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Do You Need To Be A Registered Electrician To Test and Tag?

A post about an upcoming Test and Tag Competency event on our Metrotest Facebook page motivated one electrician to call us “Shysters” and less publishable names. He went so far as to do this publicly on our page and named us on his. To add insult to injury, he also left us a bad public review.

But why?

With the above in mind, as a business we could respond in several ways. We could retaliate and also leave a bad review on his page or possibly respond harshly. Whether these options would be the right thing to do is clear, unlike this individual we don’t throw our toys out of the cot.

We at Metrotest believe that professionalism outweighs an emotional reaction and as such, we want to take this as an opportunity to respond constructively and go through some details as to what may have led to the above events.

Every business, at some time or another, gets a bad review or ‘one-star rating’ – it’s nothing new. Sometimes things go wrong and for those born last century, as LV Martin used to say, ‘it’s the putting right that matters.

Constructive criticism only leads to improvement. It helps us identify weakness and encourages us to be better at what we do. We welcome it.  When it’s not constructive, such as in the case of Mr X, the public notices and it puts them in a bad light.

Here’s some thoughts on why this happened:

  • Mr X sees our Competent Person Training taking business off them and being a threat.
  • Mr X does not believe that anyone except a trained electrician can test and tag properly.
  • He may believe that anything ‘electrical’ in a business environment is, or should be, what is termed a ‘prescribed’ activity meaning that an EWRB Electrical Registration and Current Practicing Licence is required.

If this was the case, then why is the electrical board also handing out limited electrical tickets to related trades such as plumbers and within the appliance & IT industries?

Should Mr X feel upset, or should he view companies such as Metrotest as a support system to the electrical industry?

Here are some examples:

  • A properly trained and supported ‘Competent Person’ with a Portable Appliance Tester can not only test correctly and safely, but will sometimes test better than an electrician who does not have the correct equipment and does not know what is required to test to the Standard AS/NZS3760 , AS/NZS3012 and numerous other standards.
  • Qualification may give entitlement to do something, but without competency, safety will be jeopardised regardless of who’s doing the testing. By no means are we suggesting that registered electricians are not competent, but all know that the more you do one particular thing the better you are at it. Testing for electrical safety is all that Metrotest does.
  • Many electricians welcome our services. Whilst they focus on bigger margin jobs, they employ us to do the day to day testing. The time factor alone for them to keep up to date with technology and standards plus doing “smallish” jobs all across town saves them big money every year. In many instances our services are marked up to their clients as well.

Metrotest is your Specialist in Testing and Tagging

Metrotest has electrically qualified and trained individuals, some with current Practicing Licences, some without (as they are not doing a ‘prescribed’ activity).

Metrotest train electrical apprentices and will continue to do so. Metrotest also offer EWRB refresher courses for relative industries seeking to renew their Practicing Licences. We have both trained, competent people and EWRB registered people working for us in our own Test and Tag service since 1998 – that’s over 21 years.

We have two fully qualified staff running our Test Instrument Calibration and Repair Lab. Our own PAT testers are calibrated at least every 6 months, these being the most advanced SAFEFY testing PATs on the world market.  Not to mention that we are also involved in the design and build process.

For those who can test their own equipment this often works out much cheaper than the hourly rate an electrician may charge, especially if you only have a few items.  Also, it can be more convenient as you can tailor the testing around downtime or when it works best for you.

One last thought. In many businesses new items coming into the workplace can be a real problem as in NZ these should not be used until they have been tested and tagged. Calling a company in to test one or a few items will be expensive and likely a logistical nightmare. This problem is compounded if you’re in a remote location, have restricted security or very high security access areas.

If you would like to know more about testing and tagging your portable electrical equipment, then please give our friendly team a call on 0800 638 768.

Happy testing.

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Earth Leakage Testing

Appliance testing is becoming a common practice in New Zealand. Businesses and companies usually do it to ensure electrical equipment and portable appliances in the workplace are safe to use and complies with electrical safety regulations and standards.

