Author: Metrotest

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Electrical Test Equipment Calibration: Why Is It Important?

Electrical calibration, in a nutshell, is a process of verifying an instrument’s accuracy. By default, every instrument that leaves the manufacturing plant is calibrated and certified based on recognised standards.

So why the need to calibrate, you might ask?

As with most devices, the components in your electrical testing instrument may shift over time. The shift may be small and insignificant, but in some cases it may cause a slight difference in measurement. The components are more likely to shift or get damaged if your instrument was accidentally dropped or hit against a hard surface. Your instrument might still work after such events, but you can’t be sure that it will still give you precise results. Calibrating your device gives you quantifiable confidence in its measurement accuracy and performance.

Calibration is especially important in cases where you are working with tight tolerances wherein proper operation of safety systems and processes requires accurate measurement. For instance, when testing Class II appliances where you’re working with small values, a minute discrepancy in the results could pass an item that should be failing, and vice versa. Or when you are trending data, and the meters you use for the same test produce different results. As far as electrical safety goes, using a less accurate electrical test instrument presents a number of risks and legal repercussions.

Electrical calibration

Technically speaking, electrical calibration is a process of verifying and/or adjusting the performance of any instrument used to test or measure electrical parameters (i.e. voltage, current, resistance, etc.).

Some people mistakenly call two meters “calibrated” if they both give the same reading during a field comparison check. But this does not necessarily prove that the two meters are accurate – they could both be “out of cal” condition by the same amount. A simple field check does not reveal the real condition of your electrical testing device. There must be a known standard to which the instrument is tested.

You can send your electrical test equipment to an accredited metrology lab or calibration specialist like Metrotest, who will check your testing equipment’s performance and key properties using precision devices that are at least 10 times more accurate than the unit under test (UUT).

Sending your device for calibration essentially means that you are authorizing the calibration house to carry out repairs or correction to bring the device back to “in cal” condition.

You’ll receive a report showing how your instrument compares to recognized standards, what errors were found and what corrections were done.

Calibration procedures

Calibrating your test instrument is a given, so the real question here is how often you should calibrate your tools. This will depend on the brand you’re using and how well the device is handled.

Sonel

For new devices with calibration certificate, Sonel recommends the next metrological inspection within 13 months from the purchase date, and not later than 19 months from the manufacturing date. Pursuant to standard EN ISO 10012-2003, a 13-months interval for testing must be observed.

Sonel calibration includes voltage, current and resistance calibration for instruments used for electrical and non-electrical measurements, including:

  • Electrical safety meters
  • Multimeters
  • Meters for electrical protective measurements: earthing resistances, insulation resistance, impedance and resistance of short-circuit loops, RCD parameters, etc.
  • Meters for measuring low resistance values
  • Power quality anlysers

Metrel

With the exception of digital mutimeters, current clamps and voltage testers, every Metrel device gets an ISO certificate when it leaves the production floor. Metrel’s default calibration includes installation testers (e.g. Eurotest, Instaltest, Insulation test), test equipme

nt (e.g. Clampmeters, Resistors, Multimeters), safety appliance testers (e.g. PAT, CE Multitester), and test equipment for environmental conditions (e.g FonS, Multinorm).

Calibration services will include adjustment, that is, bringing the instrument into a state of performance that is suitable for its use. All procedures are written a guarantee of reliability and repeatability of measurements. Metrel does not accept calibration request from end users, so you’ll need to send your device to an accredited metrology lab.

Megger

 

Megger tester calibration includes resistance function verification and voltage function verification. The procedure measures a resistance by generating a voltage. The value of resistance is computed using Ohms Law: V=IR. Megger has its own calibration box which is used to provide an analog resistance for the unit under test (UUT). The resistance output and voltage display of the calibration box is compared to that of the UUT’s.

Calibration can also be done using a Fluke multimeter as a reference standard. This gives measurement data on the entire range of your Megger.

Seaward

Seaward has a Tool Tester Checkbox that is designed to make calibration safe, simple and quick. It allows regular calibration to be a part of your safety programme. Seaward PAT testers are recommended for calibration on an annual basis. But for low-usage instruments, calibration interval may be extended under certain conditions, i.e. if the test equipment are regularly checked using the Checkbox and there is no deviation in performance.

