances of the machine breaking down. This will save the company a lot of money.

7. Recognition from the relevant bodies.

Organizations which have successfully implemented the LOTO program, receive the much required recognition and awards for having few or no injuries. This in turn reciprocates into positive publicity for the organization, instilling confidence on potential investors and clients willing to work with the organization. In some states, companies receive benefits and discounts on workers compensation if there are few accidents reported.

What Are Clamp Meters Used For?

Clamp meters are a versatile device that measures the current flowing through the conductor without coming in contact with it. It has two jaws, which open up and allow the operator to clamp the instrument around the electric cable or wire to measure the amperes flowing through it, in a safe manner. A digital clamp meter is generally used to measure Alternating Current (AC). It is easy to take measurements of alternating current with magnitude of 1000 Amps or more. This type of instrument has limitation when it comes to measuring very low AC current (in Milliamperes) and DC current.

fluke-clamp-meterThe clamp meter works on principle of conductance through inductance, which happens in transformer. The split ring or the jaw of the clamp meter, which is made up of Ferrite iron has a wire wound around it. This makes the jaws of clamp meter behave as one winding of transformer while the conductor cable around which, jaws are clamped becomes the secondary winding. This arrangement induces current in the clamp meter, which is measured and displayed on it LCD screen in an instant.

Advantages of Using Digital Clamp Meter

Measuring the amount of current running through an electrical conductor is all but essential to help guarantee the safety of the conductor and any related devices. There are several options to be considered when attempting this and a common choice is by employing the benefits of what is known as a current clamp meter. So, let us take a brief look at why this meter is an important tool and some of the common situations where it will be utilised.

A Brief Overview of a Clamp Meter

As the name denotes, a current clamp contains two “jaws” which open and close around an electrical conductor, you can see an example on this page. This meter will measure various attributes of the current contained within. The primary advantage of a current meter is that it is less “hands on” than a traditional multi-tester. That is, electrical power does not have to be shut off nor does the conductor have to be removed to ascertain the properties of the voltage within the wire.

Current meters can gauge and analyze a wide variety of metrics within a conductor. Some of the most common measurements will include:

  • Alternating current
  • Direct current
  • Resistance
  • Continuity Temperature (in some models)
  • Capacitance (in some models)

The Applications of a Clamp Meter

The main application of these meters is to provide simultaneous measurements during troubleshooting tasks where certain electrical equipment should not or cannot be turned off. Examples of this could be in a large industrial complex where a steady supply of power must be maintained to a ventilation system. Another instance may be a location such as a hospital where the main feeds into the complex need to be maintained operational at all times. Additionally, many electricians will normally carry two meters: one to measure the amount of current and another to determine the voltage within a conductor. A clamp meter can gauge both of these variables. Thus, they tend to be more user-friendly while offering the possibility of completing a job faster.

Clamp meters are also widely employed to detect what is known as an “inrush” in electrical terminology. Certain machines may require a massive initial amount of electricity to start up. This can often be the case in industrial environments. This initial “burst” is called an inrush. While the machine may require this amount of current, it must be determined that the surge protectors and the line itself have the capacity to handle such power. Clamp meters can track this load in real-time and will provide a very accurate readout of the characteristics involved in this phenomenon.

Another area where clamp meters are employed is when one needs to measure extremely high voltages. As the current, amperes and voltage can all be determined without physically exposing the bare conductor, clamp meters are often the safest and most logical option. Nonetheless, an increasing number of electricians are beginning to use clamp meters for domestic purposes as well.

As the popularity and versatility of clamp meters continues to increase, it can only be expected that they will continue to play a pivotal role in the electrical and industrial trades into the future.

These devices can be used as attachments to multimeters and as a stand alone device. It is among the most easy to use tool that is quite indispensable while working with high power circuits.

However, there may be irregularities in the flow of power supply. Power fluctuation and failure are some of the most common issues which can lead to massive damages of machineries and loss of productivity. Therefore, it is essential to monitor the flow of current regularly with the help of a clamp meter or current meter.

These devices were found in analog models in the early days. But today the online stores are flooded with a huge variety of meters with digital displays. These modern devices offer accurate outputs and easier analysis of electrical current. These devices are among the most popular tools used by electricians due to its beneficial features.

First match the setting of the device to the current of the circuit to be measured by turning on the dial on the meter. Make a choice between AC and DC. Most of the household wirings include AC power.