Tests that are typically done include a visual inspection, earth bond or continuity test and insulation resistance test. In other cases, an operations test and an earth leakage test is performed to gain further information.

What is earth leakage?

To put simply, earth leakage is the current that leaks from a circuit to the ground. It usually flows through the protective ground conductor via the insulation and the filters protecting electronic equipment.

In any electrical installation, some leakage current is normal. It becomes a problem when the leakage current causes unnecessary and intermittent tripping (typically on circuits protected by Ground Fault Current Interrupters or GFCIs).

Ideally, electrical installations must be properly grounded so the current leakage would flow through the ground connection and into the grounding rod that connects the equipment to the earth. This provides protection against a shock hazard should an insulation fault occur. If the ground is incompetent or disrupted, an insulation failure could cause a rise in voltage on accessible conductive parts which can cause electric shock when touched. Even when there is no insulation failure, current leaking through the grounding rod still poses a threat of electric shock to anyone getting in contact with the ungrounded system and ground at the same time.

Causes of earth leakage

The most common cause of leakage current is inadequacy in the materials used to build elements like the semiconductors and capacitors. In some installations, longer conductors cause more current to leak due to the higher capacitance.

Old or damaged insulation can be another cause. If the insulation is in good condition, very little current should leak; otherwise, its electrical resistance is compromised which allows substantial current to flow.

The purpose of an earth leakage test is to measure the current leakage and recognising the cause. It essentially determines the amount of current that will pass through a person when that person touches an electrical device, thereby checking potential safety risks.

How is earth leakage testing done?

At Metrotest, we use portable appliance testing (PAT) devices to measure current leakage on any electrical installation or equipment. The objective of the test is to measure the currents flowing through the protective conductor or the metallic parts of the earth.

The test is usually performed when the equipment under test is running in its normal operating mode. Appliances with different work settings, such as a hair dryer, are often set to their highest setting during the test. If there is doubt an insulation test could damage the appliance being tested, an earth leakage test is preferable.

There are various earth leakage tests that can be performed depending on the asset type and classification:

  • Differential earth leakage test (IDIFF) – This test is usually done when the asset being tested is safe to run. It measures the difference in current flowing between the live and neutral conductors, which is displayed as the leakage current. The measured value is then adjusted to reflect the worst leakage current at the higher operating voltage limit.
  • Touch Current Test (IF) – This test applies to Class II items. Where there is no existing earth return path, one is created with the bond lead to simulate the equipment being held in the hand. Once the current leakage is measured, the value is adjusted to reflect the worst leakage current at the top operating voltage limit.
  • Substitute Leakage Test (IPE) – This test is done in case the asset is not safe to run during testing, such as a power cutter or electric drill. It measures the current leakage in the earth conductor using a low AC voltage (typically 40Vac), so as to reduce the risk of an electric shock. The low voltage also prevents the instrument from powering on during the test, which would otherwise be dangerous to the operator. The test does not require a supply voltage, hence the socket is optional. The measured value is adjusted to show the worst current leakage at the upper operating voltage limit.

Clamp meters are usually used to measure leakage current. However, this can also be done using a PAT tester. Metrotest has a range of PAT machines that have inbuilt capability to test earth leakage, along with insulation, operation, earth bond and flash tests. This is why they are preferable in appliance testing.

Here are some of the PATs we highly recommend:

  • Sonel Metro EasiPAT – Battery and mains operated (for powered up leakage testing), this testing instrument can measure insulation, polarity, residual current and earth leakage (200mA, 10A). Its LCD display has a Pass/Fail indicator. Has flashing warning lights when used for powered-up testing to provide extra safety for the operator.
  • Megger 150R – Tests single-phase appliances up to 10A. Capable of earth testing (200mA), insulation testing (250/500V), mains powered leakage test (230V), and lead testing.
  • Metro 6201A – An entry-level PAT for low-volume applications. This device can test single phase appliances up to 10A and perform earth test (200mA); insulation test (250/500V), mains powered leakage test (230V), and lead testing.
  • Metro iPAT SupaPAT – A complete testing package that is so easy to use. It includes the Sonel Metro iPAT standard set, plus thermal transfer printer, scanner and comprehensive software.

