1 phase to 3 phase power converter

[expresssigns]

i was reading and saw that these could be bought. since i know nothing about power, and i dont have 3 phase currently, and im looking into a shopbot, would it be better to get the columbo spindle and the 15hp vaccuum and in 3 phase, and then get a converter to make it work.

are there any advantages or disadvantages to doign this? does it work as though you had 3 phase?

i know in 3 phase you can get a 15hp vaccuum, and in single phase you can get only a 7.5hp vaccuum.

[richards]

William,

A phase converter *can* change 1-phase to 3-phase, but at a *great* loss of efficiency. For example, the 5-hp Colombo spindle (3-phase) is actually 10-hp single phase.

When I bought a 5-hp converter years ago to power a 2-hp motor on a vertical milling machine, everything worked fine - at the cost of running a 5-hp motor instead of a 2-hp motor. There are electronic converters available, but the ones that I've looked at have a limited duty cycle, usually 60-percent.

If your only choice is 1-phase with a converter, you might have to plan on 25-30hp 1-phase to run the 15-hp 3-phase vacuum, and 10-hp 1-phase to run the 5-hp 3-phase spindle.

I have the 1-phase problem. At my current location, I only have 1-phase power available, which severely limits the productivity on my alpha-120, which uses a Porter-Cable router. Depending on the material, I can only run at 4-8 ips at limited depth; however, even at the lower speeds, the machine is great. Running things slower has crimped production, but it still gives me plenty of opportunity to learn how to use the machine and the available software.

[ron brown]

Horsepower is Horsepower and Watts is Watts.

It will take a larger inverter to run your machine. Be sure your inverter is the right size. An electronic "VFD" - Variable Frequency Drive" is required for the spindle. Sometimes a drive needs to be "De-rated" so there is enough input watts comming in on only two lines to power the three lines to the spindle itself.

I have setup shops with both single phase and three phase power. I have run both types of equipment off both arrangeemnts of phases. I would prefer to always run real 3 Phase stuff where real 3 Phase is available. However, large rotary inverters will convert single phase to three phase. I suggest finding a good "Electrical Mechanic" to help you through this process - at least the first time.

Ron

[richards]

Perhaps my explaination was unclear. However, in the example of a 5-hp rotary inverter running a 2-hp 3-phase motor, the amps required were the amps to drive the 5-hp motor which then generated 3-phase power for the 2-hp 3-phase motor.

I agree that a rotary converter works. If I had enough 1-phase amps available in my shop, I would have a Colombo spindle, but I only have 50-amps 240V 1-phase. I can run the Alpha, the Porter-Cable and the dust collector, but if I switch on the 2-hp horizontal boring machine, or one of the table mounted Porter-Cable routers, or the edgeband machine, or the drill press, or any other piece of equipment pulling 15-20 amps, the lights start to flicker depending on the speed of the Alpha and the depth of cut being taken with the Porter-Cable. When I only run the Shopbot, the PC and the dust-collector, there is no dip in voltage measured at the power panel. Low voltage can *greatly* shorten the life of electrical equipment. (It would cost $2,500 to $3,000 to run a 200-300 amp 240V line to my shop, which doesn't make economic sense, given the fact that I'll be moving in a few months to a much bigger shop. Trying to run an Alpha-120 in a 20x22 foot shop is much more limiting than the Porter-Cable router.)

Take a look at the Colombo web site to see the amp requirements for the 5-hp spindle driven by 3-phase and the amp requirements for the 5-hp spindle driven by 1-phase.

[johnny_s]

William-
I don't know if this helps, but the problem I had was that I moved into a single phase building with a few things that required 3 phase. The move was after my purchase of the shopbot, but prior to it's reciept. I bought the single phase Columbo, that is actually 3 phase, just less HP at single phase.

The plan was to deal with the power issue once I moved in to the new building. I think the last estimate to bring in 3 phase was $8k, so I decided it better to use the router at single phase and convert other equipment from 3 phase to single if possible. This would make it that much easier for me if I moved buildings again, because the availabilty of 3phase buildings in my size requirements (small) is pretty limited.

If I was ever fortunate enough to make a living out of my garage, this single phase setup would make the transition without problems.

As for vacuum holdown. I have had very few problems trying to find solutions without a large pump. I have a Fein shop vac that I use, and have learned to leave a paper thin skin at the end of my cuts, that holds all my parts together. I just punch them out when I am done, with slight bit (or any) of touch up afte I am done - a really nice technique for acrylic, that comes with a paper backer. I use the vacuum on panels and with smaller parts that require gasketed jigs. I have held as many as 30 individually jigged pieces with the vacuum.

[cedarknight]

We have a phase convertor with our columbo that works good because we don't have 3-phase. It is the only equipment we have that is 3-phase. We would of liked to have a vaccum that was too, but when I priced the convertors or gettting 3-phase into the building to run a large vaccum, both were not price effective. I have been like others and found way around having a large vaccum. But at first, I thought we were up the creek without a paddle until I learn some more from the forum and experinced a few trials. A person has to weight the cost of putting in 3-phase against the revenue gain once it is in.