On a vacuum cleaner the part that sees the most wear and tear are the vacuum belts. Every time the vacuum is turned on this goes into motion. Most of the time, this part is operating under normal conditions. Every so often the operator does not see or neglects to see an object that could do harm or damage to the brush attachment. This is when there is a problem. When an item gets lodged between the brush and the housing of the attachment, the brush stops moving. The belts then stops moving but the motor keeps moving. If not caught in time the wheel on the motor will keep spinning until it melts the belt clean through. At this time most operators wish the motor had just stopped and saved the belt, but by the belt breaking money is saved.
The belt on this piece of equipment is the safety device and the disposable part. By wearing out and breaking the belt, this in turn saves the motor from damage. When it comes to time and money, it is easier and cheaper to replace a belt than an electric vacuum motor.
Most vacuum operators are capable of replacing a belt or have someone else close by that can assist them. But most would have a difficult time replacing the motor. Most people would have to take their vacuum to the repair shop and that would take time. If this is in a commercial setting, it would also cost more money because the assigned job could not be completed.
Most operators, either home or commercial generally have a spare belt on hand so the job can be completed. Vacuum Belts are inexpensive and are a known part that will have to be replaced and should be kept on hand.