Sensor Fault; Electromagnetic Compatibility - Burkert 8626 Instructions De Service

3.4.4 Sensor fault

This mode is recognized if the sensor voltage lies below a threshold value that is
always present because of intrinsic convection and other effects (i.e. also with zero
flow). In this case, the sensor is faulty or there are contact problems with its supply.
The MFC Type 8626 switches over automatically to the control mode, i.e. the pulse-
duty factor transmitted to the valve is set linearly proportional to the applied set
value. Here, 4 mA or 0 V correspond to the lower value of the pulse-duty factor
determined during valve adjustment and 20 mA or 10 V to the upper value.
NOTE
After a sensor fault has been detected, valve
adjustment (autotune function) can no longer be
activated. To enable you to react in case of a fault,
a signal is additionally placed on relay output 2
(pins 3 and 7 of the 7-pole round connector).
3.5

Electromagnetic compatibility

The MFC type 8626 has a CE conformity certificate for household and industry
applications and has passed the EMC tests according to EN 50081-2:03/94 "Fach-
grundnorm Störaussendung;Teil 2: Industriebereich" and EN 50082-2:02/96 "Fach-
grundnorm Störfestigkeit; Teil 2: Industriebereich".
If nevertheless in the neighborhood of very strong electromagnetic interference
signals, which exceed the thresholds defined in these standards, EMC problems
should occur, a corrective action may consist in shorting the pins for the serial
communication (cf. table in chapter 4)
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Type 8626