Direct current (DC) motors are not commonly specified for new projects in the industrial setting anymore, but there are still many of them in service with our Pulp and Paper and Steel customers in the Pacific Northwest. Much more complex than AC induction motors, direct current (DC) motors require regular maintenance to continue operating at peak performance. Northwest Motor Service has a DC motor maintenance program designed to keep these complex motors in peak condition.
The unique feature of the DC motor is commutation. In a DC motor the commutator applies electric current to the armature windings through carbon brushes. The current direction reverses in the winding each half-turn, creating a steady rotating force (torque). Many DC motors were installed in applications where speed/process control was necessary prior to the advent of Variable Frequency Drives (used with AC motors). The downside is that carbon brushes are a wear item and must be inspected and replaced regularly.
Our DC Motor Brush Maintenance program addresses the following items:
- Routine static testing is performed on an annual basis to test the motor windings.
- Brushes are checked for wear and replaced per OEM specifications.
- Commutator health is documented and photographed to allow for continued monitoring.
While this is a relatively straightforward program, we have found that many of our customers lack the resources or expertise to do this work on outage days. If routine brush maintenance is something that your facility could benefit from please contact Steve Warren by calling our office at 360-425-8700 for more information.
Spencer Wiggins, President
Northwest Motor Service