Proof Test; Proof Test Procedure - Pepperl+Fuchs KCD2-SR-1.LB Safety Manual

Safety Manual SIL KCD2-SR-(Ex)*(.LB)(.SP), HiC282*

Proof Test

4 Proof Test
4.1

Proof Test Procedure

According to IEC 61508-2 a recurring proof test shall be undertaken to reveal
potential dangerous fails that are otherwise not detected by diagnostic test.
The functionality of the subsystem must be verified at periodic intervals
depending on the applied PFD
manual. See chapter 2.4.
It is under the responsibility of the operator to define the type of proof test and the
interval time period.
The ancillary equipment required:
Digital multimeter with an accuracy better than 0.1 %

For the proof test of the intrinsic safety side of the devices, a special digital
multimeter for intrinsically safe circuits must be used.
Power supply set at nominal voltage of 24 V DC

The settings have to be verified after the configuration by means of suitable tests.
Procedure:
Sensor state must be simulated 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).
The input test needs to be done for each input channel individually. The threshold
must be between 1.4 mA and 1.9 mA, the hysteresis must be between 170 µA
and 250 µA.
For normal mode of operation the relay must be activated (yellow LED on), if

the input current is above the threshold.
For inverse mode of operation the relay must be activated (yellow LED on), if

the input current is below the threshold.
If the resistor R
the unit must detect an external error. The red LED shall be flashing and the relay
of the corresponding channel shall de-activate.
Both relay outputs need to be tested with a certain current, i. e. 100 mA. To avoid
any electrical shock problems, we recommend to use 24 V DC for this test. For
the philosophy of Functional Safety it is important to test, that the relay contacts
are definitely open, if the relay is de-activated.
After the test the unit needs to be set back to the original settings for the current
application. Further the switches for the settings need to be saved against
undeliberate changes. This can be achieved by means of a (translucent)
adhesive label, for HiC units across the hole where the switches are underneath,
for KCD2 devices by fixing the label flap.
Intrinsically safe circuits that were operated with non-intrinsically safe
circuits may not be used as intrinsically safe circuits afterwards.
(220 ) or the resistor R
SC
in accordance with the data provided in this
avg
(150 k) is connected to the input,
LB
13