PART FOUR - SERVICE AND MAINTENANCE
SECTION 3 - TROUBLESHOOTING
Rev. 6-501
Model P53 pH/ORP Analyzer (universal-mount 1/2 DIN)
93
Finding Source
of Ground Loop
☞
3.2 Isolating Measuring
System Problem
Checking Electrical
Connections
Verifying
Sensor Operation
Verifying
Analyzer Operation
Sometimes the source of a ground loop is easy to find, but it
usually takes an organized approach to isolate the problem.
Troubleshooting Tip!
Use a systematic troubleshoot-
ing method. If possible, start by grounding all shields
and electrical grounds at one stable point. One at a
time, turn off all pumps, motors and switches that are in
contact with the process. Each time you do this, check if
the ground loop still exists. Since the process media
being measured is electrically conductive, the source of
the ground loop may not be readily apparent.
When experiencing problems, try to determine the primary
measurement system component causing the problem (sen-
sor, analyzer or interconnect cable, if used).
1. Verify that line power exists at the appropriate analyzer
TB3 terminals.
2. Check all analyzer cable connections to ensure they
are properly connected.
To verify sensor operation, refer to the procedure in the
troubleshooting section of the sensor operating manual.
WARNING:
DISCONNECT LINE POWER TO AVOID THE
POSSIBILITY OF ELECTRICAL SHOCK.
1.
After disconnecting line power from the analyzer, dis-
connect the sensor.
2.
Depending on the type of sensor, refer to the appropri-
ate category below and follow the steps to simulate a
pH (or ORP) input signal and a temperature signal:
For GLI Differential Technique Sensor
A.
Connect a millivolt generator (or a jumper, if gen-
erator is not available) between Terminal 20