Why perform an earth leakage test?

As mentioned earlier, an earth leakage test can take the place of an insulation test under certain circumstances. For example, some appliances are not “completely on” unless they are actually operating, faults may not be detected by a normal insulation test but a leakage test can. Or if an insulation test gives questionable results, a leakage test provides a satisfactory means of checking for faults.

Since the test involves operating an appliance at full mains voltage, it can be problematic and even dangerous. Earth leakage test is best done by professionals who will take every single precaution to prevent any hazards. That being said, it’s important to hire an operator who is experienced enough in appliance testing. Here’s why: Some PAT testers may give an incorrect ‘FAIL’ indication which can result in assets being taken out of use unnecessarily. An experienced operator would know better.

To learn more about earth leakage testing, get in touch with our test and tag specialists!

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What Is a Residual Current Device?


A residual-current device (RCD) or residual-current circuit breaker (RCCB) is a device that quickly breaks an electrical circuit to prevent grave harm from an ongoing electric shock.

An RCD is designed to automatically and quickly disconnect a circuit as soon as it detects that the electric current is not balanced between the supply and return conductors of a circuit.

This is designed to prevent injury although this may still happen sometimes. For instance, a man falls after receiving an electric shock. Another instance is if the person touches both conductors at the same time.

How It Works

These electrical wiring devices are designed to quickly and automatically disconnect a circuit when it detects that the electric current is not balanced between the supply and return conductors of a circuit. Any difference between the currents in these conductors indicates leakage current, which presents a shock hazard.

Current of around 30 mA (0.030 amperes) through the human body is potentially sufficient to cause cardiac arrest or serious harm if it persists for more than a small fraction of a second. RCDs are designed to disconnect the conducting wires (“trip”) quickly enough to prevent serious injury.

RCDs are testable and resettable devices. A test button safely creates a small leakage condition, and a reset button reconnects the conductors after a fault condition has been cleared.

Some RCDs disconnect both the energized and return conductors upon a fault (double pole), while a single pole RCD only disconnects the energized conductor. If the fault has left the return wire “floating” or not at its expected ground potential for any reason, then a single-pole RCD will leave this conductor still connected to the circuit when it detects the fault.

This is a device for human safety rather than solely protecting computer equipment and its function is to minimize the possibly of injury through electric shock. An RCD works by detecting if electricity is “leaking” from a circuit and if so it breaks the circuit.

Most RDCs are combined with a circuit breaker and so will protect equipment in the case of an overload.

How to Test the RCD

Typically, RCDs can be tested by pressing a testing button with should cause the device to operate as if a dangerous leakage had occurred. If the device operates properly, it can be used in a live environment and will perform its function. RCDs should be checked on a regular basis to make sure that they are still functioning properly.

SafeWorkNSW Code of Practice

There are government regulations that cover the use of RCDs. You need to familiarize yourself with your local government’s policy.

SafeWork NSW has prepared a code of practice that includes the use of RCDs. The managing electrical risks at the workplace code of practice provides more information about electrical work and risk controls.

According to their report:

The risk of electric shock often results from people making contact with unprotected energized parts of electrical equipment and earth. Contact with energized parts may occur by touching:

  • bare conductors
  • internal parts of electrical equipment
  • external parts of electrical equipment that have become energised because of an internal fault
  • metallic or other conductive equipment that has inadvertently become live.

Contact with earth occurs through normal body contact with the ground or earthed metal parts.

Serious injuries and fatalities may be prevented by the use of properly installed and maintained RCDs, commonly referred to as ‘safety switches’. An RCD is an electrical safety device designed to immediately switch off the supply of electricity when electricity ‘leaking’ to earth is detected at harmful levels. RCDs offer high levels of personal protection from electric shock.

