What is PAT Testing: An Overview

The century we live in is a time of hustle and bustle. Here, you usually look for appliances, which are convenient to carry. Also, these portable devices can make your life much easier. However, as they are electrical equipment, you need to be a little careful while handling them. For this purpose, you can perform PAT testing in periodic intervals to keep yourself from any hazardous event. Then what is PAT testing?

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What is PAT Testing?

PAT stands for Portable Appliance Testing. It is a process to inspect the electrical appliances for their safety level. You can test devices either newly bought or already in service to prevent electric shocks and fire.

PAT testing is a part of health and safety policy. As they test the electrical appliances conform to the safety regulations acclaimed for each product, manufacturers have to perform it at the end of production.

It is not as complex as it sounds; you have to hire a competent person to test by simply looking at the wiring. Still, he may need to combine it with other testing methods to crosscheck the device and check electrical safety defects.

Why PAT Testing?

Under several Health and Safety laws, you have to test your appliances for health hazards if you are a manufacturer. It ensures that you are meeting the legal obligations concerning the safety of your customers.

Portable appliance testing is a part of preventive maintenance. It minimizes the risk of starting electric fires that may cause massive damage to your property and the people you love. Even if you are a user of portable appliances, you need to remember the PAT testing policies and testing frequencies for continual safety.

Moreover, for multiple types of devices, depending on their manufacturing, you will adopt different strategies.

Criteria for Items to Undergo PAT Testing

To undergo a Portable appliance inspection, you have to check these two factors.

  • Electrical Class of your electrical appliance
  • Category of your appliance

These factors are essential to determine whether this type of equipment should be PAT tested or not.

Electrical Classes

Manufacturers categorize the electrical equipment into three main classes,

  • Basic Insulated Class 1 that needs complete PAT testing
  • Extra Insulated Class 2 that needs partial or Insulation PAT testing
  • Low Voltage, Completely Insulated Class 3 needs no PAT testing at all

The following table will help you understand the classes even more.

Electrical ClassInsulation LevelSymbolPAT TestingAppliances
Class 1Low (relies on Earth for protection)PAT testing - class 1 electrical symbolFullPhotocopy Machine, Vending Machine, Washing machine, Fridge, Microwave, Toaster, Kettle, Iron, Electric Heater, Extension Lead, etc.
Class 2Medium (does not rely on earth for protection.
PAT testing - class 2 electrical symbol
Insulation TestingLawn Mover, Drill, Lamp, Food Mixer, Hairdryer, CD Player, DVD Player, Television, etc
Class 3High ( their charging leads may need PAT testing)PAT testing - class 3 electrical symbolNoLaptop, Mobile, Camera, Flash Lights


In addition to the class of your item, you need to see what category your appliance belongs to. Electrical equipment is categorized as follows.

  • Fixed
  • Stationary
  • IT
  • Moveable
  • Portable
  • Cable and Chargers
  • Handheld

The following table will help you understand the categories even more.

CategoryDescriptionRiskVisual InspectionPAT Test
FixedAppliances fastened to support a permanent locationLowYes (in infrequent intervals)No
StationaryFridge, Photocopying MachineLowYes (In high-risk Environment)Yes (Not for Class 2 in a low-risk environment)
ITMonitor, PC, PrinterLowYes (In high-risk Environment)Yes (Not for Class 2 in a low-risk environment)
MoveableItems under 18KG that can be moved around easilyLow-MediumYesYes (Not for Class 2 in a low-risk environment)
PortableEasy to carry anywhereMediumYesYes (Not for Class 2 in a low-risk environment)
Cable and ChargersExtensions lead etc.MediumYesYes (Not for Class 2 in a low-risk environment)
Hand-HeldHair Dryer, Hair Straighteners, Wall drillsHighYes (Frequently)Yes (Not for Class 2 in a low-risk environment)

How often should I do PAT Testing?

With time, you need to maintain your devices so that they do not produce any defects. There are no proper testing policies. However, criteria to determine the frequencies of inspection. 

  • Electrical Classes
  • Categories
  • Risk Level of environment

Moreover, you have to consider the interval between tests depending upon the manufacturer’s recommendations, use and misuse of the item, age, and history of repairing and modifications to do a combined inspection.

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How do I Know if my Business is High, Medium, or Low Risk?

In electronics, you must assess risk as to the potential or uncertainty of electrical equipment short-circuiting or catching fire. Now, you can determine whether the setup you are using the appliances should have what safety standards by considering.

  • Who is using it?
  • What is being used?
  • Where is it used?

For example, consider your laundry room where you wash, dry, and press your clothes. To check the risk level, ask yourself these three questions. Ultimately, you will automatically know it is a medium-risk environment because you use this type of equipment in a wet environment. In addition, for your children, this room is full of accidental items.

