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8024252/AE00/V1-0/2020-07| SICK
O P E R A T I N G I N S T R U C T I O N S | ZIRKOR200 Ex-D
Subject to change without notice
LAYOUT AND FUNCTION
4
4.6
ATEX / IECEx certification
The control unit of the ZIRKOR200 Ex-D oxygen measuring system is not Ex-certified and
must be installed in the safe area. The probe may be installed in Zone 21 environments
(certified II 2D Ex tb IIIC T133 °C/T141 °C Db).
4.6.1
Ignition source monitoring of the probe by means of temperature monitoring
The temperature of the probe is monitored by an additional electronic system (Part No.
2105158) with two thermoelements. The electronics are designed to be fail-safe
(redundant). It automatically switches off the probe heating when the operating
temperature of the probe is exceeded. The switch-off temperature is 810 °C. In addition,
the heating is switched off in the event of a fault in one of the thermoelements. The
electronics go into self-holding mode, which means that if a fault occurs, the electronics
must be reset. The electronic card must be checked every three years by the manufacturer
for safe operation. The next test date is on the sticker on the electronic board. (
ing shutdown in case of malfunction”, page 69
Fig. 6: Sticker with test date
Note:
To ensure the maximum permissible surface temperature, the probe is switched off
when the operating temperature exceeds 810 °C and can only be heated up again by
restarting. The recording of the operating temperature is done redundantly with 2
thermocouples in a sheathed thermoelement.
Switching off is performed by a protective device independent of the controller and SIL
certified for this purpose.
The operating temperature of the probe is 800 °C.
WARNING:
The covers of the probe junction unit must not be opened during operation. Before
opening after switching the system off, make sure all probe components meet the
condition of surface temperatureT133 °C / T141 °C. The minimum waiting time after
switching off is 1 hour.
If the ambient conditions can be classified as not potentially explosive, work on the
probe can also be carried out in the operating state.