Technical data
Bender insulation monitoring device IRDH275-435
Nominal voltage: 0...793 VAC, 0...650 VDC
Resistance response values for Alarm 1 and Alarm 2: 1 kohm ...10 Mohm
Supply voltage: 88...230 VAC
Wiring
Typically, the user connects a relay output(s) on the insulation monitoring device to
an overriding system. See the circuit diagram delivered with the drive.
Start-up
Settings of the insulation monitoring device
Set the two resistance response values under the ISO SETUP menu according to
the instructions given in IRDH275 Operating Manual by Bender (code: TGH1386).
The alarm relays are set at the factory.
ACS800-07 frame sizes n×R8i
Check that the internal earth (ground) fault detection is inactivated, i.e. switch S1 on
the supply control board is set to the "disabled" (0 A) position. See ACS800-07
Hardware Manual [3AFE64731165 (English)], chapter Electrical Installation.
ACS800-17 and ACS800-37
The IRDH275 is connected to digital input DI4 at the factory and parameter 30.04
EXT EARTH FAULT is set accordingly.
Functional test before start-up
The function of the IRDH275 has been tested at the factory.
Fault tracing
The Bender IRDH275 continuously monitors the IT system and earth (PE) as a
factory setting. In small systems, the normal insulation resistance without an earth
fault may be high enough to cause false alarms (as if the supply connection was
missing). In such cases, switch the connection monitoring off in the ISO SETUP
menu, by selecting the sub menu Memory: on/off.
Pressing the RESET button resets the fault message, provided that the currently
displayed insulation resistance is at least 25% above the set resistance response
value.
Earth fault monitoring in IT (ungrounded) systems (+Q954)
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