TechnipFMC 4528, Руководство по установке и эксплуатации

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Page 18 • MNIN003 ║ Issue/Rev. 0.0 (5/19)
Installation / Operation Manual
Troubleshooting
Problem Possible Cause
4728 Readings fluctuate
wildly during flow through
probe, but are steady during
no flow and shake out shows
a steady amount of water.
1. Gas in oil caused by having probe downstream of
a vessel dump valve.
2. Restricted suction to charge pump on L.A.C.T.
unit resulting in cavitation and gas break out.
3. Inner electrode probe is loose.
Output gradually goes up
over a period of time (some-
times only a matter of days
up to several months) with
water cut staying relatively
consistent.
Normally caused by a buildup in probe such as par -
affin, or a film being deposited by flow line chemi -
cals. Often this can be determined by checking from
the probe stud to ground for resistance and capaci-
tance readings after removing the detector chasis.
Resistance reading theoretically should be infinity,
but good results are achievable down to 500,000
ohms. An empty probe should have a capacitance
valve of no more than 95 pf. A full probe with dry oil
should measure between 135 pf to 200 pf depend -
ing on the Dk of the oil with high API gravity oils
reading lowest and low API gravity oils reading high -
est. A digital volt meter set on low DC volts range
should read less than .25 volts. A reading of any
voltage indicates the probe insulators are becoming
contaminated and should be changed. Normally, a
monitor will operate in a normal manner up to .25
volts, but then the readings will become erratic.
Solution to problem is elimination of coating buildup
causes or periodic cleaning of probe with possible
changing out of the probe teflon insulators.
No reading or LED lights on
4728.
No power applied or fuse blown.
No output from 4528 detec-
tor with probe full of oil.
1. No power or probe wire not attached to probe
stud.
Note: Starting in early 1994 a Hi/Low fail-safe
switch was installed. The output will be 8-9 volts
from the detector if the switch is in the hi fail-safe
position and the probe wire is not attached to the
probe.
2. 4528 Detector Card is bad. Replace card.
4-20 mA output varies rapidly
while water cut is steady.
Heavy electrical static in air being picked up by
4-20 mA wiring. Use shielded twisted pair wire for
4-20 mA signal from 4728 Unit to external readout.
Ground shield at 4728 Unit only. DO NOT ground
shield at both ends of wire.
Recommended Spare Parts
1. 1/2 amp slo-blo fuses p/n 68108327
2. Relay p/n 36017183
3. Detector
0-5% p/n 81001164
0-10% p/n 81001160
0-20% p/n 81001161
0-5% (4-20mA) p/n 81001295
0-20% p/n 81001296