Using inverter with 3 phase dual voltage motor

[Col]

Hi,
I'm converting a lathe which came with a dual voltage 3 phase motor to 240V using an inverter (3phase 240V)

Do I need to rewire the motor in any way please or is it just handled in the connection box?

Thx Colin

 

[flh801978]

You need to rewire the motor to delta within the connection box ( its star connected at the mo)

do you need instructions?

Ian

 

[CHJ]

Assuming you have a standard 6 terminal connection box on the motor as Ian says it's just a case of changing the links around.

But it looks as though your connection box is constructed differently. The three brown wires on the lone terminal are the star point connections as represented in the top 415volt link picture.

 

[Col]

You need to rewire the motor to delta within the connection box ( its star connected at the mo)

do you need instructions?

Ian

Ian - yes please!
There appear to be just 4 terminals:
One has 3 brown wires attached (but no input wires), the other 3 each have one input wire and one wire from within the motor.

Colin

 

[Col]

Assuming you have a standard 6 terminal connection box on the motor as Ian says it's just a case of changing the links around.View attachment 3

But it looks as though your connection box is constructed differently.

Chas - thanks - that's what's thrown me!

 

[CHJ]

Assuming you have a standard 6 terminal connection box on the motor as Ian says it's just a case of changing the links around.View attachment 3

But it looks as though your connection box is constructed differently.

Chas - thanks - that's what's thrown me!

The three brown wires on the lone terminal are the star point connections as represented in the top 415volt link picture.
They may well have idents on them to identify which end is which, if not you will need to disconnect the three linked wires and buzz them through to the red/yellow/blue terminals to find which is the opposing end then route them to the correct RYB terminal to form a delta connection.

 

[flh801978]

As Chas says really but i'll try and expand

remove the brown input wires
remove the 3 wires that are joined together and seperate the wires
there may well be indentifiers on the wires but if not
theres basically 3 coils within the motor you have to find and mark the pairs
with a meter set to continuety find which one is connected (ie the other end of the coil) to which one. mark up or make a diagram
Then you need to connect the other end of the coil which has the start at say top right to the terminal at bottom left
then the other end of bottom left start to top left
then the top left to top right.

each terminal will end up with 2 wires to each post leaving in your picture the bottom right terminal unused

then remake the input 3 wires ...one on to each terminal...thats it really

then have fun setting up the parameters on your VFD

 

[Col]

The three brown wires on the lone terminal are the star point connections as represented in the top 415volt link picture.
They may well have idents on them to identify which end is which, if not you will need to disconnect the three linked wires and buzz them through to the red/yellow/blue terminals to find which is the opposing end then route them to the correct RYB terminal to form a delta connection.

As Chas says really but i'll try and expand

remove the brown input wires
remove the 3 wires that are joined together and seperate the wires
there may well be indentifiers on the wires but if not
theres basically 3 coils within the motor you have to find and mark the pairs
with a meter set to continuety find which one is connected (ie the other end of the coil) to which one. mark up or make a diagram
Then you need to connect the other end of the coil which has the start at say top right to the terminal at bottom left
then the other end of bottom left start to top left
then the top left to top right.

each terminal will end up with 2 wires to each post leaving in your picture the bottom right terminal unused

then remake the input 3 wires ...one on to each terminal...thats it really

then have fun setting up the parameters on your VFD

thanks guys - I understand that. Just removed the wires and the internals are nicely labelled U1 V1 W1 U2 V2 W2 - so that's clear. Does the way the inputs are connected affect which way round the motor turns?

It wasn't actually that simple since one of the nuts on the terminal block had been overtightened stripping the thread of its mounting. When I turned the nut, it spun the whole connector including the connections breaking some strands of the internal wire from the eye connector (I'll have to crimp a new eye connector to fix that!). Eventually I managed to prise it out of the terminal block and then undo the nut - at least I only need three good terminals!

Colin

 

[CHJ]

........ Does the way the inputs are connected affect which way round the motor turns?
...

Yes, direction of rotation can be changed by just swaping over any two input wires.