The primary crusher is the first piece of equipment limestone touches after blasting, and it has the least tolerance for an unplanned stop of anything upstream of the kiln. One missed bearing temperature reading, one unlogged motor current spike, or one discharge chute blockage building undetected can halt raw material feed to a 5,000 TPD line for 12 hours or longer. Sign up to turn this checklist into shift-level readings with automatic trend tracking.
Why It Matters
A crusher rarely fails without warning. Bearing heat, current fluctuation, and chamber noise all show up before the stop, but only if someone reads and logs them. Pre-start checks catch what happened overnight, lube leaks, chamber debris, toggle wear, that running checks alone will miss.
Critical Checks At A Glance
Bearing Temperature
Logged both ends every shift, a sudden rise signals imminent failure
Motor Current
Abnormal spikes indicate feed size issues or a developing blockage
Discharge Chute Flow
Confirmed clear with steady flow to the downstream conveyor
Vibration & Noise
Steady low-pitched sound expected, metallic clanking means stop now
Lubrication
Correct dosage matters, both under and over-greasing damage seals
Dust Suppression
Spray systems and seals intact, covers not detached or leaking
Pre-Start Checklist
Confirm all LOTO tags removed and no open work orders hold active isolation on this crusher
Inspect the crushing chamber for debris, oversized material, or anything left from the previous shift
Check for overnight lube leaks under the frame and at seal points
Visually inspect toggle plate and jaw or liner wear before issuing the start command
While-Running Checklist
Log rotor bearing temperature at both ends, warm to the touch is normal, a sudden rise is not
Watch the ammeter for a stable reading, fluctuation points to uneven feeding or a chamber blockage
Confirm discharge particle size is uniform and the chute is flowing to the downstream conveyor
Listen for a steady low-pitched sound, any metallic clanking means stop and inspect for internal faults
Turn Readings Into A Trend Record
OxMaint logs shift-level bearing temperature, motor current, and chute flow, pre-configured for cement plant primary crushers with auto-generated work orders. Sign up for a free trial to explore it on your own crusher, or book a demo to see it configured for your plant.
Stop The Crusher Immediately If You See This
Metallic clanking or any sound that breaks from the normal steady, low-pitched operating tone
A sudden bearing temperature rise, this is the clearest early sign of poor lubrication or imminent failure
Ammeter readings swinging instead of holding steady, feed or blockage issue developing in the chamber
Discharge chute backing up or flow to the downstream conveyor stopping entirely
Symptom, Likely Cause & Response
| Symptom |
Likely Cause |
Response |
| Motor current spike |
Oversized feed material or chamber blockage |
Reduce feed, inspect chamber before continuing |
| Bearing running hot |
Poor or excessive lubrication, seal wear |
Log temperature trend, schedule lube check |
| Discharge blockage |
Caked material buildup in chute or opening |
Clear chamber and chute with power off before restart |
| Uneven discharge size |
Jaw or liner wear, incorrect discharge setting |
Inspect wear parts, adjust discharge opening |
The Takeaway
A primary crusher gives clear warning before it stops, heat, current, sound, flow. The checklist only works if every reading gets logged and compared against yesterday's, not just glanced at and forgotten by the next shift.
Frequently Asked Questions
Q
Why does a single missed inspection matter so much on a primary crusher?
It's the first equipment raw material touches after blasting, so everything downstream depends on it staying up. A missed bearing reading or unlogged current spike can build undetected into a stop that halts feed to a 5,000 TPD line for 12 hours or longer.
Q
What's the difference between pre-start and while-running checks?
Pre-start checks catch what happened overnight, lube leaks, chamber debris, toggle wear, that would only surface once the crusher is already running. While-running checks track live behavior, bearing temperature, motor current, and sound, that changes shift to shift under load.
Q
Can a CMMS actually catch a motor current spike before it becomes a stop?
Yes. Logging current readings against a baseline every shift means an abnormal spike gets flagged and compared automatically, instead of relying on someone noticing an ammeter needle move. That's what turns a blockage into a planned clear-out instead of an emergency stop.
Log Every Crusher Reading Automatically
OxMaint captures bearing temperature, motor current, discharge chute flow and lubrication checks shift by shift, with auto-generated work orders when a reading crosses baseline. Sign up for a free trial to explore it on your own crusher, or book a demo to see it configured for your plant.