The meter should be set to an expected range close to the circuit which is being measured. The power current is often measured in amps and milliamps.

The clamps should be connected around the wires to obtain an accurate measurement. It is important to measure only a single conductor at a time so that accurate readings can be obtained. Pass small amounts of power consistently. Gradually pass large amounts of current to analyze the errors in connection or the equipment. Read the display to obtain accurate measurements.

The traditional Clamp meter functions, if placed around single conductor. However if it is clamped around 2 or more cables then it will not display any reading because the individual magnetic fields of the cables, cancel each other. However new type of clamp meters is available in the market that has group of sensors coil placed around the jaws of the clamp. Such a digital clamp meter can be clamped around a bundle of 2 or three cables to take the reading of combined load flowing through the bunch. The clamp meter prices vary according to the models available in the market and it is to the best interest of the users to ensure that model they select meets all their requirements.

What does a Thermal Imaging Camera do?

camera-thermalSimply put a thermal image camera is a device that enables the cameras user to see things in the dark. This is possible because every object and creature radiate heat. The thermal image camera picks up this heat as infrared radiation and it shows up on the cameras screen. The warmer the object the sharper it will show up.

Without going into too much technical detail, a thermal imaging camera consists of five basic parts. A signal processor, a detector, an amplifier, an optic system and finally a display, using these five components makes the camera able to display different colours to show the variations of temperature when it is pointed at different objects. Warm or hot colours will show up against cooler objects.

It is not night vision

Thermal imaging must not be confused with night vision visual aids or ir windows. Night vision instruments work in environments where there is a small amount of light undetectable to the human eye, but they cannot work in complete darkness. Thermal imagers can work it complete darkness as they only rely on the heat radiated from the objects they are looking at.


The origins of the thermal image camera go back to the early 1950s when it was developed as an aid to troops fighting in the Korean War. However like many other inventions originally developed for military purposes the civilian world soon adapted it for its own use.

Rescuing or catching people

A thermal image camera can be used to locate heat in various objects. As it is used in the absence of light, it is extremely effective in tracing people in the dark. These may be fugitives trying to avoid capture, or people who may be lost and in distress or danger.
Great strides have been made using thermal imaging cameras in situations where people have been trapped in collapsed buildings caused by explosions or earthquakes. They played a significant role in the locating and rescuing of survivors after the attack on the twin towers.

The Firefighting service

Since then firefighters over the world have invested in thermal imaging cameras to help them locate people in danger. There are two kinds of thermal imaging cameras used by firefighters. One is a handheld version and requires two hands to direct it onto its target. To alleviate this problem, some cameras have been mounted onto their helmets. This releases their hands for important rescue work. The ability of thermal imaging to see through the smoke and identify people makes it a valuable asset in saving lives.

The Construction Industry

The construction industry uses the camera when looking for areas of overheating or leaks of heat coming from faulty thermal insulations. Thermal imaging cameras are a vital component in this field where there is evidence of heat loss and air exchange. As the loss of heat is responsible for nearly half of the consumption of energy in buildings the thermal imaging camera makes it possible for the leaks to be identified by, detecting the places where heat is escaping that would be impossible to be seen by the naked eye. The cause of most of the heat loss and poor exchange is usually inferior construction and design and without building inspectors having access to thermal imaging cameras, it would be impossible for them to make thorough inspections to resolve the problems.

The Medical Profession

The medical profession uses thermal imaging to trace any areas on the human body giving out excess heat that may indicate a fever or some other ailment. Thermal imaging has become a way for doctors and other medical practitioners to discover problems in the human body without resorting to invasive techniques that may cause a patient some measure of distress or discomfort.

The thermal image camera has made it possible for the medical profession to identify danger spots by the presence of abnormally hot or cold spots in the body. Health problems such as skin complaints, arthritis, and other health problems can be discovered before they show themselves to the naked eye.


Although the thermal camera has made it possible for many problems to be located in situations mentioned above it is not an infallible instrument that can solve all problems.
It cannot be used to see through glass, as the heat will be reflected off the shiny surface of the glass. It cannot be used in rain or thick mist and fog, as the droplets of moisture will deflect the heat. It is not able to see through solid objects or clothing. The thermal image camera is undoubtedly an excellent instrument to help solve many problems, but it should not be used as the only solution to problems and should be used in conjunction with other instruments and methods to come to a final conclusion.