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Running 3 phase lathe via an inverter from a single pahase supply
2

Running 3 phase lathe via an inverter from a single pahase supply

Running 3 phase lathe via an inverter from a single pahase supply

(OP)
I have a Boxford CUD lathe, 3 phase.  I have bought an inverter (Kasuga KVFH-200v-0.75Kw).  I have been told I need to change over some connections in the motor to change it from star to delta. The motor connections at present are
Terminal A - Red & white cables, Terminal B - Yellow & white cables, Terminal C - Blue & white cables, Terminal N - Brown & black cables. I think the white cables are the supply cables.
The plate from the motor suggests the following connections for Delta - Terminal A - Red & Brown, Terminal B - Yellow & white, Terminal C - Blue & black, no connections to terminal N. I have digital pics of the terminals if anyone is interested.  
As you can probably tell I am not an electrician, I am just trying to get an idea of whether I this is a job I can do myself or if I should just bite the bullet and get in a qualified spark to do this for me.  All help greatly appreciated.

RE: Running 3 phase lathe via an inverter from a single pahase supply

Look at the motor nameplate voltage listing.  The single phase supply voltage, the drive output voltage, and the motor wiring configuration should all match within about 10%.

Your motor may be wound for two or even three voltages. Pick the configuration that matches the drive output voltage.

RE: Running 3 phase lathe via an inverter from a single pahase supply

Post the pictures. Make sure you include one of the nameplate if you can.
 

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  Sometimes I only open my mouth to swap feet...

RE: Running 3 phase lathe via an inverter from a single pahase supply

If this is a UK lathe - Boxford are an English manufacturer for the benefit of the furriners around here wink - AND the motor was connected in star for use on a 415V supply then yes you can use the motor with a 1ph - 3ph inverter if you reconnect it in delta. If the motor was delta connected for use on a 415V supply you have a problem. Fortunately for you most small motors are 240V delta /415V star but there are always odd ones which are 415V delta / 690V star just to add interest.
 

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  Sometimes I only open my mouth to swap feet...

RE: Running 3 phase lathe via an inverter from a single pahase supply

(OP)
The lathe originally came from a school, so I am sure it is a UK lathe & was connected to a 415V supply.  I haven't changed the wiring so it looks like it is connected in star.
It looks like the images loaded ok so I will upload the wiring diagram from inverter manual, see if it makes sense to anyone. Is the 'commercial power supply line' my single phase supply? So will terminal T be earth? Does it matter which way round L & N are connected to terminals R & S, or am I way off the mark.




Also on the motor connection images it tells me there should be black & white cables @ terminal N in star but the actual wiring of the motor there are 2 browns & a black.

So am I right in saying to re-wire the motor in delta (mesh?)  I need red & brown @ terminl A, yellow & white? @ terminal B, blue & black @ terminal C, and nothing connected to terminal N.

The lathe is actually up at my dads & i'm off up to see him this weekend so I will see if I can get any more info on the motor. I realise this is probably all basic stuff to most of you but it would be great to get this little lathe up & running.
Thanks for all your help.

RE: Running 3 phase lathe via an inverter from a single pahase supply

That inverter is designed for a 3-phase input. R-S-T are the three phases. You can usually use a single phase input connected to any of the three phase terminals, any polarity. The third terminal must not be connected. The inverter input voltage must be compatible with the supply you have: I guess this is a US-origin 208V 3-phase inverter? You can probably use it on 240V single phase without problems but check the manual.

You need to determine which brown wire is associated with which phase to ensure you connect it correctly. To be honest you should probably get some help from a competent person because there are other things such as an emergency stop which are required. No one on this board wants to see anyone get hurt as a result of well-intentioned advice which was misunderstood. Don't take that as a criticism - many of us here work in the high hazard industries and have a very safety-conscious attitude.
 

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  I don't have an attitude problem. You have a perception problem...

RE: Running 3 phase lathe via an inverter from a single pahase supply

(OP)
I think you are right, I am well out of my depth.  Thanks very much for all the advice, I can pass it onto the electrician when I finally get round to sorting this out, it's only been 6 years.

Thanks Again.

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