Sterlco ST500 Series Central Granulator - Manual (Page 81)

81
TROUBLESHOOTING
SECTION 7-3
Mechanical Faults
PROBLEM
Mechanical Faults
PROBABLE CAUSE REMEDY
A. Bearing overheating 1. Excessive wear on the V-
Belt drive
1. Check belt tension and
adjust as necessary
2. Inadequate lubrication 2. Check lubrication frequency
and the recommended
lubricants in motor and rotor
bearings
3. Dirt/Contamination in
bearing
3. Eliminate source of
contamination
B. Visible cracks in knives 1. Incorrect grinding
procedure or incorrect
grinding wheels in use
1. Check grinding procedures
and contact a STERLING
Service Engineer
C. Knives moving on seats 1. Uneven knifes seat surfaces 1. Clean knife seats to provide
maximum bearing surface
2. Loose knife screws 2. Tighten to correct torque,
per section 4
3. Stretched knife screws 3. Knife screws should not be
used more than six times.
Renew them if there is
evidence of stretching
D. Knives breaking 1. Possibly due to cracks
caused by incorrect grinding
1. Refer to problem B.
“Visible cracks in knives”
(above left)
2. Abnormally heavy material 2. Contact a STERLING
Service Engineer
3. Contaminated input
material
3. Inspect the material for
contaminates and foreign
matter
E. Excessive knife wear 1. Open knife setting 1. Reset as detailed in
alternate material
2. Abrasive materials 2. Contact a STERLING
Service Engineer
F. Screens wearing 1. Incorrectly seated 1. Check that the screen is
seated correctly and fully on
its cradle
2. Abrasive materials being
granulated
2. Obtain special alloy or heat
treated screens