Watts PWR4011 - Manual (Page 6)

6
G. Troubleshooting
RO Troubleshooting Guide
sYmPtoms
salt PassaGe PeRmeate FloW PRessuRe DRoP location Possible causes veRiFication coRRective action
Normal to increased Decreased Normal to increased Predominantly
first stage
Metal oxide Analysis of metal ions in
cleaning solution.
Improved pretreatment to remove met-
als. Cleaning with acid cleaners.
Normal to increased Decreased Normal to increased Predominantly
first stage
Colloidal fouling SDI measurement of feed/
X-ray diffraction analysis of
cleaning sol. residue.
Optimize pretreatment system for
colloid removal. Clean with high pH,
anionic detergent formulation.
Increased Decreased Increased Predominantly
last stage
Scaling (CaSO
4
, CaSO
3
,
BaSO
4
, SiO
2
)
Analysis of metal ions in
cleaning sol. Check LSI of
reject. Calculate maximum
solubility for CaSO
4
, BaSO
4
,
SiO
2
in reject analysis.
Increase acid addition and scale
inhibitor for CaSO
3
and CaSO
4
. Reduce
recovery. Clean with an acid formula-
tion for CaCO
3
, CaSO
4
and BaSO
4
.
Normal to moderate
increase
Decreased Normal to moderate
increase
Can occur in any
stage
Biological fouling Bacteria count in permeate
and reject. Slime in pipes
and vessels.
Shock dosage of sodium bisulfite.
Continuous feed of low conc. Of
bisulfite at reduced pH. Formaldehyde
sterilization. Clean with alkaline anionic
surfactant. Chlorine dosage up-stream
with subs. Dechlorination. Replace
cartridge filters.
Decreased or
moderately
increased
Decreased Normal All stages Organic fouling Destructive testing, e.g. IR
reflection analysis.
Optimization of pretreatment system
(e.g. coagulation process.) Resin/
activated carbon treatment. Clean with
high pH detergent.
Increased Increased Decreased Most severe in
the first stage
Chlorine oxidant attack Chlorine analysis of feed.
Destructive element test.
Check chlorine feed equipment and
dechlorination equipment.
Increased Increased Decreased Most severe in
the first stage
Abrasion of membrane by
crystalline material
Microscopic solids analysis
of feed. Destructive ele-
ment test.
Improved pretreatment. Check all filters
for media leakage.
Increased Normal to increased Decreased At random O-ring leaks, End or side
seal glue leaks.
Probe test. Vacuum test.
Colloidal material passage.
Replace O-rings. Repair or replace
elements.
Increased Normal to low Decreased All stages Conversion too high. Check flows and pressures
against design guidelines
Reduce conversion rate. Calibrate
sensors. Increase analysis and data
collection.
Motor Troubleshooting Guide
PRoblem Possible cause coRRective action
Motor fails to start Blown fuses Replace fuses with proper type and rating
Overload trips Check and rest overload in starter.
Improper power supply Check to see that power supplied agrees with motor nameplate and load factor.
Open circuit in winding or control switch Indicated by humming sound when switch is closed.
Mechanical failure
Check to see if motor and drive turn freely. Check bearing and
lubrication.
Short circuited stator Indicated by blown fuses. Motor must be rewound.
Poor stator coil connection Remove end bells, locate with test lamp.
Rotor defective Look for broken bars or end ring.
Motor may be overloaded Reduce load.
Motor Stalls One phase connection Check lines for open phase.
Wrong application Change type or size. Consult manufacturer.
Overload motor Reduce load.
Low motor voltage See that nameplate voltage is maintained. Check connection.
Open circuit Fuses blown, check overload relay, stator and push buttons.
Motor runs and then dies down Power failure Check for loose connections to line, to fuses and to control.
Motor does not come up
to speed
Not applied properly Consult supplier for proper type.
Voltage too low at motor terminals because of line drop.
Use higher voltage on transformer terminals or reduce load. Check connections.
Check conductors for proper size.
Broken rotor bars or loose rotor.
Look for cracks near the rings. A new rotor may be required as repairs are usu-
ally temporary.
Motor takes too long to acceler-
ate
Open primary circuit Locate fault with testing device and repair.
Excess loading Reduce load.
Poor circuit Check for high resistance.
Defective squirrel cage rotor Replace with new rotor.
Applied voltage too low Get power company to increase power tap.