This table can help you in determining your Business Risk

EnvironmentRisk LevelReason
Office, Shop, HotelLowUsers are knowledgeable. Equipment is not dangerous
School, HomeLow-MediumEquipment is not risky, but users may be children who are prone to accidents.
HospitalLow-MediumEquipment is not risky. The environment is fast-paced, so that items may get damaged, thus require frequent maintenance.
Industrial BuildingsMediumEquipment may be risky. The environment is fast-paced, so that items may get damaged, thus require frequent maintenance.
Public PlacesHighUsers may be naïve. Difficult to monitor and maintain the devices
Construction SiteExtremely HighHand-held tools may fall and be damaged. Chaotic environment.

Do I Need an External PAT Tester for Frequent Testing?

No, you don’t need an outsider for your PAT testing, as long as you have a competent person on your team who

  • Knows how to carry a PAT test
  • Can identify potential hazardous during the process
  • Can visually inspect the electrical equipment
  • Has prior experience in electrical work

Even if you don’t have someone with these qualifications in your business, no worries, you can invest in a good PAT course and equipment. Moreover, train your interested employees to make them your asset.

Type of PAT Testing

Following are the type of Portable appliance tests that you can go for according to your environment.

Ask User to Keep Checks

You should read the manual or, as a manufacturer, try to educate your user about the problems that might arise in the machine. This way, you can point out the problems way before your electrical equipment is seriously damaged.

For example, if the user knows about a frayed cable inside the device, he can refrain from using it. Else, he may face serious consequences.

Give Formal Visual Inspections

You can call an electrician or your PAT tester to come and look at your device often. This way, they can inspect and repair the damages from time to time. According to HSE, an experienced person can find 90% of the faults simply in one sight.

Combine Visual Examination and Electrical Testing

You have to conduct proper electrical tests in some inspections, as visual inspection is not enough. It is to make sure the level of insulation is still strong enough to support the device from insufficient current soon.

Note that you have to check the inner of the plug whether its internal wiring is good or there is a good fuse. If these two things are missing, your whole appliance will be classified as in high-level risk.

Combine Visual Examination and Electrical Testing

Methods of PAT Testing 

Depending upon the class and category of your portable appliance, you have to choose a service inspection among the following.

Earth resistance test

We opt for earth resistance tests to check the resistance provided to main connection leads by earthing rods. Here, the resistance should not exceed 1Ω. You can test it with various appliances available in stores and online marketplace.

Earth resistance test

Ground Continuity Test

You can perform this test if you want to check the resistance of protective earth connections of the appliance to supply lead. It works on basic principles of Ohm’s Law and checks between the earthed points and the earth pin of the plug.

PAT tester and Ohmmeter both can take the measures in this test. Nevertheless, the electrical test can damage testing equipment in some cases, so you have to take care in the process.

Insulation Resistance Test

Insulation Resistance test checks for the total resistance between any two points with an insulating layer. You can opt for this test if you want to check the insulation quality in the flexible cables of your appliance. You not only can test for it just after manufacturing but also after a long period of a machine’s usage.

Polarity Test

Polarity testing inspects polarities on a socket, whether you have connected the live and neutral connection properly. In appliances, this test can lead to a reduction of short-circuiting up to more than 50%.

RCD Test

RCD testing is the process to check whether RCD in your device trips quickly enough to handle any electrical incident. Moreover, it also goes by the name of Safety Switch testing. You have to apply this test over the period to know how much time an RCD trips. You can also figure out any problems with the device and change it if required to keep the electrical safety barrier up.

Microwave Oven Test

 For a microwave oven, you cannot rely upon traditional methods. Therefore, you need to inspect it the other way round. First, you have to test for its radiations; either their production stops after the door is opened or not. Secondly, you have to check the casing of walls and doors to ensure no leakage has occurred and is safe to use.

About PAT Testers

PAT tests used to be conducted manually, and you always relied upon a person’s experience. Now that the times have been changed, automatic PAT testers have made their name worldwide. From basic PAT tester to advanced, they are easy to operate with accurate answering. You can come across the following types of PAT testers.

  • Pass/Fail PAT Tester: Easy to use and cheap. Blinks light to show results. You can conduct earth continuity, insulation resistance, and polarity tests with it.
  • Advanced PAT Tester: Requires some degree of protection. Shows more information. You can test earth continuity resistance with a specific measurement range, insulation resistance, earth leakage tests, fuse test, and lead polarity.
  • RCD Tester: to test RCD mounted in extensions or multiway adapter.
  • Computerized PAT Tester: Connects to computer via Bluetooth. Can send data to your PC so that you can save the readings for the future.
About PAT Testers


All in all, it would be best to have PAT testing with time so that you do not face electric fires and other damages. Generally speaking, it does require money and time, not if a responsible person has already wired your appliances. Here at Cloom, we offer custom wiring harnesses with attention to each detail so that your devices are easy to maintain. Contact our team and book your service now.

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Hey, I am John, General manager of Cloom and OurPCB.

I am a responsible, intelligent and experienced business professional with an extensive background in the electronics industry.

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