RCDs work by continuously comparing the current flow in both the active (supply) and neutral (return) conductors of an electrical circuit. If the current flow becomes sufficiently unbalanced, some of the current in the active conductoris not returning through the neutral conductor and is leaking to earth. RCDs are designed to quickly disconnect theelectricity supply when they sense harmful leakage, typically 30 milliamps or less. This ensures an electrical leak isdetected and the electricity supply is disconnected before it can cause serious injury or damage.

While RCDs significantly reduce the risk of electric shock they do not provide protection in all circumstances.

For example, an RCD will not trigger off electricity supply if a person contacts both active and neutral conductorswhile handling faulty plugs or electrical equipment and electricity flows through the person’s body, unless there is also a current flow to earth.


Using an RCD will help prevent electric shock that’s why it’s vital to your personnel’s safety. Choosing the right RCD for your business is important that’s why you need to check the right places online. Search for Residual Current Devices here and find the perfect RCD for your needs.

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Review of the EasiPAT

Portable Appliance Testing is quickly gaining popularity these days. Law does not require PAT Testing but employers – including self-employed people – must ensure the safety and proper maintenance of electrical equipment being used in their business or premises.

What Is Portable Appliance Testing?

Portable Appliance Testing (PAT) is widely used in the United Kingdom, the Republic of Ireland, New Zealand, and Australia. PAT is the process of routinely checking electrical appliances for safety.

PAT Testing involves a visual inspection of the equipment and any flexible cables to see if they are in good condition. It also allows for the verification of grounding continuity and testing the soundness of insulation between the current carrying parts and any exposed metal that it may touch. The test results will differ depending on the category of equipment that you are testing.

Sonel Metro EasiPAT Portable Appliance Tester

The Sonel Metro EasiPAT Portable Appliance Tester packs a big punch in a small package. This amazing little (PAT) fully functioned Portable Appliance Tester is the next step in do-it-yourself (DIY) testing.

The unit includes:

  • PRCD (portable Residual Current Device) testing
  • Battery & mains operated (requires mains for powered up leakage testing)
  • Powered up leakage testing
  • Insulation testing
  • Polarity testing
  • Earth Test: 200mA, 10A
  • Flashing warning lights when used for powered up testing-providing extra safety for the operator
  • 1 Push test selection
  • Bright Pass/Fail Indicator
  • Light up LCD display
  • Direct Wi-Fi Capable
  • Great carry bag with room for all your accessories and mini thermal transfer printer (Tough Tags)

Basic Limited Memory Capability

The tester has a built in a basic memory recall, which can be downloaded with Sonel Pats Reader and is able to do basic printing. A future App is planned for development.

Portable Residual Current Device Testing

Residual Current Device testing ensures that your RCD will operate quickly in the event of an electrical incident. Also known as safety switch testing, RCD testing enables your RCD to function well as it is designed to trip or turn off all the power going to that circuit. Portable RCD testing is one of the many features of the EasiPAT that ensures safety for your equipment.

Powered Up Leakage Testing

Leakage current testing checks the current that streams from either DC or AC circuit in an equipment to the ground or framework and can be from the output or input. The leakage current in an equipment flows when an unintentional electrical connection occurs between the ground and an energized part or conductor.

Insulation Testing

Insulation testing checks low voltage circuit breakers to ensure acceptable amounts of insulation resistance between phases and from phase to ground. The EasiPAT is used to apply an overvoltage to test the integrity of the insulation.

Polarity Testing

Polarity testing is used to check the right connection of the line and neutral conductors. In electrical terms, polarity refers to the negative or positive conductors within a dc circuit or to the line and neutral conductor within an ac circuit.

My Review of the Sonel Metro EasiPAT Portable Appliance Tester

At this point, I’d like to share my personal review of this amazing product.

The Sonel Metro EasiPAT Portable Appliance Tester is a great instrument for testing the safety and proper maintenance of all of my electric appliances. It’s lightweight and easy to use. I am able to test my equipment and appliances in the most convenient and comfortable way possible. No bulky machine to wield, just this powerful portable machine that lets me test quickly and efficiently.