CEM

All electrical testers are required to have annual calibration. While you can use a calibration checkbox to ensure the continuous accuracy of your CEM device, it does not equal a full in-house calibration which tests tolerances and full instrument ranges in a controlled environment to ensure the manufacturer specifications are met. At Metrotest, we use traceable standards for our calibration services and we issue a detailed certificate outlining all value obtained under calibration.

Aegis

The Aegis PATROL tester has inbuilt functional test features and a recommended manual procedure that must be performed regularly for self-checking the correct operation of the device. The PATROL performs a Self Check on power up and before each test sequence. In addition to these functional tests, Aegis recommends that your tester must still be sent for calibration every 12 months at minimum. If your device is used under harsh environments or is mishandled, the timeframe must be shortened to ensure it operation at peak performance.

Trio

Specifically for the Trio SafeTCheck PAT tester, the routine calibration interval is 12 months. It is recommended that all data is downloaded prior to sending your instrument for calibration, as some data may be lost during the process. The calibration is usually no different from other manufacturers’ testers, and will take anywhere from 2 to 5 days to ensure all results are correct.

Wavecom

Wavecom testers are typically supplied with a calibration certificate valid for 12 months. The manufacturer recommends an annual routine calibration or verification of instruments as prescribed under the AS/NZS 3760:2010 Standard. This must be done only by Wavecome Instruments or by authorised service agents.

During calibration, your PAT tester is checked to ensure operation within certain tolerances. Multiple checks are made are different ‘reference points.’ Depending on the results, your device may or may not need adjustment or repair. The operating firmware may be updated and the calibration settings may be changed.

Kyoritsu

Re-calibration can be done by Kyoritsu, your distributor or an approved calibration house. At Metrotest, our qualified technicians can calibrate and adjust your Kyoritsu PAT tester to all relevant manufacturer and safety standards. We will issue a detailed calibration certificate traceable to national and international standards. Please check that your instrument does not have any structural abnormality prior to sending it for a metrological test.

Calibration is a form of quality and safety assurance, which allows you to use your electrical test equipment with confidence.

For more information, please contact us on 0800 638 768 (NZ) /1800 789 973 (AU) or drop us a line to [email protected].

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You’re Invited To Meet Metrotest At Facilities Integrate

Every year, all the major players in the facilities management and system integration industries in New Zealand gather in one place. Facilities Integrate is a trade exhibition for architects, building operators, electrical service contractors, electrical engineers, property developers, system designer, facility managers, installers and integrators, and professionals in related fields.

On September 25th and 26th, everyone is once again expected to gather at the ASB Showgrounds in Auckland for another unique showcase.

The highly anticipated event offers a chance for all the key players to experience the latest technologies firsthand, showcase their products, participate in relevant seminars and workshops, explore networking opportunities and grab special trade-only deals.

Last year, the show covered an extensive showcase for businesses involved in the operation, maintenance and upgrade of buildings, infrastructure and facilities, as well as those that design, install and integrate ICT and AV systems.

According to their website, this year’s event will “attract large numbers of quality exhibitors, showcase the latest products and services, and cover a variety of public and commercial spaces: including airports, convention centres, defence facilities, municipal buildings, hospitals, hotels, motels, entertainment facilities, office buildings, parks, places of worship, schools, universities, shopping centres, sports stadiums, manufacturing facilities, and more.”

Among the facility management and system integration products, services and technologies included are building management systems, building automation and control, energy management services, grounds care equipment, video project and display, unified communications, HVAC systems, maintenance supplies and technologies, storage solutions, fire protection systems, audio systems and entertainment, and more.

We’re excited to announce that the Metrotest team will be attending this year! If you’re looking to try and buy the latest tools, source the best supplier or stay on top of trends in electrical safety and compliance, come and meet us at the Facilities Integrate 2018. We have so many exciting things to share with you!

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How Was The Test And Tag Training Course?

