Fault Symptoms And Measures - ABB PFEA 113 User Manual

Tension Electronics PFEA113, User Manual
Chapter 6 Fault-tracing

6.7 Fault Symptoms and Measures

6-4
General remark:
If the free (unscreened) cable length exceeds 0.1 m (4 in.) the individual pairs of power and
signal conductors must be twisted.
Free length exceeding 0.1 m can cause unstable zero point or incorrect absolute measurement
value.
Fault symptom
Noisy signals
Unstable zero point
Display and LED indictors are
not illuminated
Table 6-1. Fault Symptoms and Measures
- Check that cable shields are connected to earth
according to cable diagram.
- Proximity to noisy cables can cause interference
problems.
- Check that cable screens are not connected at
both ends.
- Check that cable between load cell and electronic
has diagonal pairs, one pair for signal circuit and
one pair for excitation circuit, see
- If a junction box is installed, check that load cell
signal and load cell excitation between junction
box and electronics are routed in separate cables.
- Check, if two or more IP 20 units are mounted
close to each other in the same cabinet, that they
are synchronized (cable for synchronizing the
units, see cable diagram and
Synchronization).
If the Operator panel display is not illuminated and
the "Power" and "Status" indications are on and the
Operator Panel is "OFF", check the following:
- Check that the cables are correctly connected to
the electronics power supply.
- Check that the power supply connected to the
electronics is correct.
- Check that the power switch is "ON" (inside the
IP 65-version (NEMA 4) enclosure).
- Further tests are described in
Supply Error.
Measures
Figure 2-2.
Section 2.4.1.3
Section 6.8.1.3
3BSE029382R0101 Rev C