Bender FTC470XET, Руководство по эксплуатации

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51 TGH1375en/02.2010
7.2.5 Discriminator circuit with RCMS470-12 (Monitoring a "window")
The operating current on a conductor may fluctuate between 11 mA and 30 mA. When the
value is outside the permissible range, an alarm is to be signalled. The conductor is moni-
tored by one CT, the input channels 2 and 4 of the residual current monitor are connected
in parallel and therefore receive the same CT signal. In order to compensate the input resist-
ance which is divided by two, the correction factor 2 has to be set for both channels. Channel
2 has to take over the overcurrent monitoring function, channel 4 the undercurrent monitor-
ing function. A prewarning level of 90% of the preset response value is to be set for all chan-
nels.
1. Select: "Address 5: RCMS470-12“ from the main menu. The respective setting submenu will appear.
2. Click "Set response values". A list displaying each channel with its associated CT correction factor will
appear. Enter correction factor *2 for both channels. Enter the response value 31 mA for channel 2
and an undercurrent response value of 10 mA for channel 4. Confirm your actions with the "Save"
button or stop your actions with "Cancel“. If you have selected "Save", an alarm message will be out-
put when the upper or lower response value threshold will be reached. An example is given in the
screen shots below.
Submenu: Set response values
Channel 1 to 12: Factor
(CT correction factor)
- Division by 2 to 10,
-
multiplied by 2 to 250.
Response value
- Overcurrent/residual current
- Undercurrent
Prewarning - Percentage of the response value (90%)