Specifications

TROUBLESHOOTING Document No. DER05103
Effective Date 25 May 07 Page 3 of 5
TROUBLESHOOTING CENTRIFUGE - FULL HYDRAULIC DRIVE
Possible Cause Isolation Procedure & Corrective Action
Failure Mode 3: Centrifuge Has Automatically Shut Down (Cont’d)
Vibration switch tripped. Press and hold vibration switch reset button, and attempt to re-start
centrifuge (refer to Section 4 - Operation). If machine fails to start or shuts
down soon after starting, continue troubleshooting.
Bowl clogged with solids
causing over-torque switch
to trip due to excessive
conveyor torque.
With centrifuge fully stopped, open cover and inspect bowl interior and
conveyor for accumulated solids obstructing rotation. If clogging is evident,
water wash bowl and conveyor until liquid discharge is clear of solids. If
unable to clear bowl of solids, remove rotating assembly, remove conveyor,
and manually clear all solids from the conveyor and bowl interior. After
cleaning, reinstall conveyor in bowl, and reinstall rotating assembly (refer to
Section 5 - Maintenance). Reset overload release and over-torque limit
switch (refer to DER05104).
Drive motor overheated
and/or starter thermal
overloads tripped due to
excessive current draw.
Allow sufficient time for overload to reset, and then press centrifuge starter
RESET button. Press CENTRIFUGE ON button to attempt re-start of
centrifuge. If machine starts, monitor vibration and discharges for any
abnormalities. Shut down centrifuge immediately upon discovering any
abnormal indications such as no solids discharge. Determine cause of
anomaly and correct before attempting to re-start centrifuge.
With power shut down, and CENTRIFUGE ON button pressed, check for
electrical continuity from wire number X1 of CENTRIFUGE ON switch to
ground. If an open circuit is found, check control system components for
continuity to ground at the following wire numbers:
From To If No Continuity
X1 2 Press CENTRIFUGE ON & repeat check
2 4 Press RESET buttons & repeat check
4 5 Press vibration switch reset button
5A 6 Allow motor to cool & repeat check
If any test fails, replace component between affected test points.
If continuity is found at all above points, check for continuity from wire
number 6 to ground. If continuity is not found, replace centrifuge relay CR1.
Check for continuity from each motor winding terminal T1, T2, and T3
separately to ground. Replace motor if continuity is not found from any
winding to ground. If continuity is found across all windings to ground, repeat
all continuity checks to locate defective control system component(s).
Replace defective component(s).
Press centrifuge starter RESET button, and then attempt re-start of
centrifuge. If machine starts, monitor vibration and discharges for any
abnormalities. Shut down centrifuge immediately upon discovering any
abnormal indications such as no solids discharge. Determine cause of
anomaly and correct before attempting to re-start centrifuge.