This manual covers:
-
Cutsforth Brush Holder components
-
Knowing when to change a brush
-
Removing the brush holder
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Inspecting the brush holder
-
Changing the spring and brush
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Remounting the brush holder
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Removing and installing the holder mount
This section displays and lists the components of the Custforth Brush Holder:
|
Part |
Description |
Part |
Description |
|---|---|---|---|
|
A |
Handle |
G |
Upper beam |
|
B |
Terminal mount rib |
H |
10-32 screw – DO NOT ADJUST |
|
C |
Lower beam |
I |
Holder mount |
|
D |
Brush box |
J |
Brush key |
|
E |
Brush Holder |
K |
Release tab |
|
F |
Catch arm |
L |
Brush spring release fingers |
|
M |
Brush catch |
Many factors influence brush wear:
-
Spring pressure
-
Ring condition
-
Current density
-
Atmospheric conditions
-
Presence of contaminants
-
Holder condition
-
Brush grade
Replace brushes before they become too short. Frequently inspect the brushes to determine if they need to be replaced by checking the Brush Change Zone. When the Brush Change Zone reaches the edge of the brush box, it's time to change the brush. Do not let the entire Brush Change Zone wear past the edge of the brush box.
In this example, part A shows a Brush Change Zone on a new brush and part B shows the Brush Change Zone of a brush that is in need of replacement.
WARNING
Brushes should be changed when the wear indicator band reaches the top edge of the box. Cutsforth does not recommend letting brushes wear past the wear indicator point. Doing so can lead to performance problems up to and including a catastrophic failure. Running short brushes may cause the following issues:
-
Decreased spring pressure: Spring pressure is constant through the operational life of the brush but will reduce as the brush is worn past the wear indicator. Decreased spring pressure can result in a poor brush-to-ring connection and elevate the risk of arcing, abnormal ring wear, and increased brush vibration.
-
Increased brush binding: Short brushes are not supported in the brush holder as well as brushes of a proper length and tend to bind in the brush box. The brush leads on short brushes also resist the force of the spring, causing further binding problems. Brush binding will lead to a poor brush-to-ring connection leading to arcing, elevated ring wear, and even a catastrophic failure.
-
Selective action: Short brushes mixed with proper-length brushes can cause uneven current distribution throughout the brushes and lead to overheating problems.