Gunsmithing Some Voltage and Frequency Lathe Questions

[Matabele]

Hi guys,

I was wondering if anyone with some electrical knowledge could give me some advice. Im looking to buy a Grizzly G0509G lathe. So the Grizzly is a 3 phase, 120 Volt machine that is designed to operate on a 60Hz Frequency power supply. I would like to import this lathe into South Africa which uses a 220-240 Volt system but runs on a 50Hz frequency. Is it possible to somehow convert or transform the power supply to get this lathe to operate ok in South Africa?

Any advice appreciated thanks!

 

[Mad_Charlie]

Ask Grizzly!

I believe there are converters, but I would definitely contact Grizzly.

 

[E. Bryant]

A variable-frequency drive (VFD) would likely be the way to go, but would require some wiring modifications. As suggested above, contact Grizzly first.

 

[Matabele]

Thanks for the replies guys, appreciate it. I have emailed Grizzly and am waiting on their reply, I was just wondering if anyone else could offer some advice in case Grizzly cant recommend anything due to warranty concerns.

 

[Cncjerry]

VFD is the way to go, hooks directly to the lathe, no wiring mods to the lathe at all. VFDs work by varying the frequency to the motor to adjust speed, at a minimum, and do other things to the wave to control braking and torque. They take 220v in and convert it to three phase out with variable frequency and some add DC for braking. The one I have on my mill does all kinds of ramped start, stop, torque, jogging, forward, reverse you name it. They are very common and cost about $200 USD per HP for a good one, I think mine is made by HP? Can't remember.

 

[Nate O.]

Hi guys,

I was wondering if anyone with some electrical knowledge could give me some advice. Im looking to buy a Grizzly G0509G lathe. So the Grizzly is a 3 phase, 120 Volt machine that is designed to operate on a 60Hz Frequency power supply. I would like to import this lathe into South Africa which uses a 220-240 Volt system but runs on a 50Hz frequency. Is it possible to somehow convert or transform the power supply to get this lathe to operate ok in South Africa?

Any advice appreciated thanks!

you'll also need to know if the grizzly is wired "WYE" or "Delta"

 

[Gene Poole]

you'll also need to know if the grizzly is wired "WYE" or "Delta"

I don't think that has anything to do with it. Both take the same 3-phase input power.

 

[Matabele]

Thanks for the replies guys, Its great to know there is a simple solution to this, relatively cheap too. The Grizzly lathes seem like good buys for the money and the company had been great to deal with so far.

 

[Pinecone]

In most of the world, power is 3-phase to the house.

You will normally need to either change the motor to a 50 Hz motor, or run a converter to convert the frequency. But this is not as simple as converting the voltage.

The easiest and cheapest way is to change the motor for long term.

 

[338RUM runner]

Looked on the Grizzly site and the Lathe is 220 Volt 3 ph not 120 Volt 3 ph. Just wanted to make sure that those who are helping have the correct info. I have the G0709 and i'm very happy with it.

Hi guys,

I was wondering if anyone with some electrical knowledge could give me some advice. Im looking to buy a Grizzly G0509G lathe. So the Grizzly is a 3 phase, 120 Volt machine that is designed to operate on a 60Hz Frequency power supply. I would like to import this lathe into South Africa which uses a 220-240 Volt system but runs on a 50Hz frequency. Is it possible to somehow convert or transform the power supply to get this lathe to operate ok in South Africa?

Any advice appreciated thanks!

 

[Matabele]

Looked on the Grizzly site and the Lathe is 220 Volt 3 ph not 120 Volt 3 ph. Just wanted to make sure that those who are helping have the correct info. I have the G0709 and i'm very happy with it.

Yep my bad, you're right 338RUM its 220 Volt, got my wires crossed (hehe!!). Out of interest what would a replacement 50 Hz motor set me back about?

 

[Pugilist]

I would wait and see what grizzly says before you move with it.

If it is 220v 3ph, the voltage will more than likely not cause you an issue but the frequency could.

