Introduction
Can monitor 1 x Bender unit Type IRDH265
other benders may be supported - check the Bender documentation to see if the RS485 protocol matches
1 x TX can only monitor 1 x Bender. This is a limitation of the protocol, not the SA380TX.
Data Available
Instantaneous Resistance to Earth
Present Alert Levels
Fault Repeat Relay Status
Alarm Status
Connection Error
AC Fault
DC+ Fault
DC- Fault
Fault Repeater Output
Wiring
RS485
typical rs485 stuff
4-20mA
Not recomended, but could be employed to connect multiple bender units to a single TX by utilising spare analogue inputs.
Be aware that the reading will be prone to error due to the strange equiation used by the 4-20mA signal converter:
R equation
This has to be approximated on an SA380TX using the following equation:
TX equation
ERROR PLOT
The set-up of this is described below
Digtial
Where a fault repeater exists, up to 12 digital outputs may be provided to indicate which sub-feeder is experiencing the worst insulation resistance. These are wired as per standard digital inputs
Configuration & Comissioning
Setting up the Channels
Rs485
Set the RS485 owner to "Bender"
TOUCHSCREEN - CONFIG TOOL
Create a "Bender" slave unit
TOUCHSCREEN - CONFIG TOOL
This will "Create" slave analogue and digital channels
WEB CONFIG OF CHANNELS
Check that device is active:
MAIN SCREEN
REALTIME DIGITAL
REALTIME ANALOGUE
4-20 mA
Wire the input circuit as a "loop powered" 4-20mA input as shown below
4-20MA CONNECTION
You will need to apply a polynomial mapping to translate the 4-20mA output into a resistance
Please ensure you enter the values below EXACTLY
This curve fit is designed to minimise error below 150 k Ohm
Digital
Simply Rename the Digital Channels to match the feeder same (e.g UP, DOWN, BRANCH etc)
Setting the Acquisition
This requires connection via laptop
The touchscreen interface is not sophisticated enough to set this up
Alarm Levels
Use a simple acquire on Change:
TOUCHSCREEN - CONFIG TOOL
Digital Channels
Simply select push-to-server for all physical and RS485 channels
Live Insualtion Resistance
Standard acquire-on-change will grab incoming data based on on absolute change.
This is not desirable when taking insulation resistance readings, as an absolute change of 10 k Ohm from 1 M Ohm to 990 k Ohm will happen very frequently, due to wet weather for instance, and not warrant any corrective actions, where a change from 55 k Ohm to 45 k Ohm would cross an alert boundary and warrant immediate corrective action.
Setting a small threshold will cause a large amount of not very useful data to be captured, whereas setting a large threshold would cause low data volumes, but reduce sensitivity to genuine fault conditions.
To counter this, the "relative" acquire on change must be set on the logger. To do this requires the use of the "Rail Event" feature of the SA380TX
CREATE NEW RAIL EVENT
SET START TRIGGER
SET ACQUISITION
SET END TRIGGER
Set the config