| S.No | Code | Fault | Cause | Corrective Action |
|---|---|---|---|---|
| 1 | CN-01 | Conveyor runs to one side at given point on structure | Buildup of material on idlers | "Remove accumulation; improve maintenance; Install scrapers or other cleaning devices" |
| Sticking idlers | Free idlers and improve maintenance and lubrication | |||
| Idlers or pulleys out-of-square with center line of belt | Readjust idlers in affected area | |||
| Conveyor frame or structure crooked | Straighten in affected area | |||
| Idler stands not centered on belt | Readjust idlers in affected area | |||
| Structure not level | Level structure in affected area | |||
| 2 | CN-02 | Particular section of belt runs to one side at all points on the conveyor | Belt not spliced/joined squarely | Remove affected splice and re-splice |
| Bowed belt | "For a new belt, this condition should disappear during break-in; in rare instances, belt must be straightened or replaced; | |||
| Check storage and handling of the belt rolls" | ||||
| 3 | CN-3 | Belt runs to one side for long distance or entire length of the conveyor | Belt running off-center around the tail pulley and through the loading area | Install training idlers on the return side prior to the tail pulley |
| Off-center or poor loading | "Adjust chute to place load on center of belt; Discharge material in direction of belt travel at or near belt speed" | |||
| Buildup of material on idlers | "Remove accumulation; Improve maintenance; Install scrapers or other cleaning devices" | |||
| Idlers or pulleys out-of-square with center line of the belt | Readjust idlers in the affected area | |||
| Conveyor frame or structure crooked | Straighten in affected area | |||
| Idler stands not centered on belt | Idler stands not centered on belt Solutions: | |||
| 4 | CN-4 | Belt runs off at the tail pulley | Belt running off-center around the tail pulley and through the loading area | Install training idlers on the return side prior to the tail pulley |
| Material spillage and buildup | "Improve loading and transfer conditions; Install cleaning devices; Improve maintenance" | |||
| Idlers or pulleys out-of-square with center line of the belt | Readjust idlers in the affected area | |||
| 5 | CN-5 | Belt runs off at the head pulley | Pulley lagging worn | Replace the pulley lagging |
| Material spillage and buildup | Improve loading and transfer conditions; install cleaning devices; improve maintenance | |||
| Idlers or pulleys out-of-square with center line of the belt | Readjust idlers in the affected area | |||
| Idler stands not centered on the belt | Readjust the idlers in the affected area | |||
| 6 | CN-6 | Belt slip | Insufficient traction between the belt and pulley | "Lag the drive pulley; Increase the belt wrap; Install belt-cleaning devices" |
| Pulley lagging worn | Replace the pulley lagging | |||
| Counterweight too light | Add counterweight or increase the screw take-up tension to value determined from calculations | |||
| Material spillage and buildup | Improve loading and transfer conditions | |||
| Sticking idlers | Free idlers and improve maintenance and lubrication | |||
| 7 | CN-7 | Belt slip on starting | Insufficient traction between the belt and pulley | Lag the drive pulley; increase the belt wrap; install belt-cleaning devices |
| Counterweight too light | Add counterweight or increase the screw take-up tension to value determined from calculations | |||
| Pulley lagging worn | Replace the pulley lagging | |||
| 8 | CN-8 | Excessive belt stretch | Improper belt installation, causing excessive belt stretch | "Pull belt through the counterweight with tension equal to at least the empty running tension; Break belt in with mechanical fasteners" |
| Improper initial positioning of the counterweight in its carriage, causing apparent excessive belt stretch | Check the Continental ContiTech Handbook of Belting for the recommended initial position | |||
| Tension too high | "Increase belt speed at same tonnage; Reduce tonnage, maintain same belt speed; Reduce friction with better maintenance and replacement of damaged idlers; Decrease tension by increasing arc of contact or go to lagged pulley; Reduce the counterweight to minimum amount" | |||
| System under belted | Recalculate belt tensions and select proper belt | |||
| 9 | CN-9 | Grooving, gouging or stripping of the top cove | Skirt boards improperly adjusted or wrong materia | "Adjust the skirt board supports to a minimum of 1" between metal and belt, with gap increasing in direction of belt travel. Use skirt board rubber, not old belt." |
| Belt spanking down under load impac | Install cushion idlers | |||
| Material hanging up in or under the chute | "Improve loading to reduce spillage; Install baffles; Widen chute" | |||
| Impact of material on the belt | "Reduce impact by improving the chute design Install impact idlers" | |||
| 10 | CN-10 | Excessive top cover wear, uniform around the belt | Dirty, stuck or misaligned return rolls | "Remove accumulation Install cleaning devices Use self-cleaning return rolls Improve maintenance and lubrication" |
| Cover quality too low | Replace with a belt of heavier-cover gauge or higher-quality rubber | |||
| Material spillage or buildup | "Improve loading and transfer conditions; install cleaning devices; Improve maintenance" | |||
| Off-center loading or poor loading | Adjust the chute to place the load on the center of the belt; Discharge material in the direction of belt travel at or near the belt speed | |||
| Excessive sag between idlers causing the load to work and shuffle on the belt as it passes over idlers | "Increase tension if unnecessarily low; >Reduce idler spacing" | |||