Depending on the motor, it may handle the frequency difference just fine and run a little different from the calibrated speed (probably a little slower). Since it is on a big lathe, I wouldn't expect the motor to be very sensitive - so I would expect it to run without issue. But I am not confident enough that I would try it without using a converter.

Also be careful with the VFD's - while most motors will run on freq drives. It can cause issues with some after a while (esp light duty motors or motors that have a cooling fan driving off the motor shaft).

If it were me, I would look into switching the motor (simple swap) and changing the control power transformers - will be cheaper then converting the power or trying to find a suitable freq drive. Plus, it will be far more reliable/safer in the long run.

 

[Matabele]

Thanks for the reply Pugilist, hopefully Grizzly will give me some feedback tomorrow. Would you be able to give me a ball park figure for a replacement motor? It might work our cheaper to source one in the US and have it shipped out with the lathe than trying to find one locally.

 

[Cncjerry]

The lathe will run approximately 1/6 slow on 50hz as that determines the lead if you get three have dropped at your house, a very expensive option. Contrary to the statement above, most power to homes is 220v single phase. By taking either leg to ground, actually neutral, you can split the 220 into two 110 legs for balance. This will not drive a three phase lathe. Get a VFD which will convert the 50 to 60 with no issues at all. You then control the speed of the lathe with the VFD. Swapping the motor to 220 or 240 single phase is a waste of a good motor. The power factor is higher with a three phase motor. I use a VFD on my CNC mill and if I remember it is 3hp and cost $220USD.

 

[Pinecone]

Power to home in the US, is 220 volt single phase 60 Hertz. Yes, two legs, each legs is 110 volts to neutral/ground and from leg to leg, it is 24 volts

The OP is in South Africa, where, like most of the world, power to homes (and everywhere) is "220" volt 3-phase 50 Hertz. Each power lead is 220 or 230 or 240 volts phase to neutral. Phase to phase depends on which system, but can be 380, 400, 0r 415 volts. And yes, houses have 4 wires coming into them. 3 power legs and a neutral. And for fun, in many countries there is no ground.

Running a 60 Hertz motor on 50 Hertz makes it run slower, but also increases the current, which increases the heat, which decreases the life of the motor.

 

[Clark]

Running a 60 Hertz motor on 50 Hertz makes it run slower, but also increases the current, which increases the heat, which decreases the life of the motor.

The increase in current is magnetization current. This is independent of load. It is not real power as is lags the Voltage. It may may not cost any more if the power meter does not penalize for bad power factor.
The magnetization current in aircraft motors can be huge due to weight concerns, and they are still flying. When we design magnetics, a major problem is the temperature rating of the wire insulation. Magnetization current using a heavy 60Hz utility motor at 50 Hz will likely be tiny compared to when the lathe drills a 1" hole in steel. And so the magnetization current will be a minor player in ever getting the wire insulation too hot.

http://www.the-power-factor-site.com/motorcurrent.html

 

[Cncjerry]

World Power Supply Voltages - KEYENCE Corporation

So that link must be wrong. Not that I know, as I always travel with those stupid adapters that overheat my equipment, but it states that it is all single phase across the major countries with three phase as an option. Three phase takes an extra inductor and it is expensive to purchase as my in laws farm was over $250k for three miles. Maybe since they don't use neutral in some countries the can deliver it inexpensively.

He still needs and wants a phase converter the advantages are numerous over even straight three phase.

 

[Matabele]

Hey guys. Well just wanted to update this as Grizzly got back to me. As I suspected they didn't want to recommend anything that their equipment was not designed to run on...can't blame them on that, Id do the same. They also said running their equipment in a way they were not designed for would void the warranty, so basically If I order one I'm on my own.

So is a VFD still the way to go? If the worst that can happen is I burn a motor out and have to replace it, that still wont be a deal breaker.

 

[Pinecone]

I have been in electrical panels in about 120 countries so far.

And the vast majority of countries bring 3 phase power into the building, even residences. But they are typcially wired for single phase to each outlet. But providing 3 phase is simply adding a breaker and some wire and an outlet.