Fault analysis of pressure transmitters
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Removal was carried out on-site; the gauge displayed zero, while the DCS indicated pressure. When power was cut off on-site, an alarm was triggered despite power remaining intact inside the building. After two hours, all faults in the instruments were resolved and normal operation was restored! Dear teachers, please help analyze what causes these malfunction phenomena
I really don’t quite understand it; could you give a simple and clear description?
The header shows zero, while the DCS indicates pressure; in such cases, interference is very likely present.
Connect 475 and check whether the actual output of the transmitter is 4Ma
In 475, it should be the calculated current rather than the actual current, right?
Currently, the main task is to check the gauge range; the signal current was also measured incidentally when a fault occurred
Grounding is good; there should be no interference
It appeared for two hours; now it’s back to normal. I just don’t understand why there was a vacuum in that area, with pressure inside the room
How much pressure? Is there a setting for the maximum or minimum circuit break protection within the DCS system or on the safety barrier (some MTL safety barriers have this feature)?