If you are considering taking our test and tag training course, you will no doubt have some questions as to what you will learn, what you can expect and whether it’s worth it. While we can answer those questions for you, it would be much better to let others who have taken the course  to answer them.

So here is a video we have put together with testimonials from participants of our test and tag course. Let’s see what they have to say:

All these participants took the course, some having taking it several times, and still found the course valuable. We believe the course is truly valuable to anyone who wants to learn to test and tag electrical equipment safely and correctly.

What will you learn?

The AS/NZS3760:2010 course will teach you:

Electrical Regulations
• Standards
• Non-Prescribed Activities
• Competency Requirements
• Safety Before Testing
• Current Legislation/Requirements

Visual/Mechanical Testing including:
• Classes of Equipment
• Electrical Symbols

Testing including:
• Earth Testing
• 500 Volt Insulation Resistance Testing
• Earth Leakage Test
• Other Optional Tests
• Correct Use of PAT Testers
• Practical Testing
• RCD Testing Requirements and Use
• 3 Phase testing upon request
• Necessary actions following successful test results
• Necessary actions following unsuccessful test results
• Interpretation of test periods ie Table 4 AS/NZS3760:2010, Table 3 AS/NZS3012:2010

You can book this test and tag training course on our website or contact us on 0800 638 768 to book your seat.

 

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AlphaPAT Mi2142 Review

The AlphaPAT Mi2142 is by far the best portable appliance tester (PAT) Metrel has ever made. It’s been a top seller in the UK, NZ & Australian markets since 2004.

Although time moves forward and it has much newer competition today, it remains a good choice if you are looking for a tester that does real safety testing, not just compliance testing.

There’s a big difference here. A real safety testing PAT has the ability to really test the protective earth on Class 1 (earthed) equipment at a high current, ideally 10 or 25 amps. On the other hand, a compliance PAT tester tests with a maximum current of 200 milliamps (0.2 amp). Suppliers often won’t tell the uninformed about this, but rather just say it does an earth test. But a test current of 200 milliamps is almost a pointless test!

This low-current-only ability is like testing life jackets by attaching a 20 kg weight – it might be good for a child’s size but not much point if the wearer weighs 90 kg!

More about the AlphaPAT Mi2142

Firstly, it’s a reliable and cost-effective tester which offers downloadable memory and packs an extensive list of additional testing features including touch leakage current, substitute leakage current and low range PE leakage test.

It is powerful yet lightweight. It can store up to 1000 items (test data and results) in its inbuilt memory, which can be downloaded into the default Metrel PATLink software. It also allows you to scan barcode tags (appliance ID field only. There’s also an option for creating PAT reports, writing invoices and exporting data in different formats when you upgrade to SimplyPats 7 Software (purchased separately).

A Brief History

AlphaPAT got its name from Alphatek, the Metrel distributor in the UK at the time. Around the same time it was introduced in 2004, it was changed at the request of Metrotest NZ and an ingenious 3-digit auditable code was introduced. The code started with either a 1 or a 2 depending on the safety class of the equipment to be tested, i.e. Class 1 earthed or Class 2 double insulated.

This coding system is so simple yet so effective when building an auditable system that it is still used today by Metrel and Sonel – the common denominator here being the trademarked SupaPAT, which is available from Metrotest.

Apart from the coding, other things like the ability to perform powered up 3-Phase testing and an automated label printing were also introduced. When used with the printer, the AlphaPAT became a very quick and auditable real safety PAT testing system.

It was eventually to be superseded by the DeltaPAT, which in our opinion isn’t a patch on the AlphaPAT. The Delta has proven popular but most people using the Delta PAT are unaware it is really a compliance only PAT, and those selling it likely just don’t care!

Pros

In many respects, when it was released onto the NZ and AU market, the AlphaPAT was ahead of its time. Even today, there are only a few devices like the AlphaPAT that offers 3-phase appliance testing compatibility – not even big brands like Megger!

The AlphaPAT can perform various auto tests suited for electrical appliances of different types and construction classes. It is well built and mostly easy to work on, unlike another brand starting with an S, which shall remain anonymous. We like the fact that there’s no need to squeeze it in a vice to get it back together.

