TL;DR
A crusher drive overload trip usually means clinker is packing the inlet or a bearing is failing. Clear the inlet first, then check crusher bearing temperatures before restarting.
What you might see
- crusher motor overload trip
- clinker pile-up at the crusher inlet
- crusher shaft speed sensor fault
- metallic noise from the crusher housing
Likely causes
Clinker inlet backed up and packing the crusher reducing available motor torque
Crusher roller or hammer bearing failure increasing drive resistance
Tramp metal from kiln brick or metallic debris jamming the crusher
Drive coupling worn or damaged absorbing input power
Required tools
- IR thermometer
- Clearing bar or tool
- Radiant-heat PPE
- LOTO kit
Safety first
- Hot clinker in the crusher area. Use radiant-heat PPE and confirm temperature before approaching.
- Lock out the crusher drive and grate before manually clearing the crusher inlet.
Procedure
- 1
Stop the clinker cooler grate and lock out the crusher drive and the cooler grate.
Warning: The crusher area involves hot clinker. Use radiant-heat PPE and confirm the clinker temperature is safe before approaching. - 2
Clear the clinker backup from the crusher inlet using an approved clearing tool. Do not use bare hands.
- 3
Inspect the crusher inlet for visible tramp metal or kiln brick fragments. Remove any detected foreign material.
- 4
Rotate the crusher shaft by hand to check for free rotation. Resistance or grinding indicates a bearing fault.[1]
- 5
Check crusher bearing temperatures with an IR thermometer. Bearings above 80 degC need investigation.[1]
- 6
Inspect the drive coupling for jaw or element wear.
- 7
If the shaft rotates freely and bearings are cool, restart the crusher before the cooler grate and monitor the current on the first run.
Sources
FLSmidth FLSmidth Cross-Bar Clinker Cooler general technical documentation, FLSmidth
FLSmidth clinker cooler crusher maintenance documentation (general)
More guides for FLSmidth FLSmidth Cross-Bar
How to prevent clinker red river and snowman formation on a FLSmidth Cross-Bar cooler
Red river and snowman formation are caused by uneven airflow across the grate. Rebalance the compartment air pressures and adjust the cooler grate speed to spread the clinker bed evenly.
How to inspect and replace worn grate plates on a FLSmidth Cross-Bar clinker cooler
Excessive fall-through dust and hot particles under the grate mean worn or cracked grate plates. Schedule a grate plate inspection at the next kiln stop and replace damaged plates.
Stop fixing the same fault twice.
Dovient turns guides like this into your team's shared playbook, with AI that catches recurring issues before they break the line.