Testing the safety of electrical devices and welding machines – what to use and how to perform it?

Verifying the safety of electrical equipment requires reliable measuring devices designed for challenging field and industrial conditions. Thanks to their advanced features and intuitive operation, the state-of-the-art PAT-96 and PAT-95 meters from Sonel ensure precise and compliant safety measurements of electrical appliances, power tools and welding machines. It is a perfect solution for the most demanding users.

Precision and reliability in testing electrical equipment

Electrical and welding equipment safety testing must comply with applicable standards to ensure the user protection and the reliability of the tested devices. The key factor is the use of a measuring instrument that not only allows for data recording and archiving, but also has documents proving its efficiency – a declaration of conformity or a calibration certificate. In response to these requirements, Sonel has developed the PAT-95 and PAT-96 meters, devices that combine the top-quality craftsmanship with reliability and compliance with industry standards.

Image 1. Sonel PAT-96 meter kit including a printer and scanner

Comprehensive tests: from protective conductor resistance to leakage currents

One of the first stages of the inspection is performing a visual test. The Sonel PAT-95/96 meter allows for customising of this test to the individual requirements of the user. During the measurement, the device guides the operator step-by-step, forcing the verification of specific elements and confirming this action by selecting the appropriate options on the screen. The range of inspected elements can be predefined while creating the measurement procedure or extended during the test.

By measuring the resistance of the protective conductor with currents of 200 mA, 10 A, 25 A, the continuity of the protective connections in equipment can be accurately assessed. This function operates up to 19.99 Ω, with a high resolution from 1 mΩ, and is the basic test to be performed for class I devices.

Figure 1. R_PE R_ISO measurement scheme

One of the key elements in assessing the electrical device safety testing is testing the insulation resistance. It enables the detection of insulation damage that can lead to short circuits, electrical shocks or equipment failure. The PAT-95/96 meters from Sonel offer an insulation resistance measurement function selectable test voltage range from 100 V to 1000 V. It allows the user to adjust the measurement voltage to the specific requirements of the tested devices, minimising the risk of damage while ensuring measurement accuracy. With a measuring range of up to 599.9 MΩ, it enables precise evaluation of the insulation condition.

Another important aspect of testing electrical devices and machinery is the measurement of leakage currents. The PAT-95/96 meters from Sonel enable measurements of the following types of current:

substitute current (I_sub),
direct current (I_PE),
residual current (I∆),
touch current (I_T).

Each of these measurements provides valuable information about the condition of the device insulation. While measuring the substitute leakage current, the meter applies a reduced safe voltage and converts the result into the current that would occur under nominal voltage conditions. It is possible to change polarity when measuring residual current, touch current, and in the PE conductor. In addition, the measurement of residual leakage current and the current in the PE conductor can be carried out using clamp meters, which facilitates work with devices permanently connected to the power supply.

The IT measurement measures current flowing to the ground from a component insulated from the power supply circuit, when this component is shorted. This value is associated with the corrected touch current. This is the touch current that flows to earth through a probe simulating the resistance of a human being. The EN 60990 standard gives a human resistance of 2 kΩ, and this is also the internal resistance of the probe.

Image 2. Automatic measurement of a device in class II protection using PAT-96 from Sonel

In addition, the meters enable testing of residual current devices (RCDs and PRCDs), checking the tripping time and current.

Specialised features of PAT-96 from Sonel for welding equipment

The PAT-96 from Sonel was developed for testing welding equipment for compliance with the PN-EN 60974-4 standard. With the meter, it is possible to measure the voltage of the welder without load, measure the leakage current of the welding circuit and measure the primary leakage current.

Sonel PAT-95:

measurement of protective conductor resistance with current up to 25 A;
measurement of insulation resistance with voltages up to 1000 V;
measurement of substitute (I_sub), direct (I_PE), residual (I∆) and touch (I_T) leakage currents;
testing of residual current devices (RCDs) and portable residual current devices (PRCDs);
testing of the SELV devices;
device functional tests.

Sonel PAT-96: dedicated features for welding equipment:

measurement of the voltages without load(U₀);
testing of the welding circuit leakage currentI_P);
testing of the primary leakage current (I_L).

Sonel PAT-95 and PAT-96 are universal in terms of power supply and device testing, which means they can test devices power supply voltages of 110 V and 230 V. The meters are suitable for different types of electrical networks, such as TN and IT systems.

Intuitive operation and measurement automation

PAT-95 and PAT-96 from Sonel are equipped with a high-resolution LCD touchscreen (1280 x 720 pixels), making operation of the device simple and convenient. One of the key elements that distinguish the PAT-95 and PAT-96 meters from Sonel is the built-in measurement procedure wizard. It has been created to make the job easier, both for experienced professionals and users who are just starting their journey with testing of electrical devices. The wizard not only automates measurement processes, but also increases efficiency and minimises the risk of errors, while a built-in instruction system assists the user during the tests.

Quick and clear record-keeping through label printing

The PAT-95 and PAT-96 meters from Sonel have been designed to make device documentation and record-keeping as easy as possible. Thanks to its compatibility with portable printers, users can print reports and labels that are affixed to the tested devices immediately after the measurements. This solution allows for immediate labelling of devices, which significantly facilitates document management and eliminates the risk of confusion.

Printed labels contain key information, such as:

measurement results,
the date of testing and the registration number of the device,
QR code, which allows quick access to details stored in the meter memory or management system,
other important information, depending on the selected format of the label to be printed.

This feature is particularly useful in large industrial plants and power tool rental companies, where many devices are tested on a daily basis and a quick and clear record-keeping is essential. The printing is done automatically, immediately after the measurement is completed, which saves time and ensures seamless execution of subsequent tasks. It is also possible to print from memory. As a result, PAT-95 and PAT-96 from Sonel not only guarantee accurate testing, but also improve the efficiency of the entire device management process.

Multifunctionality and adaptability to different working environments

Thanks to their design, PAT-95 and PAT-96 from Sonel can be used in a variety of environments. These devices are perfect for:

inspection of domestic appliances and power tools,
testing of three-phase devices,
diagnostics of welding equipment.

Image 4. Company safety audit using the PAT-96 meter from Sonel

Compliance with international standards

The PAT-95 and PAT-96 meters from Sonel meet the requirements of numerous international standards, such as:

EN 50699
EN 50678
EN 60974-4
VDE 0701-0702
VDE 0404-1
VDE 0404-2
EN 60745-1
EN 62841
EN 60335-1
EN 60950
IEC 62368-1
AS/NZS 3760
other

Thanks to their wide range of compliance with standards, PAT-95 and PAT-96 from Sonel can be successfully used in any industry requiring precise and compliant measurements.

Summary

Both meters feature a robust design that provides protection in challenging field conditions. The IP40-rated housing ensures resistance to dust and mechanical damage, while the compact dimensions (318 x 257 x 152 mm) makes transportation easier.

PAT-95 and PAT-96 from Sonel have communication modules (WiFi, Bluetooth) and USB and LAN connectors.
The devices are designed to operate within a wide range of temperatures (-10°C to +50°C) and humidity (20–80%), making them reliable in all conditions.

In summary, PAT-95 and PAT-96 from Sonel redefine the concept of safety in electrical device testing. Combining innovative technology, intuitive operation and advanced measuring features, they provide indispensable support for professionals concerned with the safety of electrical and welding installations.

Author: Michał Cichoń, Sonel S.A.