2
02
0-
05
18
Functional Safety KFD2-SR2-Ex*.W(.LB)
Operation
5.1.1
Procedure for Manual Proof Test
Equipment required:
•
Digital multimeter with an accuracy of 0.1 %
Use for the proof test of the intrinsic safety side of the device a special digital multimeter
for intrinsically safe circuits.
If intrinsically safe circuits are operated with non-intrinsically safe circuits, they must
no longer be used as intrinsically safe circuits.
•
Power supply set to nominal voltage of 24 V DC
•
Simulate the sensor state by a potentiometer of 4.7 k
(threshold for normal operation),
by a resistor of 220
(short circuit detection) and by a resistor of 150 k
(lead breakage detection).
Proof Test Procedure
1.
Put out of service the entire safety loop. Protect the application by means of other measures.
2.
Prepare a test set-up, see figures below.
3.
Simulate the sensor state by connecting a potentiometer, a resistor for short circuit detection
or by a resistor for lead breakage detection.
Test each input channel individually.
4.
Connect a potentiometer of 4.7 k
(threshold for normal operation) to the input.
The threshold must be between 1.4 mA and 1.9 mA, the hysteresis must be between
170
µ
A and 250
µ
A.
• If the input current is above the threshold the relay must be activated for normal mode
of operation. The yellow LED lights up.
• If the input current is below the threshold the relay must be activated for inverted mode
of operation. The yellow LED lights up.
5.
Connect a resistor R
SC
(220
) or a resistor R
LB
(150 k
) to the input.
The device must detect an external fault. This state is indicated by red LED and the relay
of the corresponding output must be de-activated.
6.
Test all relay outputs with a specific current, e. g. 100 mA. To avoid electric shock,
use a test voltage of 24 V DC. Check that the relay contacts are open.
The relays must be de-activated. The relay contacts must
definitely open
.
7.
Set back the device to the original settings for the current application after the test.
8.
Check the correct behavior of the safety loop. Is the configuration correct?
9.
Secure the DIP switches to prevent unintentional adjustments.
