Need Help!- Confused about phases....

[MaNo]

All those different terms for electrical wiring makes me wonder if I ordered the wrong setup.


The local power company told me that in my area the power supply is 3-wire, single phase but I believe either I or factory made a mistake when placing order...

What I got seems to be a 3-phase setup but which would I might get to work just fine except my knowledge of electricity is just basic and my electrician did not speak with enough authority on the subject for my liking.

I checked wikipedia on http://en.wikipedia.org/wiki/Three-phase_power and find among other info .......


a) Three-wire single-phase distribution is used when three-phase power is not available, and allows double the normal utilization voltage to be supplied for high-power loads.


b) Variable-frequency drives (also known as solid-state inverters) are used to provide precise speed and torque control of three-phase motors. Some models can be powered by a single-phase supply. VFDs work by converting the supply voltage to DC and then converting the DC to a suitable three-phase source for the motor.


One 'expert' told me I need something like a 'roto-phase'

As this is not just a washing machine I want to have connected I would like to know what other CNC router users have done

when faced with a situation like that.

[Al_The_Man]

Three wire single phase in Barbados is probabally the same as N.A. this is a 240v single phase supply with a centre tap giving 120-0-120, the centre tap is usually connected to the ground conductor creating a Neutral conductor, in N.A. anyway.
The label in the pic, definitely means you need 3 phase power.
A rotary phase converter (RPC) can be used, there is also static convertors available, but a bit more money.
Many VFD's can be powered from 1 phase 240, but often the cut-off is around 5hp.
Al.

[Geof]

Yes you have a three phase machine, yes you need something like a roto-phase.

Do a search for 'Rotary Phase Converter' both here pn CNCzone and in Google. You should find many threads/posts discussing how to get three phase power from single phase.

[MaNo]

Thanks, Al and Geof, for quick reply. I forgot to mention that the spindle is 5.5 Kw which might make a difference in the final setup....No?

Al. I vaguely remember reading somewhere that for CNC machines, a static converter is not recommended. However, I don't remember where I saw that and the reason for not using a static converter. Have either of you heard of that?

Norbert

[Al_The_Man]

I have used RPC's with success, I don't have first hand knowledge of Static converters.
There are some manufacturers such as WEG that make VFD's for single phase higher than 5kw, but I believe they come at a premium price.
If you have laready bought yours then RPC may be the way to go, they are quite easy to make, BTW.
There are past post here and elswhere on the subject.
Al.

[MaNo]

Yes, Al, the machine is here already. I will have to see who's fault it is because I also received a small 1.5KW at the same time and that is correctly wired for single phase.

Anyway, it looks like an other outlay of between USD 1000 and 1500, plus shipping, duties and all that....Will have to look at the vacuum pump too for total power requirements...

Norbert

[Andre' B]

Just to throw anouther idea on the table.

My rotary converter was made from a 25KW belt driven 3PH generator and a diesel engine.

It rotates and converts oil into 3PH power.

Just about any kind of oil to, currently working my way thru 100 gallons of EDM oil I got for hauling it away.

[MaNo]

Originally Posted by Andre' B Just about any kind of oil to.....

Hmmm, are you far away from a KFC or MacDonald...

Thanks, Andre' but I do not feel like tackling a project like that. I want to get going and order a converter. The problem is, there are a number of them around and I would like to make sure I get one that is CNC compatible / rated....

My neighbour, who imports industrial equipment showed me a converter and Voltage stabilizer which, together, come to about US$ 4000. That starts to get somewhat expensive as I still have to add freight, duties, taxes, brokerage and stuff like that.

Is the voltage stabilizer really necessary ?? Does anyone have an RPC without voltage stabilizer and has no problem with a CNC router? Which brand/make?

My watercooled spindle is 5.5 KW and the Vacuum pump is 4 KW. The dust collector and compressor run on single phase, so no problem there...

Norbert

[Geof]

Scroll up the page. At the top on the right you will see a Google custom search box, just above the words 'advertise with us' in the header/ Type in 'rotary phase converter' and this will search just on CNCzone. You will get dozens of posts to peruse at your pleasure.