ABB PFEA 113, Руководство пользователя

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Tension Electronics PFEA113, User Manual
Chapter 6 Fault-tracing
6-2 3BSE029382R0101 Rev C
6.5 Fault-tracing Procedure
Faults in the... Fault symptoms
Mechanical installation Faults in the mechanical installation usually manifest
themselves as an unstable zero point or incorrect
sensitivity.
If a fault is associated with a process parameter, such
as the temperature, or can be linked with a particular
operation, the fault is likely to emanate from the
mechanical part of the installation.
Load cells Calibration data for a load cell does not change
gradually. A load cell, depending on its size and type,
can withstand up to five times
(1)
the nominal load in
the measuring direction. An event in the process line,
such as web breakage, may cause an overloading
large enough to alter load cell data. Depending on the
amount of overload, it may be sufficient to zero set.
(1) Read more about the overload capacity for your load cell type in Appendix B, C, D, E, F or G.
Cabling Problems such as malfunctions or unstable zero point
may arise from faulty cables or wiring.
Proximity to noisy cables may cause interference
problems.
Incorrect installation, such as cable cores connected
asymmetrically or screens earthed at both ends
instead of only at one end, may show up as an
unstable zero point.
If the polarity of load cell signals is not correct,
the cabling has to be checked.
Tension Electronics Intermittent loss of a function is usually due to a fault
in the tension electronics.
Instability problems seldom originate from the tension
electronics.
Faults in devices connected to the tension electronics
may affect its operation.