Motor problem
- Thread starter leeco
- Start date
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You may have to measure the resistance of the windings, between each other, if it is a delta, if there are 3 sets of seperate windings witha 4th common connection then measure each windings resistance against the common connection,
There should be same reading between all three sets of windings, for example if you have 3 terminals let us call them A, B, C, and they are in a delta configuration, that means they do not have a 4th common connection,
so measure resistnace as betwen :
A&B
A&C
B&C
They should all be the same and if they differe then you have a likely problem with the windings, they can be short circuit as well as open circuit windings, it is likely yours have gone open or elose you would be seeing lot of smoke from it if it was shorted out one of the windings.
There should be same reading between all three sets of windings, for example if you have 3 terminals let us call them A, B, C, and they are in a delta configuration, that means they do not have a 4th common connection,
so measure resistnace as betwen :
A&B
A&C
B&C
They should all be the same and if they differe then you have a likely problem with the windings, they can be short circuit as well as open circuit windings, it is likely yours have gone open or elose you would be seeing lot of smoke from it if it was shorted out one of the windings.
They all measure the same resistance.
This might sound daft but as the C/U is right next to the table and it has been handy using the MCB as a switch to turn the motor on and off could this be the reason why its not working right? I know a MCB is not a switch but I have been using it as one.
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MCB is effectively a switch, except it knocks itself off when the current exceeds the designed limit, if you suspect something might be up, check the mains voltage coming out of it with a multimeter. You should really be using a proper switch as the MCB's aren't really designed for cyclic operation, and may thus have a reduced life, just my guess though.
out of curiousity, may I ask what does this motor viberate? and what it is used for and if my guess is a table, whats the purpose of it?
in the picture you posted,i can see the motor is suspended or bolted underside of the table, in which direction did the table viberate more, i.e. up and down or sideways?
could there be some restriction to the moving part of the table, such that it is no longer able to move freely and hence the viberations are being hampered?
out of curiousity, may I ask what does this motor viberate? and what it is used for and if my guess is a table, whats the purpose of it?
in the picture you posted,i can see the motor is suspended or bolted underside of the table, in which direction did the table viberate more, i.e. up and down or sideways?
could there be some restriction to the moving part of the table, such that it is no longer able to move freely and hence the viberations are being hampered?
Going by Leeco's post showing a photograph on top of page 2, where his motor is shown as having been converted from a 3 phase to a single pahse, with obviously reduced torque, this is how his one has been wired up:
Remove the common bar joining the 3 top terminals and then bridge terminals
W1 with V2
V1 with U2
U1 with W2
Then wire up a 10uF 400V Motor starting capacitor across V1 and U1 and apply 230-240V ac Live to W1 and Neuteral to V1 (V1 is also common to the capacitor)
This should make your motor run, and it may run in a wrong direction to the one you want, in which case you may need to take your neuteral from V1 and instead attach it to U1, hopefully this will now spin it in the dfirection you want.
also quite important that you earth the motor case, and use an appropriate fuse for safety, once done stand back, make sure the motor is secure properly and won't tip over etc when switched on with its opposite reaction force, stand well back, cross your fingers and switch on! voila!
Please only do this if you feel confident and know how to handle electrical things, and in particularly motors, as they can be dangerous due to spinning shafts and pulleys, so keep yourself at distance from moving things, don't forget the earthing is most important, keep all pets etc away from the area, finally it is all at your own risk, I take no responsibility for anything going wrong, once you have carried out initial testing and are confident that the motor will run cool and happy, then after that you don't really have any problem, as long as it is doing its job, and has enought torque and power and runs as expected, and not getting too hot or starts to smoke, and don't allow any motor to stall, as it will suerly burn out in a puff of smoke!
Remove the common bar joining the 3 top terminals and then bridge terminals
W1 with V2
V1 with U2
U1 with W2
Then wire up a 10uF 400V Motor starting capacitor across V1 and U1 and apply 230-240V ac Live to W1 and Neuteral to V1 (V1 is also common to the capacitor)
This should make your motor run, and it may run in a wrong direction to the one you want, in which case you may need to take your neuteral from V1 and instead attach it to U1, hopefully this will now spin it in the dfirection you want.
also quite important that you earth the motor case, and use an appropriate fuse for safety, once done stand back, make sure the motor is secure properly and won't tip over etc when switched on with its opposite reaction force, stand well back, cross your fingers and switch on! voila!
Please only do this if you feel confident and know how to handle electrical things, and in particularly motors, as they can be dangerous due to spinning shafts and pulleys, so keep yourself at distance from moving things, don't forget the earthing is most important, keep all pets etc away from the area, finally it is all at your own risk, I take no responsibility for anything going wrong, once you have carried out initial testing and are confident that the motor will run cool and happy, then after that you don't really have any problem, as long as it is doing its job, and has enought torque and power and runs as expected, and not getting too hot or starts to smoke, and don't allow any motor to stall, as it will suerly burn out in a puff of smoke!
Are you sure the reduced vibration is due to the motor ? Are all the flexible mountings still fully flexible ? All all sides of the table free of obstructions ( I have seen one vibrating hopper against a wall ).
That motor vibrates the table vertically and horizontally mainly in one direction ( at right angles to the motor's shaft ), have you changed the way the table is used use as turning it round or the direction of work across across it by 90 degree ? If you have then the effect on material may appear to be less than it was before.
That motor vibrates the table vertically and horizontally mainly in one direction ( at right angles to the motor's shaft ), have you changed the way the table is used use as turning it round or the direction of work across across it by 90 degree ? If you have then the effect on material may appear to be less than it was before.
This is not a joke, but as with most things, natural resonant frequency of the table should also match the rate or frequency of the motor viberations, in other words if the tabel was reinforced with extra supports and members, or mountings, then you are de-tunning its natural resonant frequency and therefore the motor's effort in viberating the table will be somewhat deminished, same principles apply to electronic tunning in radios and rf circuits, if the antenna is not matched to a transmitter, then you are not effectively able to transfer the power from the source to the load.
so this means exactly what the above poster has said, is the table resting against a wall, have you changed its mountings,
Mountings play quite an important part in making the table resonate at the desired frequency, your picture doesn't give me a clear view but seems like it has a steel rod poking out of a what looks like a car shock absorber, this may have a spring inside instead of the damping a shock absorber would do, so has anyone thought it looks like a shock and changed it with a new actual shock absorber instead of a tuned resonant spring mount? A shock absorber would naturally dampen vibes, so all these things you need to consider for your table to viberate efficiently.
Hence why I asked what is his table used for viberating ? and you have not answered that question as everything is relavent.
you had a break on part of the table support or a member, you may have strengthened that part far too much, that part may have been purposely intended to flex in order to allow the table to viberate more efficiently! so there you go. Tune your table like you would your piano!
so this means exactly what the above poster has said, is the table resting against a wall, have you changed its mountings,
Mountings play quite an important part in making the table resonate at the desired frequency, your picture doesn't give me a clear view but seems like it has a steel rod poking out of a what looks like a car shock absorber, this may have a spring inside instead of the damping a shock absorber would do, so has anyone thought it looks like a shock and changed it with a new actual shock absorber instead of a tuned resonant spring mount? A shock absorber would naturally dampen vibes, so all these things you need to consider for your table to viberate efficiently.
Hence why I asked what is his table used for viberating ? and you have not answered that question as everything is relavent.
you had a break on part of the table support or a member, you may have strengthened that part far too much, that part may have been purposely intended to flex in order to allow the table to viberate more efficiently! so there you go. Tune your table like you would your piano!
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