Function
8
2.3 Starting sequence
Once the residual current monitoring module is connected to the power supply, the automatic
starting sequence begins.
The residual current monitoring module RCMB101 is supplied by an external power supply.
Supply voltage fluctuations may influence the residual current measurement. To exclude this effect
(particularly during calibration), the starting sequence is as follows:
Supply voltage measurement
1. Once a supply v
U
s
≥
5 V is applied, the starting sequence begins .
2. The residual current monitoring module disables the open collector switching output X12
(HIGH level).
Calibration
3. When a supply voltage of +
U
s
≥
11 V is reached, calibration (offset measurement) is started by
the module. It must be ensured that no residual current is flowing.
4. Once calibration is complete, the supply voltage measurement will be repeated. Where the
con
U
s
≥
11 V cannot be fulfilled, calibration will be repeated. After successful calibra-
tion, the residual current monitoring module enables the switching output X12 (LOW level).
Test current supply
5. The test winding is supplied with test current for 2 s (two-stage test current). The resulting
measured value is available at X1 and the corresponding switching state is applied to output
X12.
When the current is supplied to the test winding, X1 drops to LOW level. X12 will only be enabled
when a HIGH level is applied at X10.
Other features
6. When the test winding is supplied with current, the behaviour of the residual current module is
determined by the control input X10:
Note:
Users must ensure that the supply voU
s
und -U
s
at X2 / X11 are strictly
observed. Otherwise the signals at the outputs X1 and X12 may be outside the
tolerance range!
Test current supply
Test current
Duration
Output X1
Output X12
First sequence
11 mA, 400 Hz
1 s
1.2 V
does not switch
Second sequence
DC 22 mA
1 s
4.85 V
switches after max. 800 ms
Impulse duration at X10
(HIGH)
Behaviour of the RCMB
≤
50 μs
The input is monitored until an impulse of T
≥
50 μs is applied.
50…100 μs
Self test (supply voltage measurement, calibration and test current
supply) will be repeated
> 100 μs… < 5 ms
Control input X10 will be queried again
> 5 ms
Residual current measurement starts after 10…11 ms
