Motor phase converter assistance

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Nov 7, 2012
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Need some guidance and expertise please

This surface grinder is USA made, however I'm in France. Thus it has some wiring change to 380v 3-phase to make it run for whoever owned it here in France.

My shop voltage in France is 230 V, 50 Hz.

The GE motor is 220/380 3 phase. I'll need to get some phase converter or vfd. But I need to get the right one

So I understand that the motor can be wired for 220 or 380 depending on the number of wires and the placement on the motor.

So I can bypass all the additional power boxes mounted on this machine and simply use the motor wiring direct to the phase converter/vfd. This I know how to do and have done it before

My question is- how do I know what this motor is wired for now? There are 4 wires coming out of the motor.

Wiring circled in red is coming out of the GE motor

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Screwdriver pointing at the wiring coming out of the GE motor


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Wiring coming out of the electronics box that was used to plug the machine in for power by the previous owner. This is 380v 3 phase

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It seems a bit awkward to access the motor to determine how it's wired, so that's why I'm asking if it can be determined from the information given


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You have to go to motor, open lid where wires go inside, you will find 6 terminals, 3 of them will bee bridged with metal strips, three are your outgoing wire + ground wire, which is grounded somewhere near. You have to bridge 6 terminals to three pairs, with the same metal strips, just vertical.
To better understand, read about delta and star connections, look pictures online. Maybe take pictures and ask before trying, to be safe.

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lynx85 said:
You have to go to motor, open lid where wires go inside, you will find 6 terminals, 3 of them will bee bridged with metal strips, three are your outgoing wire + ground wire, which is grounded somewhere near. You have to bridge 6 terminals to three pairs, with the same metal strips, just vertical.
To better understand, read about delta and star connections, look pictures online. Maybe take pictures and ask before trying, to be safe.

Loading…

circuitglobe.com
Click to expand...
thanks, I understand this and know how to do what you suggest
I was trying to avoid having to do this....I'm asking if there is another way to determine
 
I think that no, you really need that conversion from star to delta. Motor shield data shows 220/380, so you already have 6 terminals, you just need to access them and to wire accordingly your needs. I have converted 380 motors, who came only 380 from factory, for that you need to open motor end where 3 wires come out, find another 3, weld extensions (insulate welding, close motor), mark which one from first pair of 3 is connected to whom in second pair, then shift second three by one phase (wire), and only then you can use 220. So, you already avoided all that.
 
lynx85 said:
I think that no, you really need that conversion from star to delta. Motor shield data shows 220/380, so you already have 6 terminals, you just need to access them and to wire accordingly your needs. I have converted 380 motors, who came only 380 from factory, for that you need to open motor end where 3 wires come out, find another 3, weld extensions (insulate welding, close motor), mark which one from first pair of 3 is connected to whom in second pair, then shift second three by one phase (wire), and only then you can use 220. So, you already avoided all that.
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in thinking about this some more....as there is some sort of electronics control box with switches etc mounted on the machine, the machine is expecting 380v 3 phase INPUT.

therefore could I not just get a phase converter/VF that is - 230V single phase power INPUT from my shop -> 380V 3 phase power OUTPUT to existing 5 wires?
 
I am not sure that kind of converters exist, isn't it 230V 1Ph to 230V 3Ph only? I mean, is it really physically possible to get from 1ph 230V to 3ph 380? Isn't some 315V the absolute limit for converter inside magic from one phase 230v?
 
Well, I stand corrected. Make sure amperage is enough, (vfd output and shop wiring). Allow me just one last question - vfd and soft start - how can you implement that with factory control box? Actually, how will you control vfd at all?
 
lynx85 said:
Well, I stand corrected. Make sure amperage is enough, (vfd output and shop wiring). Allow me just one last question - vfd and soft start - how can you implement that with factory control box? Actually, how will you control vfd at all?
Click to expand...
Sorry I don't know what soft start means?

I simple wired the 380 motor on my mill into the vfd and then I plug the vfd into the outlet when I want to use it. The vfd has a start/stop button


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I have one vfd on all my tools - grinder, drill press, 40cm wide wood planer, bandsaw. I made extension cord from vfd with plug in socket and plug in whatever tool I intend to use. Soft start is how long does it take to reach full Hz, is it standard 50Hz or something I changed with knob on vfd, doesn't matter. My wood planer is heaviest tool to start, so I adjusted to start in 8 seconds, and stop in 10. During that 10 stopping seconds my vfd works as a magnetic brake. To make my life easier, I just roll with these settings everywhere. When you push start button on your vfd, it isn't instant zero to max frequency. You can see how numbers change in display, right? That is called soft start, because it doesn't hit electric grid with current spike, like happens when you plug any motor in outlet without vfd. 3 phase 380V motors with nominal working amperage of 5 amps can draw up to 30-35 amps current when starting. Vfd prevents that.
With your mill vfd is connected to motor, and you control motor with vfd, right? In surface grinder you want to connect control box to vfd and control motor from control box? Basically, you want to use vfd as a 380V outlet in your shop? If that is the case, you need to read vfd manual, does it support that. I know mine doesn't. Actually, mines instruction says to avoid any contact loss between vfd and motor, when in use. That can send current spike back to vfd and damage it. In your surface grinder your control box does exactly that - severe motor from vfd when motor is working every time when you hit stop button. If your vfd can handle that, well, then maybe it can work. I doubt it, so better get another opinion.
 
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