Product description
The insulation fault locators ISOSCAN® EDS460/490 in combination with the ISOMETER® IRDH575 or the locating current injector PGH are applied for localising insulation faults in unearthed systems (IT systems). The locating current signals generated by the insulation monitoring device IRDH575 or the locating current injector PGH are detected by measuring current transformers and evaluated by the insulation fault locators. Up to 12 measuring current transformers can be connected to one EDS460/490. A total of 90 EDS insulation fault locators can be connected via one RS-485 interface (BMS protocol). Hence, up to 1080 circuits can be monitored. The maximum scanning time is …10 s, see TGH1394.
Application
• Insulation fault location in AC, AC/DC and DC IT systems
• Main and control circuits in industrial plants and ships
• Diode-decoupled DC IT systems in power stations
• Systems for medical locations
Device features
• Insulation fault location in IT systems
• For AC, 3AC, DC and IT systems
• Control and display function in a single device (EDS…-D)
• 12 measuring channels (circuits) for measuring current transformers of the W, WR, WS series
• Up to 90 EDS insulation fault locators in the system (1080 measuring channels)
• Scanning time max. 10 s for all measuring channels (parallel scanning)
• Response sensitivity EDS460/490 2…10 mA, EDS461/491 0.2…1 mA
• History memory to store 300 events
• Two alarm relays with one changeover contact each
• N/O or N/C operation, selectable
• Connection external test/reset button
• Indication via graphical display resp.7-segment display and alarm LEDs
• BMS address range 1…90
• Serial interface RS-485
• Continuous CT connection monitoring
• Fault memory behaviour selectable
• Device version EDS490/491 with one alarm contactor per channel
• Additional AC residual current measurement

Function
Insulation fault location is started manually or automatically via the ISOMETER® IRDH575 or the PGH. Once started, the insulation fault locator EDS simultaneously scans all measuring current transformers (channels). If several EDS exist, these devices are also scanned simultaneously.
When the locating current detected by a measuring current transformer exceeds the set response value, the alarm LED 2 lights up, the common alarm relay switches and the faulty circuit is indicated as plain text on the graphical display. Version EDS…L indicates faulty outgoing circuits via alarm LEDs. The connection between the measuring current transformer and the insulation fault locator is continuously monitored. In the event of wire interruption, the alarm LED 1 lights up and the alarm relay switches.
With the fault memory activated, the alarm messages of the individual channels remains stored until the reset button is pressed or until a reset command is given via the RS-485 interface. When the fault memory is deactivated, the alarm message remains stored until the insulation fault is eliminated.
History memory in EDS460/461-D/EDS490/491-D
The device utilises a history memory for failsafe storing of up to 300 measured values/ events (date, time, channel, event code, measured value), so that all data about an outgoing circuit or an area can be traced back at any time (what happend when).
AC residual current measurement
EDS insulation fault locators can also be used for the indication of AC residual currents in unearthed power supplies (IT systems). This is essential when also AC residual currents are to be localised in the circuits.
Device variants
EDS460-D
Device version EDS460-DG features a backlit graphical display where information can be displayed in various ways. This version is applied when detailed information about all devices in the switchboard cabinet, connected to the bus, are to be displayed locally. This device is capable of assigning parameters to all devices connected to the BMS bus and displaying all measurement details. Several EDS460-DG devices can be used in one system.
EDS460-L
Device version EDS490D/EDS490L utilises a two-digit 7-segment display where the address of this device is displayed within the BMS bus. Various error codes are displayed too. The alarm LEDs indicate in which measuring channel the response value has been exceeded. Parameter setting is only possible via an EDS…D, an ISOMETER® IRDH575, the alarm and test combination MK2430 or the protocol converter COM460IP.
EDS490-D/EDS490-L
In comparison to the device version described before, EDS490-D/EDS490-L feature a galvanically isolated alarm contact (N/O contact), for example, to trigger a circuit breaker in this subcircuit when a response value has been exceeded.
EDS461-D/-L and EDS491-D/-L
In comparison to the device versions described above, these versions provide a higher response sensitivity. They are preferrably used in control circuits or in medical locations up to AC 230 (DC 220) V.
Core technical parameters
Measurement performance parameters | Parameter categories | EDS460/490 | EDS461/491 |
| Insulation fault location response value | 2... 10mA | 0.2... 1mA | AC residual current measurement range | 100mA... 10A | 10mA... 1A | | Number of channels (single device) | 12 (supporting W/WR/WS series measurement current transformers) | 12 (supporting dedicated high-sensitivity measurement current transformers) | | | Maximum number of networking devices | 90 (total 1080 measurement channels) | 90 (total 1080 measurement channels) | | Full channel scanning time | Approximately 8... 24 seconds | Approximately 14... 30 seconds | | Response delay (t_on)) | 0... 24s (adjustable) | 0... 24s (adjustable) | | Release delay (t_off) | 0... 24s (adjustable) | 0... 24s (adjustable)|
Email:wang@kongjiangauto.com