Keep in mind that carbon dust will accumulate between the bars of the commutator and can produce a potential for a bar-bar short. A well-balanced armature is also recommended to prevent the brushes from causing any unnecessary damage to the commutator.
A commutator that is out of round can also lead to potential high bars, which can damage the brushes and cause excessive arcing where the brush contacts the copper bars. If the eccentricity of the commutator is not acceptable, you could end up with broken brushes and/or brush springs. It is very important to keep proper maintenance schedules to ensure the commutator stays round without run-out on the surface. Some larger DC motors may be able to be machined onsite to prevent unnecessary extraction of the motor. The segments are insulated between bars with a molding mica. The bars on a commutator must be maintained by way of machining the segmented commutator bars true. Like carbon brushes, the commutator requires maintenance from time to time. Setting the neutral can be adjusted and performed onsite when applicable. Changing loads can be difficult to get right.
Keeping the brushes in a neutral position can prevent excessive arcing while under load. To do this, you need to position the adjacent brushes in an area on the commutator outside or in between the polarity reference of the armature coils being energized with voltage across the brushes. The rack or yoke component must be properly adjusted to what is called “neutral” position. A very low megohmmeter reading can notify the DC drive to shut down the power to warn of a potential to ground. A good way to prevent carbon build up is to use compressed air to help remove any lingering dust from within the motor. Carbon dust is destructive to the insulation and must be maintained by way of removing the dust within the motor to prevent low megohmmeter readings.
#DC MOTOR WINDING RESISTANCE FULL#
It is also important to keep proper, constant pressure on the brush to the commutator to deliver the full current density at the point of contact in order to alleviate premature wear on the brushes. A carbon brush survey could be of value to investigate the proper grade of brush for each of your applications. This issue can wear the commutator bars to a point of irreversible damage. When an applied load is not consistent and the motor has the wrong grade of brushes, the carbon brushes can wear out prematurely, causing carbon dust to accumulate within the motor. This is very important for brush conductivity on the commutator and the current density so the brushes can maintain a certain lubricity when contacting the commutator under load. Carbon BrushesĭC motors must be applied with the proper amount of load. This article will help you troubleshoot six of the most common DC motor issues. DC motor users in the manufacturing sector know all too well the headaches that can come along with troubleshooting issues. Though DC Motors are simple machines, proper and timely maintenance is important to lengthen the motor and facility’s lifespan. By Mike Switzer, Product Line Manager 6 Common DC Motor Issues