| 11 | CN-11 | Severe pulley cover wear | Sticking idlers | "Free idlers; Improve maintenance and lubrication" |
| Slippage on the drive pulley | "Increase tension through screw take-up or add counterweight; lag the drive pulley; Increase arc of contact" | |||
| Material spillage and buildup | "Improve loading and transfer conditions; install cleaning devices; Improve maintenance" | |||
| Material trapped between the belt and pulley | Install plows or scraper on return run ahead of tail pulle | |||
| Bolt heads protruding above lagging | "Tighten bolts; Replace lagging; Use vulcanized on lagging" | |||
| Excessive forward tilt of trough rolls | Reduce forward tilt of idlers no more than 2 degrees from vertical | |||
| 12 | CN-12 | Longitudinal grooving or cracking of bottom cover | Sticking idlers | Free idlers and improve maintenance and lubrication |
| Slippage on the drive pulley | "Increase tension through screw take-up or add counterweight; lag the drive pulley; Increase arc of contact" | |||
| Material spillage and buildup | "Improve loading and transfer conditions; install cleaning devices; Improve maintenance" | |||
| Pulley lagging worn | Replace pulley lagging | |||
| 13 | CN-13 | Covers harden or crack | Heat or chemical damage | Use the belt designed for the specific condition |
| Improper storage or handling | Contact us for proper storage and handling instruction | |||
| 14 | CN-14 | Covers swell in spots or streaks | Spilled oil or grease; over-lubrication of idlers | "Improve house keeping; >Reduce quantity of grease used; check grease seals" |
| 15 | CN-15 | Belt breaks at or behind fasteners; fasteners pull out | Fastener plates too long for pulley size | Replace with smaller fasteners; increase pulley size |
| Wrong type of fastener; fasteners too tight or too loose | Use proper fasteners and splice technique; set up schedule for fastener inspection | |||
| Tension too high | Increase belt speed, same tonnage; reduce tonnage, maintain same belt speed; reduce friction with better maintenance and replacement of damaged idlers; decrease tension by increasing arc of contact or go to lagged pulley; reduce the counterweight to minimum amount | |||
| Heat or chemical damage | Use belt designed for specific conditions | |||
| 16 | CN-16 | Vulcanized splice separation | Belt improperly spliced | Re-splice using proper method as recommended by Continental ContiTech |
| Pulleys too small | Use larger-diameter pulleys | |||
| Tension too high | "Increase belt speed, same tonnage; Reduce tonnage, maintain same belt speed; Reduce friction with better maintenance and replacement of damaged idlers; Decrease tension by increasing arc of contact or go to lagged pulley; Reduce the counter-weight to minimum amount" | |||
| Material trapped between belt and pulley | Install plows or scrapers on return run ahead of the tail pulley | |||
| Improper transition between troughed belt and terminal pulleys | Adjust in accordance with our recommendations | |||
| 17 | CN-17 | Excessive edge wear, broken edges | Off-center loading or poor loading | Adjust chute to place the load on the center of the belt; Discharge material in direction of belt travel at or near belt speed |
| Material spillage and buildup | "Improve loading and transfer conditions; install cleaning devices; >Improve maintenance" | |||
| Belt hitting structure | Install training idlers on carry and return run | |||
| Bowed belt | For a new belt, this condition should disappear during break-in; In rare instances, the belt must be straightened or replaced; Check storage and handling of belt rolls | |||
| 18 | CN-18 | Transverse breaks at belt edge | Belt edges folding up on structure | Install limit switches; provide more clearance |
| Improper transition between troughed belt and terminal pulleys | Adjust transitions in accordance with Continental ContiTech Handbook of Conveyor and Elevator Belting | |||
| Severe convex (hump) vertical curve | Decrease idler spacing in vertical curve; increase curve radius; consult us for assistance | |||
| 19 | CN-19 | Short breaks in carcass parallel to belt edge, star breaks in carcass | Impact of material on the belt | Reduce impact by reducing the chute design; install impact idlers |
| Material trapped between belt and pulley | Install plows or scrapers on return run ahead of tail pulley | |||
| 20 | CN-20 | Ply separation | Insufficient transverse stiffness | Replace with the proper belt |
| Pulleys too small | Use larger-diameter pulleys | |||
| Heat or chemical damage | Use the belt designed for specific condition | |||
| 21 | CN-21 | Carcass fatigue at idler junction | Improper transition between troughed belt and terminal pulleys | Adjust transition in accordance with Continental ContiTech Handbook of Conveyor and Elevator Belting |
| Severe convex (hump) vertical curve | Decrease idler spacing in curve; increase curve radius | |||
| Excessive forward tilt of troughed rolls | Reduce forward tilt of idlers to no more than 2 degrees from vertical | |||
| Excessive gap between idler rolls | Replace idlers; replace with heavier bel | |||
| Insufficient transverse stiffness | Replace with the proper belt | |||
| Excess gap between idlers, causing load to work and shuffle on the belt as it passes over idlers | Increase tension if unnecessarily low; reduce idler spacing | |||
| 22 | CN-22 | Cover blisters or sandblisters | Cover cuts or very small cover punctures allow fines to work under the cover and propagatebetween the cover and carcass | Make a vulcanized spot repair or a self-curing repair |
| Spilled oil or grease, over lubrication of idlers | Improve housekeeping; reduce quantity of grease used; check grease seals |
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