Following on from our successful implementation of A.Eberle EOR-D substation level earth fault detection relays, several Swedish Neutral customers have placed orders for EOR-3D Earth Fault Detection Relays for use at feeder level.
The EOR-3D is both an earth-fault and short-circuit passage indicator in an extremely compact housing. In particular, the advantages of different fault detection/location methods can be combined, depending on the fault characteristics. For the first time prioritisation, and thus weighting, of the different fault-locating procedures is possible.
Figure 1. A.Eberle EOR-3D Earth Fault Detection Relay for compensated power systems.
The implementation at feeder level requires very accurate voltage and current inputs as the earth fault currents on compensated systems are extremely low. This has been solved by the use of overhead-line-mounted polymer housed combined current and voltage sensors. They are easy to mount and provide “plug and play” connection with the EOR-3D relay.
Figure 2. Combined CT/VT outdoor sensor for A.Eberle EOR-3D Earth fault Detection Relay.
Often these devices can be located at an established recloser location to use the existing infrastructure of LV supply and communications. However, we also have a solution for standalone applications, with the EOR-3D relay mounted in a stainless-steel weatherproof enclosure complete with battery supply, solar charger and radio comms etc.
If Ethernet communications are available at the device, remote engineering, logbook records and download of Comtrade fault records can also be supported, allowing engineering staff to remotely access the device. Of course, SCADA comms is also supported. With 4GB of internal memory, a substantial quantity of records can be stored for eventual analysis.
The new A.Eberle toolbox software provides a very powerful, yet simple, tool for engineers to understand what is happening at the remote location, and gives a wealth of information (previously unavailable) for analysis of the fault and network conditions.