Request a Quote
Installing a belt on a Republic RB500 Blower

Drive belts play a pivotal role in industrial processes that rely on motors. Because of this, belt breakage can bring operations to a halt, resulting in downtime, maintenance challenges, and additional costs. Careful installation, regular cleaning, and proper operation of the motor can help maintain the integrity of the belt and significantly extend its lifetime.

Centrifugal blowers use a drive belt to harness the spinning motion of the motor, rotate the impeller, and generate pressure and airflow. When troubleshooting the cause of belt breakage, there are many elements to evaluate, from the nuances of misalignment to the impact of tension issues, wear, aging, and environmental conditions. This guide explores the various factors that can contribute to drive belt failure. This list focuses specifically on centrifugal blowers, but these elements affect all mechanical systems that use a drive belt.


Common Causes of Drive Belt Failure

  1. Misalignment

    Any parallel or angular misalignment between the motor and blower pulleys leads to excessive stress on the belts, bearings, and overall system. When the pulley grooves are not aligned, belts experience uneven tension leading to increased wear and tear. This running condition also decreases the efficiency of the blower as additional friction damages belts and converts useful energy potential to wasteful heat. Misalignment can also lead to excessive vibration, adversely affecting bearing life.

    Solution: Use a straight edge to align the pulleys properly. (See videos below.)

  2. Tension Issues

    Both over-tensioning and under-tensioning of belts can contribute to their breakage. Over-tensioning puts excessive stress on the belts and bearings, while under-tensioning can cause slipping and rapid wear.

    Solution: Check the owner’s manual (linked here) to ensure you have the correct tension relative to pulley size.

  3. Belt Wear and Aging

    Belts naturally wear over time, and operating conditions, environmental factors, and maintenance practices influence their lifespan. Old or worn-out belts are more prone to breaking. Blower drive belts should be inspected monthly for signs of aging, such as cracking, brittleness, or changes in color.

    Solution: New belts can be purchased through Republic Manufacturing or a local representative. Refer to the owner’s manual (linked here) for factory-recommended preventative maintenance.

  4. Foreign Objects and Debris

    Foreign objects, such as tools or debris, can get lodged between the belt and pulley, causing sudden stress and leading to belt breakage.

    Solution: Increase frequency of cleaning or install an enclosure around the blower to protect it.

  5. Imbalance in the Bearing Housing

    An imbalanced blower spindle can result in excessive vibration and an uneven distribution of tension in the belt. This can lead to increased stresses and the eventual failure of the belt. Balancing the blower components is essential to avoid this kind of belt failure.

    Solution: All Republic blower units are balanced to an ISO G1 grade at the factory. Contact your local representative or Republic to have your bearing housing re-balanced.

  6. Excessive Load or Overloading

    If the blower is subjected to loads beyond its design capacity, it can strain the belts and lead to breakage. Ensure that the blower system is appropriately sized for the intended application.

    Solution: Contact your local representative or Republic to ensure your system is properly sized.

  7. Pulley Problems

    Worn or damaged pulleys can cause uneven tension distribution and lead to belt breakage.

    Solution: Regular inspection of pulleys and prompt replacement of damaged components is crucial. New belts and pulleys can be purchased through Republic Manufacturing or your local representative.

  8. Environmental Conditions

    Harsh environmental conditions, such as extreme temperatures, humidity, or chemical exposure, can accelerate belt degradation and increase the likelihood of breakage.

    Solution: Increase frequency of cleaning or install an enclosure around the blower to protect it.

  9. Installation Errors

    Incorrect installation of belts, pulleys, or the blower itself can result in misalignment and tension issues, leading to premature belt breakage.

    Solution: Contact your local representative or Republic to confirm the correct belt is installed.

Need a new belt for your centrifugal blower? Find belts for your blower model here.



We recommend keeping spare belts in stock to reduce downtime in the case of breakage and to avoid continued use of a worn or damaged belt while waiting for a replacement. You can find the part number stamped on the flat side of the belt or printed in the owner’s manual (above).


Video Guides

The following videos provide in-depth guides to properly changing your belt.

RB800, RB1200HC, RB2000, RB2400, RBX-150, RBX-250, RBX-400:

Belt alignment check: 0:48