Calibrations and adjustments are generally easy. Some AlphaPATs tend to drift but usually not between calibrations.

Drawbacks

Admittedly, the AlphaPAT is not perfect. For one, its alphanumeric keypad makes data entry a bit of a drag. This is arguably the biggest reliability issue which is fortunately very simple to fix – you just replace all 23 switches with a better quality switch and problem is solved! Interestingly, the manufacturer never acknowledged the problem even when it became very obvious. Apart from the switches, it has only the normal common part failures like relays, transformers and other electronic components.

To resolve this inherent issue, Metrotest developed an after-market modification whereby another PCB was installed internally to support a QWERTY keyboard.

The fact that the AlphaPAT cannot do the required RCD testing in NZ and AU is another downside. Moreover, the tester downloads via a RS 232 port, which many modern computers don’t have anymore.

Despite all these limitations, there are still multiple users out there with a hundred plus AlphaPATs – we know of one company that has close to 400 of these testers still in use! So we suspect that they’ll still be around for a while!

Final Thoughts 

Summing up, the AlphaPAT is probably Metrel’s best PAT. It joins the list of the best PATs ever built – by any manufacturer!

Metrotest haven’t had more than a handful written off as “can’t be fixed” and, considering their age, that’s pretty impressive.

Should you consider another comparable tester, we believe the best real safety testing PAT alternatives would be the EasiPAT 10, the Alpha SupaPAT and the Ipat SupaPAT. The latter two both draw their DNA from the AlphaPAT and are leading the market of real safety testing devices.

Finally, it’s time to give it a score from a scale of 1 to 10, with 10 being the highest:

  • When it was first released in 2004: 8
  • How it compares now to other PATs on the market: 7

Test well and stay safe!

For more information about safety, click here.

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Who Can Test and Tag Electrical Equipment?

Although test and tag procedure is not mandatory in New Zealand, it is a useful way for employers to meet the legal requirement of ensuring the safety of all plug-in electrical equipment. Testing and tagging involves two parts: first is a visual inspection to check for any signs of damage, and the next is an electrical check using a Portable Appliance Tester (PAT).

Electrical inspection is done on a regular basis, the frequency of which is primarily determined by the type of environment where the equipment is used. For instance, equipment in the construction, demolition and mining sector are required to be tested and tagged every three months. This is due to the harsh nature of the work (i.e. high use, high risk), which is likely to damage the equipment faster.

Which equipment needs to be tested and tagged?

Any device that has a removable plug, a flexible cord and is not low voltage, e.g. extension leads and portable RCD’s.

Portable electrical appliances are classified as either:

  • Class I – earthed appliances such as irons, kettles and toasters
  • Class II – doubled insulated appliances such as hair dryers and electric drills.

New fittings and appliances must be visually inspected and tagged before first use, and consequently at a frequency based on risk assessment and understanding. Used appliances are deemed electrically safe if it is tested, inspected and tagged in accordance with AS/NZS 5761. Used electrical medical devices are specifically test and marked in accordance with AS/NZ 3551.

Who can test and tag?

Contrary to common belief, you do not need to be a registered electrician to test and tag electrical equipment. However, you do need to have the required knowledge and skill in carrying out the procedure.

Electrical (Safety) Regulations 2010 requires that inspection of electrical equipment must be done by a ‘Competent Person’. As per the AS/NZS 3760 In-service safety inspection and testing of electrical equipment, a test and tag personnel must have the following competencies:

  • Knowledge and skill to carry out a visual examination of portable electrical devices
  • Ability to distinguish between double insulated and protectively earthed electrical equipment, and identify the correct test for each class
  • Ability to perform the earthing continuity tests on electrical appliances in a compliant manner
  • Ability to perform the insulation resistance tests in accordance with the standards
  • Ability to test residual current devices or safety switches as per the standards
  • Knowledge in the proper use of relevant testing instruments and interpreting results
  • Understanding of any electrical safety regulations or legislation that may apply in the jurisdiction where testing and tagging is performed.

In other words, the person carrying out the task must have a clear understanding of what to look for and what to do.

