Touch the future

Sonel Sonel MPI-540 - new multifunctional meter for electrical systems

The world is developing very quickly. New investments are springing up. They require different types of infrastructure with electrical equipment. Current regulations stipulate that electrical installations and equipment must be maintained in good condition. This ensures safety for people who live and operate in the environment of these devices.

For many years, MPI multifunctional meters from SONEL S.A., have been widely popular among installers as universal and handy instruments with a good price-quality ratio. The new generation of these devices, led by Sonel MPI-540, is a step into the future. Inside the housing, appreciated by users for its convenience and ergonomics, we placed a device that able to perform comprehensive protective measures. Additionally, it allows user to verify the phase sequence and rotation direction of the motor shaft, as well as the measurements of light intensity or the soil resistivity. The device is also provided with a 3-phase recorder of power supply parameters with indication of harmonics in voltage and current.

Fig. 1. Sonel MPI-540 Multi-functional meter

Modern technologies

The new Sonel MPI-540 is a worthy successor to MPI-530, which was our flagship instrument. Development of new technologies provided it with significant improvements. The device has the following unique features.

• 7-inch graphical display with touch-screen, for easy read-outs and operation. It makes all results and messages clearly visible. The display has a wide range of backlight adjustment to provide user with clear read-outs both dark places and in a sunny environment.
• Much faster measurement of fault loop impedance in impedance in circuits with RCDs. The measurement time has been reduced from 30 seconds to approx. 4 seconds. This is more than six time acceleration, which directly reduces time of all measurements, making the whole process more profitable.
• The unprecedented ability to perform any measurements with the power supply from mains. With Sonel MPI-540 you don't have to worry that the battery will run out before the end of measurements. The continuous measurements may be performed using the adapter provided with the meter. With 12 V input, the device may be powered from a car cigarette lighter socket or from portable "power bank"
• The new Li-Ion battery ensures autonomous operation for up to 8 hours. It has no 'memory effect' and offers large capacity and high performance. Full charging of empty battery takes only about 2 hours.
• Extended memory allows user to create a complete structure of measurements for the tested object with the ability to describe objects and points. Each point may have its own history of measurements. This enables the user to quickly assess how results of the tested object change from year to year
• The built-in database of safety features has the option of adding and editing safety functions. As a result, the user may create own, optimised database, which will facilitate the assessment of fault loop measurements.
• The built-in energy loss calculator ensures quick estimation of potential costs resulting from poor quality of power supply. Moreover, active energy tariff calculator provides quick assessment of the most economically advantageous tariff.
• Wireless technologies Wi-Fi and Bluetooth. These technologies are used to transfer data, program the meter, cooperate with mobile applications, cloud, barcode readers, BT headphones and other future technologies.

Fig. 2. Main screen of the meter

Safety above all

Sonel MPI-540 meets the stringent safety requirements of IEC 61010. High safety of the meter is confirmed by its measurement category: CAT III 500 V / CAT III 300 V. Increased protection against external (IP51) is another proof of serious approach of SONEL S.A. to the safety of the product user. CE declaration is a document that finally confirms high safety standards.

The meter is designed to ensure that all the measurements of shock protection features comply with IEC 61557 standard for manufacturers of meters and that the measurement of power supply parameters are performed according to algorithms specified in IEC 61000-4-30 for Class S.

Each meter is provided with a unique calibration certificate, confirming that it maintains the metrological parameters within values specified in the factory standard.

Comprehensive measurements

Multi-functionality of Sonel MPI-540 means that one meter may be used to perform all the necessary measurement specified by PN-EN 60364-6 standard. For an immediate evaluation of the correctness of the tested installation, the user may specify limits for individual measurement functions.

Fig. 3. On-screen keyboard for entering limit values of the insulation resistance

As a result, the meter immediately after the measurement clearly indicates with icon or , whether the result complies with the requirements of the standard or not. The following measurements are available:

The measurement of fault loop impedance with a resolution of 0.001 Ω. It may be performed in electrical installations throughout the world, in L-PE, L-N or L-L circuits. The expected short-circuit current is calculated automatically based on the measured voltage or nominal voltage selected by the user. The measurement is made with the current of approx. 23 A for half the period, which ensures high accuracy. The user may also measure the loop in systems with RCDs without tripping them in a short time (about 4 seconds).

Fig. 4. Measurement of fault loop impedance

Fig. 5. Screen of fault loop impedance measurement

Testing RCDs. Sonel MPI-540 is ready for measuring RCD parameters of all types, i.e. AC, A, F, B, B+, normal, selective and short-time-delay with a nominal current from 10 mA to 1000 mA. An additional, unique feature is the measurement of tripping time and current during one RCD tripping event.

Fig. 6. Screen with the measurement of RCD triggering current

Measurement of insulation resistance. The device offers five test voltages: 50 V, 100 V, 250 V, 500 V and 1000 V. Safety of the user is ensured by the automatic discharge of the tested object after ending or interrupting the measurement. The measuring range is up to 10 GΩ. The measurement may be also performed directly in the sockets, using an adapter with one-phase plug. In multi-phase circuits, the unique AutoISO-1000C adapter may be used. It enables Sonel MPI-540 to automatically perform the required measurements on multiphase cables.

