I like the motor monitoring idea, however here is a different, unrealistic idea:
Heat the air above the column of water in the well. Put a thermistor in the bottom of the well and in the output water at the top of the well. Calculate the temperature difference and from that determine how long...
Thanks for the advice guys. Although cbarn your comment about reading the datasheet was a bit of an assumption.
http://www.national.com/ds/LM/LM7512C.pdf
states that no external components are required.
Are you going to need to be able to provide holding torque or will this thing be in constant motion with a predictable rest state when it is turned off? It may be worth looking into motors with electric brakes, this may also be a safety issue - eg power outage doesn't cause the creation to hit...
I was in the lab today working on a circuit and it wasn't behaving as I expected. I diagnosed the problem as an irregular supply voltage from a 7805 voltage regulator. I am supplying it with 15 volts (also tried 12 volts) and getting 5 volts out. When the resistance of the circuit is low...
I am looking for a single chip that can take a number of inputs (preferably 16) and based on the signal of one digital control input forward a set of 8 of them to outputs.
A made up example to clarify: We have 8 sensors for use in the day and 8 for use in night, and we can only process 8 of...
Sorry, I think my question was misunderstood. When I said companies I meant end-user companies. As in, what does a mill do when they have a 6 year old motor (no warranty) that fails.
I would like to thank everyone for the help I have recieved directly and for the knowledge I have gained by reading other peoples threads.
I am wondering how companies make replace or repair decisons for thier electric motors. As far as I can tell the following would be factors in the...
I would find out all of the nameplate information on some of the motors that had service lifes of 20 years +. Maybe someone decided to buy motors with a SF of 1.0 instead of 1.15 etc.. I would also take current draw readings of the new motors when they are full load to check if a re-evaluation...
Some more details would be helpful. Specs on the motors. How long have they been in service and what is the application.
If the brushes are all wearing evenly then I would look into changing to a different brush that will carry a higher current density in your application. Are all of your...
Was the idle mode a common mode of operation or was it associated with something unusual such as an area shut down?
Have you had a chance to give a visual inspection of the stator to rule out the obvious causes such as contamination/moisture?
If you do not look for electrical faults in your VA...
"wired1 (Electrical) Mar 14, 2003
When was the last time anyone saw a green emergency stop button? "
I think this is a great point. How would you have red as the color for emergency stop and for running? What are peoples experiences with equipment that uses red for running? Do...
The motors are not rewound, if they were we would have core loss tests to check that the core laminations were not damaged.
The motors are currently being repaired in house. We are continuing different things with the bearings and have a new type on order but the feeling of our experienced...
Here is some more information:
Most of the motors are around 1.2A - 1.3A when they are new.
They are typically 1.42A - 1.54A after being rebuilt. At least one is as high as 2.2A.
Those numbers are the averages of all three phases.
It is important that the current draw does not get too high...
These motors due operate in enviroments of high heat. In order to test if it is a core lamination deterioration problem would it suffice to do a core loss test on a new and used motor of the same model?
The problem seems to be independent of bearings and so although we have also thought of the...
I believe the current draw was also high before the bearings were changed. The issue is more that the motors current requirements are increasing with age and it appears to be related to something other than bearings.
I am asking the general question of what would cause the current requirements of a motor at full speed with no load to increase after being in use for a length of time.
Below are more details specific to our problem, although not necessary for the question.
We have a number of specialty 2HP...
I am working on a maintanence/reliability team and I am setting up a database to track motor failures. I was considering tracking the temperature/humidty of the area where a motor fails but I am not sure of the benifits that would have. Any comments on if we will find a direct link between the...