EA-ENS2 NA Mains Power Monitoring system
General description
The module ENS2 is a separately installed, integrated grid protection equipment, also called automatic isolationunit (AIU), designed to meet german standard VDE-AR-N 4105. The specifications of that standard are suitable formost european countries running three-phase supplies 400V (L-L) resp. 230V (L-N). The AIU is intended to cut theconnection between a power generating or energy recovering device (here: electronic load with energy recoveryfeature) and the public AC supply grid on distortions regarding voltage or frequency, by means of controlling twoserial contactors (with or without feedback contact).
The internal supervision circuit monitors the three phases of the public grid for fluctuations of voltage and frequency.In case certain supervision thresholds, as defined by the standard, are exceeded it will cut the power generationdevice from the public grid by means of two breakers (contactors, two pieces for safety of 100% cutting off).
When operating electronic loads with energy recovery feature, such as of series ELR 9000, ELR 9000 HP, ELR10000, or recuperating power supplies such as PSB 9000 and PSB 10000, this kind of supervision equipment isabsolutely required if it can occur that the device runs in a so-called “isolated operation” or in case the local electricsupply company demands such a supervision device. Isolated operation means, that the device might be supplyingenergy back to the grid (local or public), but there are no consumers in proximity which partly or fully consume theenergy which is usually the case when a main supply point has been shut down for reasons of maintenance andthere is no voltage expected anymore on the line.
The above mentioned VDE standard only defines the parameters for operation of this equipment in Germany.Whether the german standard meets specifications in different countries can not be determined by the manufacturer of the equipment, but the end user. In case of doubt it must be found out whether it’s required to install gridprotection equipment to allow operation of such a recuperating device. It’s supposed that other european countrieshave similar standards and/or provisions for this type of equipment and its operation.