The EasiPAT is reasonably priced and is a great value for money. It’s optimized for efficiency and is in stellar condition. It’s a high quality machine that’s sturdy yet economical. I love what the EasiPAT can do for me.

I am so happy I purchased the EasiPAT as it has given me convenience and safety in such an affordable package. Looking with long-term use in mind, I am able to get a significant return of investment for my installment in buying the EasiPAT.

When Do I Use my EasiPAT

I use the EasiPAT to test my appliances or equipment for safety and maintenance. Any appliance with a plug that must be connected to a wall socket needs to be PAT tested. This includes PCs, monitors, printers, electric drills, kettles, microwave, and other appliances that I use regularly. It also works for vending machines, photocopiers, and other appliances or equipment that you may have in your business or home. You will surely love this amazing machine.

Now that you know what the EasiPAT can do for you, go ahead and buy one for yourself. You will surely enjoy this handy new gadget that allows you to sleep secure in the knowledge that your appliances and equipment are safe. I hope you like your new EasiPAT as much as I do.

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In-house DIY Test And Tag – The Good, Bad And Ugly!

Can DIY Test and Tag really work?  The simple answer is yes, however there are 3 essentials to success:

  1. Training

This is essential and needs to incorporate easily accessed on-going support.  It is very interesting how so many new people have entered the training market claiming to provide training with full back up and support.  They obviously know this is what people want; so they state that they provide it – simple marketing really isn’t it!  This statement, however, needs further examination to find out who will be providing the training and importantly the on-going support available.

It is easy to say, ‘training run by an expert, fully qualified’. We reckon teaching what you do works the best and therefore all our trainers and support people can do the job – many with years of hands on test and tagging experience.  Nothing beats ‘real’ experience.  We’re not marketing gurus, but when it comes to test and tag we’re the experts – second to none!  This is because Metrotest is the only established nationwide testing company that is involved in all aspects of the industry.  Next year is our 20th year!

When you need ‘technical how to’ support we’re here too.  As I said before we do it and our ‘people’ not ‘person’ are available to help you.  You won’t get ‘sorry they’re on holiday ring next week’.  Good training and support are essential ingredients.

  1. Backup Plan

People, including all our staff, get sick, go on holidays, leave to work elsewhere or just get too busy in their core job requirements and this needs to be considered when planning in-house test and tag.  What happens if you get behind?  You need to have a contingency plan.  Metrotest can offer to our clients, who have our systems, a solution because we operate a nationwide test and tag company so we can seamlessly, in the right situation, ‘pick up the slack’, catch you up and then leave you to carry on. The only additional cost is our charge for testing. This program is called ‘Tandem Tag’ and has worked well for many of our clients.

  1. The Testing System

The last item you need, apart from the time, is the PAT Tester, or a ‘Pat testing System’.  What you need here is going to depend on how much testing you need to do (and how frequently you need to be testing), along with the requirements of what you need to test.  If you only want to test computers, then you would not be testing any 3-phase equipment and therefore do not need a PAT which will do this.  One size does not fit all and believe it or not small and portable, when put in a pelican style case, can become big and heavy very quickly!  If you are only testing a couple of hundred items per year the ‘tag printing’ option is not a biggy, but if you are into the thousand or so, then it is likely essential and probably an overall cheaper option.  If the capex does not allow for a printing option, then split the system and purchase the printing side later.  Obviously to do this you will need a compatible tester.

The most advanced system (and mid-priced) on the market today is our MetroIPAT and this is the system we use ourselves everywhere.

At first sight it may seem big – but it is actually a much smaller, lighter system than for example the Metrel Delta PAT which when in its case with printer and everything is bigger and heavier!  The MetroIPAT can test single and 3 phase items and has many advantages including double tagging and multiple coloured different sized tags, you can even make up your own test codes for non-electrical equipment eg ladders and have a tough tag printed out to put on them.  These are abilities that you will not find on any other PAT testing system.

