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glenn1340
25-07-2014, 04:22 AM
I`m sure everyone here has been to a motor that had noisy bearings or had tripped due to the bearings collapsing. I`ve been to many but have never had to watch one actually fail.
The site I`m on has a boiler fed by a 110kw water feed pump at 44 bar. Due to cost cutting the standby pump has been out of service for over a year. A few weeks ago the remaing one failed with a drive end bearing overheating. Much panic ensued as we only have one boiler and the entire site shuts down when the bolier fails; the motor was taken off the other pump and fitted in place of the bearing failure one. Halfway into a twelve hour night shift I thought the motor NDE was starting to be noisy but I put this down to listening just a bit to hard. One hour later I knew there was a problem developing as the noise was definitely there. If we had another pump I`d have switched over but I was stuck with this one. Over the next three hours it became increasingly louder so by 4.30 am I was phoning people up to inform them of impending shutdown (we have to do this as a procedure) 4.45: smoke was filling the plant room and I saw in was coming from the NDE along with loud screeching. I shut down the pump along with the boiler. A new motor was fitted and the boiler on line again fifteen hours later. So much for cost cutting!
The reason for posting this is I often read that bearings usually fail over a period of months (I`ve asked for bearing monitoring but once agian "cost cutting" gets in the way) so it was quite an experience to be present during the rapid failure of a bearing.

HVACRsaurus
25-07-2014, 05:28 AM
Thanks for sharing.

Do the people in charge of the cost cutting get a pay rise because of the costs they have cut?

Grizzly
25-07-2014, 05:44 AM
Thanks for sharing.

Do the people in charge of the cost cutting get a pay rise because of the costs they have cut?
Of course they do!
Engineers plan for the future, Others plan for now!
Glenn now is the time to ask for a stand-bye pump and who ever says no,
Ask them to confirm in writing that you are not authorised to get one.
After that you are covered. its a brave or stupid fellow that signs your disclaimer.
Grizzly

PRESS
25-07-2014, 06:05 AM
On one of our site facilities and property managers get bonusses for cutting costs. thats how difficult it is engineers to plan.

mikeref
25-07-2014, 08:11 AM
Pump motor sat for a year and lubricant moved down from the upper side of bearings, leaving a good portion of the bearing dry and exposed to moisture and surface rust. Most likely some lubricant leaked out.

Initial spin up of your motor left the bearings chewing on a combination of excess friction and heat, metal fragments and diluted lubricant.....I guess you figured that much anyway :)
Interesting reading so thanks for sharing.