Rock Products - The Leading Voice of the Aggregate Industries.


By Mark S. Kuhar

22 Troubleshooting 400

Rip-detector installed.

Compared to practices from more than a century ago, today’s modern technology helps improve production much more efficiently. However, sometimes new technology and methods can malfunction, causing procedures to abruptly halt until the problem is resolved. In the long run, these types of problems will cost you time and money.

Aggregate conveyor belts and equipment are susceptible to different types of maintenance issues over time. Here are some common areas of concern with conveyor belts and how to quickly repair them while on the job, courtesy of the experts at Applied Conveyor Technology Inc.

Belt Slipping Upon Start
  • If this is a new problem, it’s possible that belt tension is to blame. Consider these options, which vary from one situation to another.
  • Check the drive pulley to ensure that there is no build up. Once this has been done, increase belt tension as well as the amount of belt wrap on the drive pulley.
  • If the drive pulley is not the area of concern, your belt tension may just be a little off. Manually reset the tension requirements for the load; although remember that this requires you to understand how much weight or tension is necessary to pull the material. At this point, you can either increase weight on gravity or increase tension at screw take-up.
  • There are multiple pulleys that help to move a product down the conveyor. Check all pulley lags. If they are worn or close to being inoperable, replace them immediately. While you are checking pulley lags, also see if they are at the appropriate diameters for the belt distance and size.
  • If your counter weight is too strong, you will suffer belt slips because of a lack of tension in the conveyor belt. A simple fix is to shorten the belt and then re-splice it.
  • If your pulleys and weight requirements are correct, it may be an error due to the mechanical generator. You will need to either consider a soft start or try adjusting the horsepower.

All of the above tips also assist if there is slipping while the machinery is in operation. However, there are also a few additional places to check for quick fixes:

  • Check your belt idlers. If they are frozen, you will need to replace the idlers. Follow up with routine lubrication, proper cleaning and alignment adjustments.
  • If material is building up at the pulley face, clean the system and install proper conveyor belt cleaners. You may also want to examine the skirting and install material scrapers to keep the product flowing through evenly, which will reduce the risk of buildup in the future.
Belt Running on One Side
23 Troubleshooting 362

Effects of off-center loading.

This is a common dilemma associated with aggregate materials, and it is usually a sign that there is a problem with the idlers in a particular area of the belt train. Locate where the belt starts running to the side, then replace any frozen idlers.

You also want to make certain that you conduct regular maintenance on all idlers, including lubrication, cleaning, and alignment when necessary. Other things to take into consideration:

  • Is your pulley system as well as its idlers square with the belt’s center line? If not, readjust them. Also verify that the conveyor frame is square, level and properly supported.
  • Is material starting to build up when in operation? If so, install scrapers or brushers to help clean the belt while it’s in use.
  • In case of idler strands, you will want to check that everything is properly centered and aligned.
Loaded Belt Not Tracking

On rare occasions the belt will make good contact with idlers when empty but begins to malfunction when loaded. You will need to readjust the idlers for belt contact when loaded with weight.

Another common problem is when the load chutes are off-center. Realign the load chutes if necessary and also ensure that they drop material in the same direction that the belt travels.

Belt Stretching Excessively

If your belt is overstretched when in use, you may perhaps have too much tension in your operation. Test that you have the right tension belt for the load travel. Aside from completely replacing the tension belts, some steps to counter this issue include:

  • Decreasing the load while increasing the speed of the drive motor.
  • Adjusting or applying soft start motor controls.
  • Inspecting to make sure that your counter weight and screw take-up are at adequate levels.
  • If applicable, decrease the angle of incline while increasing the tension rating and number of belt plies.
Belt Stalls or Jerks
23 Troubleshooting2 400

Bad wear on a conveyor belt.

If your belt is stalling or jerking, your slack slide tension is off. Increase your take-up position, and also look at your drive pulleys and adjust the lags if necessary. It may also help to put a snub pulley behind the drive pulley to help increase the belt wrap.

If none of the above are problems you face, you may want to ensure that the mechanical fasteners are operating correctly. Damaged covers can also delay production, so you will need to check that you’re using the right cover for your type of loads.

  • Spilled oil or grease can cause covers to swell or become soft. A major point of contamination is over-greased bearings.
  • Heat affects covers and causes them to crack. Chemical damage can also cause hardening and cracking. If covers are not in use, store them indoors to prevent damage from UV rays and the elements.
  • Always ensure that you are using the right compound for your operation. This will help offset any potential costly setbacks.

There are many effective solutions if you are experiencing mining conveyor equipment problems. If you experience production errors that have not been mentioned here, contact your equipment manufacturer for further troubleshooting tips and advice.

Information for this article courtesy of Applied Conveyor Technology Inc., which has distributed equipment to aggregate companies nationwide for almost 25 years. Visit them on the web at