Watt-Hour Precision

Anyone who pays for energy wants to know exactly how much has been supplied and at what price. This is nothing new; however, in times of rising energy costs, it has become more important. In addition, both e-mobility and the increase in the renewable energy being fed into the national grid system have made consumption billing in compliance with calibration law a much more demanding challenge. WAGO energy meters are well equipped for all tasks in the building and industrial sectors.

As long as car manufacturers provide their customers with free electricity via their own charging infrastructures, kilowatt-hour precision in billing won’t be users’ top priority. No one looks a gift horse in the mouth, and no one looks too hard at prices or precise consumption data. But as soon as consumers have to pay for that energy, their behavior changes. Therefore, charging stations in Germany need meters that comply with calibration law. This applies not only to charging stations for e-vehicles, but also to network feed-in of solar energy and sub-metering contracts, such as are found in retail – wherever providers bill for energy, suitable meters need to be used. This is the only way to guarantee that the consumption billing complies with the law.

The basis for this is MID Directive 2014/32/EU. The so-called Measuring Instruments Directive (MID) is a European Union regulation intended to harmonize many aspects of legal metrology in all EU countries. It applies throughout the EU to all types of measuring instruments: from water meters, to electrical energy meters, to scales and taxi meters. The MID sets basic performance standards for measuring instruments, sets requirements that apply up to initial commissioning and governs manufacturers’ obligations. In addition to compliance with calibration law, WAGO’s energy meters with MID certification offer other benefits, which can be demonstrated by four example applications.

WAGO energy meters can be used for AC charging systems. The measured values are forwarded to the higher-level controller via the integrated interfaces – M-Bus, Modbus^® and two S₀ interfaces. This gives manufacturers of charging stations and wallboxes maximum flexibility, since all these interfaces can be operated with one universal MID meter series.

The Bluetooth^® interface is especially beneficial: Using the free “WAGO Energy Meter Configurator” app makes it easy to both read out data from the energy meters and configure them. Therefore, a default configuration can be easily transferred to each additional device. The energy meter has multiple configurable inputs and thus offers billing according to four different rates, which is of particular interest for use in charging infrastructure systems. For example, this can be used to bill energy separately for the company’s own vehicles and external vehicles.

The WAGO energy meters with transformer connection can be combined with plug-in current transformers, Rogowski coils, split-core current transformers and voltage taps for insulated conductors. They follow module D of the conformity assessment procedure. The quick-mount kit makes installation quick and inexpensive. The transformer-operated meter is especially useful for retrofitting existing systems, e.g., production equipment or power distribution stations, because the wiring process for the retrofit is very easy. This design variant accommodates currents up to several thousand amps.

Easy screwless connection, powerful communication capability and wireless readout and configuration via app – these are just a few of the WAGO energy meter’s impressive features. In addition, MID compliance per Directive 2014/32/EU makes them an ideal partner for consumption billing.