23
troubleshooting
Trouble
Cause
Remedy
Motor does not come up to
speed
Voltage too low at motor
terminals because of line drop
Check transformer and setting of taps. Use higher voltage on
transformer terminals or reduce loads. Increase wire size or reduce
inertia.
Broken rotor bars
Look for cracks near the rings. A new rotor may be required. Have
motor service person check motor.
Wrong motor rotation
Wrong sequence of phases
Switch any two of the three motor leads.
Geareducer noise
Geareducer bearings
If new, see if noise disappears after one week of operation. Drain, flush
and refill Geareducer oil. See Geareducer User Manual. If still noisy,
replace.
Gears
Correct tooth engagement. Replace badly worn gears. Replace gears
with broken or damaged teeth
Unusual fan drive vibration
Loose bolts and cap screws
Tighten all bolts and cap screws on all mechanical equipment and
supports.
Unbalanced driveshaft or worn
couplings
Make sure motor and Geareducer shafts are in proper alignment and
“match marks” properly matched. Repair or replace worn couplings.
Rebalance driveshaft by adding of removing weights from balancing
cap screws. See Driveshaft User Manual.
Fan
Make certain all blades are as far from center of fan as safety devices
permit. All blades must be pitched the same. See Fan User Manual.
Clean off deposit build-up on blades
Worn Geareducer bearings
Check fan and pinion shaft endplay. Replace bearings as necessary.
Unbalanced motor
Disconnect load and operate motor. If motor still vibrates, rebalance
motor.
Bent Geareducer shaft
Check fan and pinion shaft with dial indicator. Replace if necessary.
Fan noise
Blade rubbing inside of fan
cylinder
Adjust cylinder to provide blade tip clearance.
Loose bolts in blade clamps
Check and tighten if necessary
Scale or foreign substance in
circulating water system
Insufficient blowdown
See “Water Treatment” section of this manual.
Water treatment deficiency
Consult competent water treating specialist. See “Water Treatment”
section of this manual.
Cold-water temperature too
warm
(see “Tower Operation”)
Entering wet-bulb temperature
is above design
Check to see if local heat sources are affecting tower. See if
surrounding structures are causing recirculation of tower discharge air.
Discuss remedy with Marley representative.
Design wet-bulb temperature
was too low
May have to increase tower size. Discuss remedy with Marley
representative.
Actual process load greater
than design
May have to increase tower size. Discuss remedy with Marley
representative.
Overpumping
Reduce water flow over tower to design conditions.
Tower starved for air
Check motor current and voltage to be sure of correct contract power.
Repitch fan blades if necessary. Clean louvers, fill and eliminators.
Check to see if nearby structure or enclosing walls are obstructing
normal airflow to tower. Discuss remedy with Marley representative.
Excessive drift exiting tower
Distribution basins overflowing
Reduce water flow rate over tower to design conditions. Be sure hot
water basin nozzles are in place and not plugged.
Faulty drift elimination
Check to see that integral fill, louvers and eliminators are clean, free
of debris and installed correctly. If drift eliminators are separate from
fill, make sure they are correctly installed in place. Clear if necessary.
Replace damaged or worn out components.
