20
17-
04
20
Functional Safety KFD2-SH-Ex1(.T)(.OP), KHA6-SH-Ex1
Operation
Proof Test Procedure
1. Prepare a test set-up, see figure below.
2. Simulate the state of the sensor
- 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)
3. Connect a load of 1.3 k
to the voltage output of the .T(.OP) device.
4. Supply the relay contact output by 24 V DC externally. Connect an 1 k
resistor as load to the relay contact output. Test this configuration with a
multimeter for the state (on).
5. For versions with triplicated relays, test each single relay with a multimeter if
the off state is reached.
The input threshold must be between 2.1 mA and 2.8 mA. The hysteresis
must be between 170
µ
A and 250
µ
A (measured with input multimeter and
potentiometer).
If the input current is above the threshold,
- the voltage output must be activated, voltage level higher than 20 V DC
(.T(.OP) version only),
- the relay contact output must conduct (approx. 24 mA over 1 k
),
- the yellow LED must be on.
6. For the functional safety it is important that the voltage output is
definitely off
(less than 1 V DC) and each single relay contact output is
definitely open
(high impedance)
, if the input is below the lower threshold (typ. 2.5 mA) or
above the higher threshold (typ. 6 mA).
7. Connect the resistor R
SC
(220
) or the resistor R
LB
(150 k
) to the input.
The red LED must indicate the fault, the voltage output is off, the relay
contact outputs are high impedant (> 100 k
).