Test and tag competency can be achieved by completing training, gaining qualifications, or having experience (or a combination of these) in using a PAT tester and tagging equipment properly. There is currently no recognised or formal registration system for test and tag technicians, although you may receive a “test and tag certificate/licence” after completing a test and tag course.

What this means for you

Whether you are an employer or a self-employed person, you are responsible for ensuring that the person who is inspecting, testing and tagging electrical equipment in your workplace is competent.

You can hire a third-party service to carry out the task. Alternatively, you can purchase your own PAT tester and train one of your workers to use it. Many companies go with the second option for a number of reasons:

  • It allows them to schedule the test and tag procedure around regular work hours, and thus
  • It minimises disruption to the workflow, and
  • It does not hamper productivity

It is also more economical if you have a huge number of portable appliances to be tested and if your equipment is open to abuse. By abuse, it means your equipment is constantly in use or exposed to high heat, moisture, chemical corrosion, or mechanical wear and tear.

Should a device be found to be faulty, it must be tagged as out of action and only a registered electrical worker must fix it.

It is an offence under ES Regulations to tag or mark a fitting or appliance with an incorrect or false tag relating to electrical safety. The person who commits this offence is liable on conviction to a level 2 penalty.

A certificate of conformity or test report that shows that a low-voltage fitting or appliance meets all required standards serves as conclusive evidence that the equipment is safe to use. It is also proof that an employer took steps to ensure an electrically safe worksite.

For test and tag product supply and training, send us a line at [email protected] or call us on 0800 638 768.

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AS/NZ3760:2010 Test and Tag Training Course

Anyone can test and tag portable electrical equipment given that they have undertaken the required competency training and qualification as per AS/NZS 3670:2010. This means you don’t need to be a registered electrician to legally inspect electrical appliances.

What is AS/NZS 3760:2010?

This Standard provides a process for the safety inspection and testing of electrical equipment at various workplaces. It covers portable electrical appliances with a flexible cord and plug (or a connecting device) that connect to the mains supply. Its scope extends to any devices or equipment that is brought into the workplace, such as battery chargers, electric drills, etc.

Safety inspection is a must for new equipment before first use and all other low-voltage, single phase or polyphase equipment in service or is offered for hire. The frequency of the test depends on a preset schedule, as well as on a risk analysis or the environment in which the equipment is exposed.

AS/NZS 3760 puts a lot of emphasis on the test and tag work being carried out by a ‘competent person’, and stipulates the requirements a person needs to fulfil to be considered competent. Working with electrical devices poses a high risk of electrocution and other potentially fatal accidents. Test and tag training not only ensures the equipment is safe to operate but also ensures the protection of the person conducting the in-service inspection.

Test and Tag Training Course

This course provides instruction on how to test and tag electrical devices correctly and safely, as well as how to operate the test equipment which is typically a Portable Appliance Tester (PAT). Additionally, the course teaches regulatory requirements such as tag information, testing intervals, record keeping, different types of equipment and appropriate testing, and other general guidelines.

This course is designed to give you all the skills and knowledge required to being testing and tagging. It also useful for those who are actively testing and tagging, as it contains up-to-date information about relevant regulations and any changes to AS/NZS 3760. It also touches on the standards and regulations that organisations must comply with to prove they are taking all practicable steps to provide a safe working environment for their employees.

Some topics stated in the Standard can easily be misunderstood, which is why test and tag training exists to interpret them clearly. The training must be done by a registered training organisation like Metrotest NZ. By training with us, you can have the confidence of learning from the best. Our trainers have carried out thousands of tests and have a wealth of knowledge to draw on. You’ll also have full lifetime support from one of the longest established test and tag companies in New Zealand.

We conduct trainings in various locations around the country to help as many organisations as possible to become test and tag ready and competent. Many companies are now enjoying the benefits of training their in-house staff. They spend less on testing and have the assurance of a compliant and safe workplace.

View the AS/NZS 3760:2010 Training Courses on our website to find out the available slots and schedules near you. For inquiries, call us on 0800 638 768 or drop us a line to [email protected].