I had to fit a 4hp on my student as a 3hp motor had a bit of trouble starting sometimes, it needed a little help by having to give the chuck a pull, there wasn't anything wrong with the three horse motor at all as its running a compressor now, since fitting a 4hp it starts in top speed no problem. Mine draws 70 amp on start up and 17 amp running if I remember correctly.
- Thread starter Shox Dr
- Start date
3kw inverter wont be man enough even if a quality jobby, been there wasted money not even a 4.5kw.
VFD are wired and programmed for individual machines and cant be used to operate other machinery. However an inverter you can.
Tell me more about an M300 with a clutch, could approach the perfect lathe for me.
Shox to give you some idea last machine had an old British 1 1/2hp single ph motor, current 3hp 400V non dual voltage same machine as yours.
I could put a far bigger cut on with the 240V machine like face off 3/8" on power feed, 2.25kw present 3ph moans with 1/4".
No exactly what you mean with a rotary convertor, i have one as well. Cant hear yourself think with a bit of loading.
Are there any British motors nowadays.
VFD are wired and programmed for individual machines and cant be used to operate other machinery. However an inverter you can.
Tell me more about an M300 with a clutch, could approach the perfect lathe for me.
Shox to give you some idea last machine had an old British 1 1/2hp single ph motor, current 3hp 400V non dual voltage same machine as yours.
I could put a far bigger cut on with the 240V machine like face off 3/8" on power feed, 2.25kw present 3ph moans with 1/4".
No exactly what you mean with a rotary convertor, i have one as well. Cant hear yourself think with a bit of loading.
Are there any British motors nowadays.
Eil thats exactly why a low power inverter wont work, i had to have a 7.5kw to run a 2.25kw motor.
Even then no way will it start on a useable speed from cold. Even set on 800rpm have to give it a push start with a small chuck, 2500rpm guarantees RCCD to trip out.
Even then no way will it start on a useable speed from cold. Even set on 800rpm have to give it a push start with a small chuck, 2500rpm guarantees RCCD to trip out.
Should have realised with 70A, my old 1 1/2hp blew 13A fuses 1 in 3 startups.
Motors can draw in excess of 11 times rated power on startup. Efficient ones tend to be 2 1/2 times rated power.
By some remote chance if it starts without tripping mine will take at least 9 secs to reach 2500rpm from stationary, not that i need it. Point is an inverter can only handle around 150% for so many seconds.
Then theres the point of an underpowered inverter or rotary convertor double motor power and not being man enough when a slight load is asked for. ie same machine i couldnt put 1/16" cut on without spindle stalling or slowing down with the 4.5kw inverter.
OP flog that rotary and put it towards a similar rated inverter. Luckilly yours is dual voltage so cheaper. Coolant pump is dual voltage as well.
Motors can draw in excess of 11 times rated power on startup. Efficient ones tend to be 2 1/2 times rated power.
By some remote chance if it starts without tripping mine will take at least 9 secs to reach 2500rpm from stationary, not that i need it. Point is an inverter can only handle around 150% for so many seconds.
Then theres the point of an underpowered inverter or rotary convertor double motor power and not being man enough when a slight load is asked for. ie same machine i couldnt put 1/16" cut on without spindle stalling or slowing down with the 4.5kw inverter.
OP flog that rotary and put it towards a similar rated inverter. Luckilly yours is dual voltage so cheaper. Coolant pump is dual voltage as well.
CompoSimmonite
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I replaced the motor on my old 3 phase compressor with a single phase Chinese made item. Worked great - for a while then typical Chinese build quality came to the surface and bascially scrap so not worth repairing .Total waste of money so now I have another 3 phase compressor to somehow run off my domestic single phase supply the one thing I definaltey won't do is buy a Chinese motor again.
paul H
paul H
brightspark
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try and get a brooks or crompton parkinson or a bth second hand motor. the older ones are larger and definately sustain more power than the new ones
graffian
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Have you looked on ebay?
I got a pair of moeller 3hp vfd's for 11 quid! and a few weeks after
that got a 4kw one for £20, again it was a proper make.
I thought there must be something wrong with them, that everyone
else could see and I was missing, but they work great. I alse bought
a 5 quid 3ph input 3hp vfd to see if they run ok on single phase, got it and in the manual it actually says run on single phase wire like so and derate.
^^ Why? http://www.youtube.com/watch?v=T4HytybloJA&feature=plcp and http://www.youtube.com/watch?v=wEOd-xg5PlM&feature=channel&list=UL both vids about the same lathe, owner swapped out the origional motor for a 5hp 3 phase fed by a 5hp VFD. Even reconfigured the lathe contactors so they still work (i'm guessing these now are connected to the VFDs remote connections?)
Pete.
