Page 86 - GuardII+ Series 4208 Platform PD User Manual

Troubleshooting

NOTE:
Before looking for a sensor synchronization problem, make sure that the
asset being monitored is running at the time; remember that if the asset
isn’t running, there won’t be a synchronization signal coming from the
sensors.

Use the PD Tester to run measurements as described in Section 7.2 on all inputs that
report a synchronization failure.

• If one or more measurements fail due to lack of synchronization, this indicates a
problem with the data acquisition module. Contact Iris Power LP Technical Support
for assistance.
Using a voltmeter, measure the ac voltage at the end of the input cable from which the
monitor cannot run measurements. The expected ac synchronization amplitude can be
predicted based on the line voltage and operating frequency of the asset; common values are
shown below.
Line Voltage Expected Termination Voltage
(kV, phase-to- (mVrms)
phase) 50 Hz 60 Hz
3.3 58 ~ 86 69 ~ 103
4.16 74 ~ 110 87 ~ 131
6.6 115 ~ 173 138 ~ 206
11 192 ~ 288 229 ~ 344
13.8 240 ~ 360 288 ~ 432
18 314 ~ 470 376 ~ 564
22 383 ~ 575 459 ~ 689
26 453 ~ 679 543 ~ 815

Repeat the same measurement at the termination box.
• If the voltmeter measures the correct voltage and frequency at the termination box, but
not at the end of the input cable, replace the coaxial cable between the termination
box and the monitor. Use an appropriate length of 50 Ω RG-316 coaxial cable
terminated on both ends with BNC connectors. After replacing the cable, check to see
if the synchronization problem still exists.

• If the voltmeter does not measure the correct voltage and frequency at the termination
box or at the end of the input cable, this indicates a problem with the sensor or the
cabling between the sensor and the termination; contact Iris Power LP Technical
Support for assistance.

WARNING:
Under NO circumstances should any troubleshooting be performed on the
termination box while the asset is running. This would be hazardous.

The remaining possible cause for the synchronization problems is electrical noise on the
synchronization signal. While the GuardII+ has built-in filters for eliminating synchronization
noise, there may be cases where there is noise that the filter does not remove. At this point,

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