NMi Certin

News letter Utility

You are invited to visit NMi at the European Utility Week

Like previous years, NMi will exhibit at European Utility Week, which will be held in Paris from 12 to 14 November 2019. You can find our team of dedicated experts in the field of residential smart electricity meters, gas-, heat-, and water meters at booth number H163.

We welcome you to visit our booth and meet our experts, while enjoying a cup of coffee or tea with us. You can register for free at our website or make an appointment in advance with one of our Approval Experts; Henri, Wim, Marcel and Carl or our sales team Erik, Rogier, Chuan and Sharmila via nmi@nmi.nl.

WELMEC 11 meeting in Delft

The 8th and 9th October a WELMEC 11 meeting was held in Delft, at the premises of NMi in the Netherlands. Quite some interesting topics were listed on the agenda. For electricity meters the modular approach was discussed. This might be applicable for meters consisting of separate parts, like with a detached indicating device or with separate measuring sensors. A new guide is being prepared for this type of devices. For gas meters the impact of non-conventional gases like hydrogen and biogas was discussed. Another topic was the verification of gas meters at different environmental conditions. And last not but least backflows in networks were discussed, where static gas meters might be sensitive to that. We look back to an interesting meeting! For more info please send an email to nmi@nmi.nl.

New service at NMi: Electrical safety testing of electricity meters

The new IEC standard for electrical safety of electricity meters – 62052-31 – has a major impact on metering design. NMi has decided to invest in this area, in order to offer testing in conformity with this standard: a new service for meter manufacturers.

A few years ago IEC TC13 published the new safety standard 62052-31. This document contains a full set of up to date requirements to cover electrical safety for all aspects of electricity meter design. While having a transitional period of 4 years, in 2020 the document becomes mandatory for the IEC 62052 / 62053 suite of standards.

In Europe, electricity meters are excluded from the Low Voltage Directive (LVD) since many years. One of the reasons for that is the presence of a number of electrical safety requirements in the harmonised standards EN 50470 (and their predecessors). However, this situation has been changed now by the European publication of the safety standard as EN 62052-31, taking over all previous safety requirements, while being referenced in the EN 50470. CENELEC TC13 advised the European Commission to harmonize the EN 62053-31 under the LVD, in order to achieve a levelling playing field for any type of meter.

As a result of the above mentioned developments, it can be concluded that the 62052-31 has become very important. The requirements as described in this standard have to be taken into account for meter designs. Also during the type examination the standard will play an important role.

In order to offer this type of testing to meter manufacturers, NMi recently invested in this new area. This covers all aspects of electrical safety testing, including dielectric tests with AC voltage and impulse voltage tests. But also aspects of the meter housing are investigated. This includes IP testing, using a specific new test chamber for both dust and water, as well as spring hammer testing. The temperature behavior of the meters is also observed, both internally and externally. Besides that the applied plastics are verified, applying the ISO 75-2 test and the glow wire test. In other words, all relevant aspects of the safety standard are included in the examination.

At the beginning of September 2019, the Dutch Raad voor Accreditatie (Council for Accreditation) performed an audit at NMi in order to evaluate the implementation of this new activity. The audit had a very positive outcome. As a result, the new safety standard will be added to NMi’s ISO 17025 scope.

Offering testing conform the new safety standard under our ISO 17025 umbrella is a next step in the one stop shopping philosophy of NMi. Meters can now be examined in accordance with all relevant IEC, EN and OIML standards, including…. the new safety standard!

Interested? Feel free to contact us to discuss this new service!

SMGW’s and smart meters tested for German rollout

In their brand new laboratory in Merseburg (nearby Leipzig, Germany), NMi are testing communication features for smart meters. Although the lab is able to perform necessary tests for devices for the German rollout like smart meters and Smart Meter Gateways (SMGW’s), a number of other aspects can be tested as well, like data security.

In Germany the SMGW will play a crucial role in the communication chain between the installed smart meter and head end system (GWA, Gate Way Administrator). The device needs to meet two sets of requirements. Firstly, the security requirements of BSI CC/PP and TR-03109 have to be fulfilled. This document describes all requirements related to data security, like interoperability, a necessary security module, cryptography and the public key infrastructure.

Secondly, the metrological requirements of the German metrology law have to be fulfilled, where the PTB-A 50.8 plays a crucial role. This document describes all requirements related to the processing and storage of measured data, time measurements and synchronisation, software architecture and correct functioning of the SMGW, without influencing the measurement results.

In NMi’s lab in Merseburg smart meters and SMGW’s are examined, also in combination with GWA functionality. The NMi laboratory cooperates strongly with their partner exceeding solutions. Being specialized in cryptography and computer science, exceeding solutions has successfully installed a dedicated one of a kind test system allowing communication testing with bespoke test scripts.

NMi laboratory

In NMi’s laboratory in Merseburg (Germany), the suitability of smart meters, communication adapters and SMGW’s can be examined, based on the PTB-A 50.8. This comprises various aspects.

For the SMGW’s the lab is equipped with the es:Testsystem, developed by exceeding solutions. This equipment is able to run a number of dedicated test scripts. These scripts cover the individual requirements as laid down in the PTB-A 50.8. By simulating a smart meter, the whole communication chain between SMGW and meter is examined, including all data handling and appertaining time stamps. By simulating the GWA and external market parties, the communication via the WAN network is investigated as well. Also, the HAN network with connection to a local display is examined. Time synchronisation and tariff behaviour is tested by making use of an NTP server as part of the es:Testsystem.

For the meters and SMGW’s, the equipment is able to perform specific latency time measurements for wired and wireless LMN. This concerns the necessary time for the processing of the analogue energy measurements into a digital output, which is examined by means of a comparison with a reference meter with a specific reference clock. In addition, the total time for the processing of the meter data by the SMGW is investigated, while using this equipment.

ISO 17025 accreditation

NMi has an independent accreditation for the examination in accordance with PTB-A 50.8, based on ISO 17025. At the moment also a request is pending at the German Budesministerium für Wirtschaft und Energie, to extend NMi’s existing scope as Notified Body (Konformitätsbewertungsstelle) also for SMGW’s. As soon as this notification will be acknowledged, NMi will be able to issue German national approvals for SMGW’s.

Interested? Feel free to contact us via nmi@nmi.nl in order to discuss your test case, or if you like to come and visit our brand new laboratory.