common oem Problems
Brush Restrictions & Carbon Deposits (Figure 1): Many common failures occur in bound up brushes and restricted brush movement. Restrictions in boxes keep the brush from moving freely and can easily be impaired by the box limitations. Carbon deposits form rough edges on the brush boxes stemming from lack of maintenance or dirty conditions.
Arcing: Anytime there is a compromised brush – to – ring connection, there will be an arc, which leads to catastrophic ring fires and costly forced outages. Arcing can happen quickly, and daily visual inspections may not detect the problem right away.
Brush Box Erosion: A poor terminal connection or poor cleaning methods cause erosion, which can sometimes lead to arcing between the brush and the side of the box.
Brush Chatter & Chipped Brushes (Figure 2): If the collector ring surface is rough, then the brush will chatter risking chipped brushes or arcing.
Photographing (Figure 3): Often occurring when the brush to ring connection is compromised and can happen with one or more holders at once. Usually, arcing is also present over time. Photographing is especially difficult to detect with the naked eye.
Keeping collector rings, brushes, and holders healthy leaves the brush to collector ring uncompromised and in good, working condition.
solutions
Online Truing cleans up collector rings at speed and under load with a stone to make them nice, clean, flat, and round again. This method allows generators to continue running reducing unnecessary, costly downtime
EASYchange® Brush Holders were purpose built to reduce brush failures. These holders are tight, tall, and smooth while supporting the entire length of the brush. Personnel can safely rack in – rack out using one hand with the isolated pistol grip design. Maintenance can be done on one brush at a time based on the condition of each brush and holder.
brush condition monitoring
BCM uses a secure, wireless connection to monitor vibration and usable brush length for all brushes. Since the brush is a consumable, plant personnel need to know what’s happening with the brush to ring connection.
The Brush Condition Monitoring system works in conjunction with EASYchange® holders allowing plants to have an integrated system to minimize the risk of failures through the mechanical piece of the holders, and the monitoring system giving advanced detection. This reduces liability and increases plant’s ability to plan maintenance. The two combined, work together to prevent the risk of fires and flash overs. Data is measured and trended on a monitor down by the generator and into the control room.
financial impacts
Estimated Financial Assumptions: Cost of Ring Fire
Estimated Return on Investment: Two Scenarios
Note: All numbers are estimates. The results are illustrative only. Specific risks, costs, and prices will vary. This is not a guarantee of savings nor a guarantee of eliminating risk. Proper maintenance must be performed
automating maintenance
Visual inspections are not always reliable, nor do they catch every failure in the brush holders. Knowing when to check on the brush rigging, and which problems are present is important when planning maintenance.
For more information on Brush Condition Monitoring, click on the image below to view the webinar.
