Maintenance techniques on medium voltage contactors.
Maintenance techniques on medium voltage contactors.
(OP)
During a recent shutdown we removed an old GE limit-amp starter from service in order to check the condition of everything. The contacts looked to be in good condition, and we used Scotch-brite to shine them up a bit.
Is Scotch-brite recommended for cleaning any contacts? Low voltage; ie.
Also the stabs for the 4160/120 control transformer had a buildup of black crud on them and were not making a good connection.
Was this crud whats referred to as carbon tracking?
We were unsuccessful in cleaning this off using delicat methods, and had to resort to using a wire wheel to get it off. The silver plating is now worn off, and there are a whole bunch of pits in the stabs where the black crud was. They are making far better contact than before, but I question the "techniques" we used to clean the contacts and the stabs.
When I asked for replacement parts, I was informed that they were obsolete and to do the best we can until a new starter is in the budget. This could be several years. We have not brought this motor online yet, and I'm concerned that we will have problems down the line.
I thoroughly enjoy having the opportunity to work on this large equipment, but finding guidance on some of the inside tricks is difficult. I try to read as much as possible, but for every useful book i find there are 5 useless one.
Is Scotch-brite recommended for cleaning any contacts? Low voltage; ie.
Also the stabs for the 4160/120 control transformer had a buildup of black crud on them and were not making a good connection.
Was this crud whats referred to as carbon tracking?
We were unsuccessful in cleaning this off using delicat methods, and had to resort to using a wire wheel to get it off. The silver plating is now worn off, and there are a whole bunch of pits in the stabs where the black crud was. They are making far better contact than before, but I question the "techniques" we used to clean the contacts and the stabs.
When I asked for replacement parts, I was informed that they were obsolete and to do the best we can until a new starter is in the budget. This could be several years. We have not brought this motor online yet, and I'm concerned that we will have problems down the line.
I thoroughly enjoy having the opportunity to work on this large equipment, but finding guidance on some of the inside tricks is difficult. I try to read as much as possible, but for every useful book i find there are 5 useless one.





RE: Maintenance techniques on medium voltage contactors.
We rebuild these everyday in our shop, buying a new one is a waste of money.
BTW, I stock replacement parts for those. Not a problem, contact me if you still need them.
Scott
www.cbsnuclear.com
RE: Maintenance techniques on medium voltage contactors.
Tom
None of us is as smart as all of us.
RE: Maintenance techniques on medium voltage contactors.
RE: Maintenance techniques on medium voltage contactors.
That paint on silver plating stuff is a temp fix that wont last long. You are on the right track with the tin plating, here are some other solutions.
RE: Maintenance techniques on medium voltage contactors.
Tom
None of us is as smart as all of us.
RE: Maintenance techniques on medium voltage contactors.
Corrosion is definately not a problem at the plant. the small amounts of cement dust present in the substations doesn't seem to bother anything. We clean all the equipment thoroughly quite often.
RE: Maintenance techniques on medium voltage contactors.
Tom
None of us is as smart as all of us.
RE: Maintenance techniques on medium voltage contactors.
I have parts for those
RE: Maintenance techniques on medium voltage contactors.
Tom
None of us is as smart as all of us.
RE: Maintenance techniques on medium voltage contactors.
RE: Maintenance techniques on medium voltage contactors.
RE: Maintenance techniques on medium voltage contactors.
Scott
www.cbsnuclear.com
RE: Maintenance techniques on medium voltage contactors.
scotch brite pads and (if you're good..) needle files are a good way to dress contact buttons and remove scale, tho.. good call on that.
RE: Maintenance techniques on medium voltage contactors.
RE: Maintenance techniques on medium voltage contactors.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Maintenance techniques on medium voltage contactors.
RE: Maintenance techniques on medium voltage contactors.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Maintenance techniques on medium voltage contactors.
We have the large one the guy is standing next to.
When we do something we do it right, we also have a 24 foot Big Ass Fan http://www.bigassfans.com/ to cool the shop
RE: Maintenance techniques on medium voltage contactors.
http://photos.gcbsinventory.com/trailers/