The real advantage to the MetroIPAT system is the time saved, so you are less likely to need our ‘tandem tag’ service.  It can also test the protective earth at up to 25,000 milliamps where as most of its competitors can only test at 200 milliamps.  The ‘pushy salesman’ may tell you that this is not necessary – if you are not convinced that this is what you should be buying then read our Blog ‘Just Compliant or Really Safe’ – we all want a life jacket that saves our lives!

A new system coming to the market that is small and unique in many ways is the METRO EasiPAT 10, and it has ‘real safety testing’ and can use a small printer so the whole system is very compact and entry level pricing.

Summing up, you need real training and support, a back up plan for when you get behind and lastly the right test equipment (PAT system).  I think and always tell people to do one of our training courses first; then choose the test equipment after comparing options.  So often people do the opposite and end up with a dud tester or system which just makes life hard and often does not even test properly!

The last thing I’ll say about DIY or in-house test and tag is that it encourages/gets the staff buying in to electrical safety.  They take ownership of electrical safety and become much more aware of the dangers surrounding electricity and the use of electrical appliances; which is obviously a good thing.


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Just Compliant or Really Safe?

‘Compliance Testing’ or ‘Really Safe Testing’ – it’s your choice!

This may sound funny in a test and tag article, but I want you to think for a moment. You and your family are going boating, dad weighs 91kg, mum 58kg and 2 children 35kg and 28kg. Before jumping on to the boat you decide to test the life jackets, however you can only find a 30kg weight handy and decide to attach this to each life jacket and place them in the water to see if they float. If it floats will everyone wearing them be safe? Unless you are the person weighing 28kgs I wouldn’t be confident that this would be the case! Obviously, the testing weight should match up with the rated weight for the life jacket!

Let’s go back to electrical testing where we started. The two main tests that will normally be done on all Class I earthed equipment will be an earth test and an insulation resistance test. These tests are there to prove that the earth and insulation resistance is suitable and safe and this is done by measuring the resistance.

Insulation resistance tests are normally performed on appliances at 500 Volt (normal operating voltage is 240V, so testing is done at twice this). This is done as you want to stress test the equipment; effectively making sure electricity isn’t going to easily ‘leak’ out of it.  By testing it at twice the normal operating voltage we know, in its normal operation, if it passes the test the user should be safe. Obviously if we tested it at say 100V this would be like testing all life jackets at 30kg – it would prove nothing!

Now we’ll look at the protective earth test. First let’s explain why Class I (earthed appliances) have this protective earth. Electricity normally wants to find the easiest way of getting to the ground, i.e. the earth, the dirt etc we all stand on. The insulation of equipment prevents electricity leaking out of the outside case of the appliance.  If this insulation fails for any reason and there isn’t a good or real earth on the equipment, someone touching this may receive an electric shock which could be fatal. Therefore Class I equipment is always designed to have a protective earth which in the above situation will transport the electricity back to the ground preventing you from getting an electric shock.

When we tested the appliance’s insulation we tested it at twice its normal operating voltage. This time we are more concerned with how much actual electrical current can flow in the protective earth conductor. In a fault situation this can easily exceed 10 Amps (10,000 milliamps) so logically we want to simulate a test that proves, as above the life jacket floats, in this case that the protective earth will save the operator. The best and logical testing practice is surely, where appropriate, to test Class I items at a level that proves the earth will work when required, thus ensuring people remain safe!

What I’m now about to say may horrify many and probably should – most tests are done on the protective earth with a test current of 200milliamps (0.2 Amp) when a normal appliance can operate at 10 Amps (10,000 milliamps) – so why test it at 200 milliamps? Is it a worthwhile test? – you decide. So why do this test at 200 milliamps? Simply put, most testing equipment, even the most expensive ones, don’t often have this ability, but obviously it should. We, as a company design, supply and use test equipment that can and does real testing.

You may be thinking that testing for safety may cost more; the answer is no, it definitely shouldn’t.