electricpete
Electrical
- May 4, 2001
- 16,774
This is the same family of vertical motors referred to in other motors recently - Westinghouse Lifeline D frame 5800 and frame 5000 series.
We have 18 of these motors - here is an overall picture of one for reference (ignore the annotations left over from another thread)
If you look through the discharge air baffles at the outside of the stator core, on 8 of the 18 machines you can see something similar to a crevice which goes all the way from top to bottom. Sometimes in a wandering vertical line, sometimes in a relatively straight vertical line. Always when you look close you see a jagged patter similar to this:
Here's another picture not quite as good as the last:
We can't easily get a better view at this time to see how deep the crevice is, although we may have some opportunity to pull that cover in the near future.
From the appearance (no fresh metal, paint inside the crevice), it looks like it has been there a long time - perhaps since initial manufacture. The most likely scenario is that this was a notch which was present on the outside of each of the laminations prior to assembly. But for some reason these notches (if that's what they are) when assembled don't line up in any regular pattern.
By the way, these motors have operated well during intermittent duty for 20 years. No vibration problems, no abnormal currents, no abnormal temperautres on stator rtd's, no abnormal insulation test results
Has anyone ever seen anything like this? Can you explain why the laminations might be made with notches like this and why these notches might show up in this strange pattern (not lined up)
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Eng-tips forums: The best place on the web for engineering discussions.
We have 18 of these motors - here is an overall picture of one for reference (ignore the annotations left over from another thread)
If you look through the discharge air baffles at the outside of the stator core, on 8 of the 18 machines you can see something similar to a crevice which goes all the way from top to bottom. Sometimes in a wandering vertical line, sometimes in a relatively straight vertical line. Always when you look close you see a jagged patter similar to this:
Here's another picture not quite as good as the last:
We can't easily get a better view at this time to see how deep the crevice is, although we may have some opportunity to pull that cover in the near future.
From the appearance (no fresh metal, paint inside the crevice), it looks like it has been there a long time - perhaps since initial manufacture. The most likely scenario is that this was a notch which was present on the outside of each of the laminations prior to assembly. But for some reason these notches (if that's what they are) when assembled don't line up in any regular pattern.
By the way, these motors have operated well during intermittent duty for 20 years. No vibration problems, no abnormal currents, no abnormal temperautres on stator rtd's, no abnormal insulation test results
Has anyone ever seen anything like this? Can you explain why the laminations might be made with notches like this and why these notches might show up in this strange pattern (not lined up)
=====================================
Eng-tips forums: The best place on the web for engineering discussions.