Fig. 7. The screen of resistance measurement with the use of mains plug adapter

Measurement of resistance to earth. There are many methods available: technical 3-wire, technical 4-wire, technical 3-wire with clamps and two-clamp method. 3P (3 wire) method may be used to perform measurements of multiple earth electrodes without the need to disconnect the control connectors. In contrast, the two-clamp method does not require auxiliary probes.

Fig. 8. Screen with earth resistance measurement using the three-lead method

Measuring soil resistivity. Another unique feature is the earth resistivity measurement at different depths (selectable distance between the probes). This feature is essential when designing an earthing system.

Continuity of equipotential and protective connections. The user may perform the measurement with 10 mA current and buzzer or 200 mA current flowing in both directions (continuity test of the protective conductor in accordance with the requirements of the standards), including the compensation of wiring resistance..

Fig. 9. Screen with the continuity measurement of equipotential connection

The tester of phase sequence and rotation of the motor shaft. The meter allows you to check phase direction. To facilitate the measurements, you can use the optional adapters for three-phase sockets of 16-, 32- and 63- amperes. A unique feature is also the measurement of the rotation direction of the motor shaft. This function is very useful to control three-phase motors after their overhaul.

Fig. 10. Checking the phase sequence

Fig. 11. Screen with the check of the motor rotation direction

Light measurements. Using the optional external probe for light metering you may convert the meter into a professional light meter of Class A or Class B, to make the measurements in accordance with PN-EN 12464 standard, including emergency lighting (use the probe with an appropriate measurement resolution).

Fig. 12 Screen with the illuminance measurement

Quick diagnosing of power supply parameters

Sonel MPI-540 offers real-time measurement of parameters which are necessary for a quick assessment of power supply quality. In addition to measuring voltage and current, the meter also measures all power parameters, THD, voltage and current harmonics, unbalance and power factors. As a result, immediately after connecting the instrument to the tested device, you can determine potential causes of malfunction, e.g. difficult start-up of the engine caused by the fifth harmonic.

Fig. 13. Measurement of power supply parameters

It is very important that current data or data saved on a memory card may be browsed and analysed on a built-in 7-inch touch screen. As a result, it is not necessary to connect the meter to a PC. In addition, the unique calculators of energy loss and active energy tariffs facilitate to estimate how much money over time (e.g. on annual basis) is lost due to the poor parameters of power supply. You can also choose the economically optimal active energy tariff.

Fig. 14. Harmonics graph

The standard equipment of the meter provides measurements in single-phase and multi-phase circuits. F-3A flexible clamps with the range of 3 kA guarantee a wide range of applications in measurements. Sonel Analysis software supplied with the meter completes it with the advanced analysis of data taken from Sonel MPI-540 recorder.

Extensive memory

The concept of structured memory, known from MPI-530, has been preserved, but it is substantially enriched with the option of descriptions. "CLIENT– LOCATION – MEASUREMENT POINT" concept works well when the user creates the measurement structure directly during measurements. The number of memory records is essentially unlimited - it depends only from the capacity of the memory card.

Each result saved to the memory may be accurately described. Thus, already during the work, the user is able to prepare a test protocol describing the measuring point and placing it at the appropriate level of the hierarchy. Another option important and useful for the user is the function of uploading the object structure (prepared in "Sonel PE" software) and performing measurements sequentially for given rooms and measurement points. If necessary, the structure can be changed during the measurements.

Each client, object and measuring point has a unique identification number. This will enable future option of meter cooperation with barcode or RFID scanners. This will ensure significant automation of processes used for performing measurements, recording results and drawing up test protocols after.

Fig. 15. An example of a memory screen

The main measurement result is saved to the memory together with additional results, set parameters and test date and time. The memory may be browsed on the meter screen or via "Sonel Reader" software (provided as standard equipment). Optional "Sonel PE" software is designed to prepare the object structure and draw up a complete protocol. To analyse and process lighting measurement results, the user is provided with additional, specialized "Foton 2" software.

Prepared for expansion

SONEL S.A. believes that the best products are developed with the participation of people who use them. Therefore, Sonel MPI-540 is ready for software updates that will add new features and improve the operation of the meter. Shortly after the product release, the users will receive new functionalities, such as automated tests, data read-out via Bluetooth, cooperation with mobile applications and others.

To facilitate the updating process, just login the meter to Wi-Fi network. If new software is available, the device will inform the user and after approval it will download and install the new software from the server of SONEL S.A

Extensive range of accessories

The meter is supplied with a rich set of accessories. In order to efficiently carry out tests, the manufacturer offers test leads (1.2 m), blade probes, crocodile clips, a set for earthing measurements (a probe driven to the ground and 15 m/ 30 m leads on spools), 3 kA flexible clamps for current measurements, adapters with M4/M6 thread, carrying case, accessories and power supply adapter. All measuring accessories comply with safety standards.

Depending on individual needs, the meter may be equipped with accessories from the list of additional accessories. The optional equipment may include clamps for earthing measurements, clamps with a hard core for current measurements, probes for illumination measurement, AutoISO-1000C adapter for automatic measurement of insulation resistance in multicore circuits, longer test leads, extended "Sonel PE" software for creating protocols and others. The full list of accessories is available in the manual and at the website of SONEL S.A.

The wide range of accessories is complemented with a long guarantee period, which is usually 36 months. Attractive solution is the option of extending the guarantee for another 24 months, when the meter is regularly calibrated in an accredited laboratory of SONEL S.A.

Author:
Marcin Szkudniewski
Sonel S.A.