O & M Manual
25
REV D, 2/2007
Part 8 – Service
8.1 General
The information included in this section is intended to be
used to quickly resolve an operational problem with the
system. During any troubleshooting process, it will save the
most time if the operator can first determine if the problem is
related to the transmitter, sensor, or some external source.
Therefore, this section is organized from the approach of
excluding any likely external sources, isolating the
transmitter, and finally isolating the sensor. If these
procedures still do not resolve the operational problems, any
results the operator may have noted here will be very helpful
when discussing the problem with the factory technical
support group.
8.2 External
Sources
of
Problems
To begin this process, review the connections of the system
to all external connections.
1. Verify the proper power input is present (16-35V DC).
2. Verify the loads on any 4-20 mA outputs do not exceed
the limits in the Instrument Specifications (see also
section 4.3.) During troubleshooting, it is helpful to
disconnect all these outputs and place wire-shorts across
the terminals in the instrument to isolate the system and
evaluate any problems that may be coming down the
analog output connections.
3. Do not run sensor cables or analog output wiring in the
same conduits as power wiring. If low voltage signal
cables must come near power wiring, cross them at 90°
to minimize coupling.
4. If rigid conduit has been run directly to the enclosure,
check for signs that moisture has followed conduit into
the enclosure.