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If you do end-up fitting a single phase you might be able to fix the contactors to work so you can keep the stock buttons etc. Depends on the voltage of the pull-in coils, some are low voltage, others work on the supply voltage. I stripped half the windings off mine to make them pull in on 240V instead of 415 and they have been working fine ever since.
penfold
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My lathe has a 550w motor; I run it using a 750w Control Techniques VFD. It works fine, which suggests that a 30% allowance is acceptable. Control Techniques actually say it will operate a 750w motor with 150% overload current for 60 seconds, and is designed for constant torque applications which require a high overload capability(e.g. cranes, hoists).
Shox Dr
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Had a look at the drive connected to the mill today. It's an Allen Bradley 1305 AA12A
Motor rated at 3HP. So should be able to run the M300.
Soooooooo.
Motor on lathe plate states; 230/415v
Has 6 wires A1,B1,C1 all linked A2, B2 and C2 go to the board.
How do I wire the drive to the lathe.
I thought first off I would wire it directly just to make sure it with run the motor. Once that is confirmed I want to wire it in so all the Safety interlocks work, and Forward and reverse works as it should.
I plain English please I hate wiring
Motor rated at 3HP. So should be able to run the M300.
Soooooooo.
Motor on lathe plate states; 230/415v
Has 6 wires A1,B1,C1 all linked A2, B2 and C2 go to the board.
How do I wire the drive to the lathe.
I thought first off I would wire it directly just to make sure it with run the motor. Once that is confirmed I want to wire it in so all the Safety interlocks work, and Forward and reverse works as it should.
I plain English please I hate wiring
Star (415) to delta (230) is best done with pics... http://www.drivesdirect.co.uk/how_to_choose.htm, another example here... http://www.electricneutron.com/electric-motor/terminal-connection-for-induction-motor/
The drive needs to be wired directly to the motor, beyond that it's all witchcraft... AIUI to get the lathe controls working they'd need to be reconfigured so that they 'feed' the remote inputs on the VFD? The more common route being to ignore the lathe controls and add a remote (start/stop, forward/reverse and speed pot) for example... http://stores.ebay.co.uk/drivesdirectinvertersltd/_i.html?_fsub=14183393
Dunno what's possible, found the user manual for your VFD but i'd need to read through the entire thing (probably several times) to properly understand how to configure things.
Yeah, true it only showed that a 5hp VFD had no problems starting a 5hp motor. There's a few that include a cut being made but not a 'proper' heavy roughing cut and not on anything big. Presumably this is where the 'advanced vector' (vectorless?) thing comes in as a basic inverter needs feedback to cope with much load?
The drive needs to be wired directly to the motor, beyond that it's all witchcraft... AIUI to get the lathe controls working they'd need to be reconfigured so that they 'feed' the remote inputs on the VFD? The more common route being to ignore the lathe controls and add a remote (start/stop, forward/reverse and speed pot) for example... http://stores.ebay.co.uk/drivesdirectinvertersltd/_i.html?_fsub=14183393
Dunno what's possible, found the user manual for your VFD but i'd need to read through the entire thing (probably several times) to properly understand how to configure things.
Yeah, true it only showed that a 5hp VFD had no problems starting a 5hp motor. There's a few that include a cut being made but not a 'proper' heavy roughing cut and not on anything big. Presumably this is where the 'advanced vector' (vectorless?) thing comes in as a basic inverter needs feedback to cope with much load?
Shox Dr
Chief Engineer to Carlos Fandango
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Cheers Pete. I found this one, that not only describes it better but also it's for a M300.
First problem I have is the wires in the motor are lose and only have tags A1,B1,C1,A2,B2,C2 so I don't understand how they relate to U,V,W
Oh, and Im not interested in farting about with variable speed on the lathe, it has enough speeds from 40-2400 for my needs including threading
First problem I have is the wires in the motor are lose and only have tags A1,B1,C1,A2,B2,C2 so I don't understand how they relate to U,V,W
Oh, and Im not interested in farting about with variable speed on the lathe, it has enough speeds from 40-2400 for my needs including threading
penfold
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For delta:
A1 joins to C2
B1 joins to A2
C1 joins to B2
A1, B1, C1 are analagous with L1, L2, L3 which is what inverter outputs are sometimes labelled as.
When I've converted motors from 440v to 240v I found it useful to use one of these for ease of connection.
Not huge as you will imagine with only 3/4hp to play with; 1mm is about the biggest I bother with unless it's very hard material. That does slow the spindle but it's a good quality motor and seems to cope well. The lathe is a Viceroy, it's the original motor.
A1 joins to C2
B1 joins to A2
C1 joins to B2
A1, B1, C1 are analagous with L1, L2, L3 which is what inverter outputs are sometimes labelled as.
When I've converted motors from 440v to 240v I found it useful to use one of these for ease of connection.
Not huge as you will imagine with only 3/4hp to play with; 1mm is about the biggest I bother with unless it's very hard material. That does slow the spindle but it's a good quality motor and seems to cope well. The lathe is a Viceroy, it's the original motor.
