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Three Phase Equipment?
- Thread starter m4
- Start date
Have a three phase 20" disc brinder with a phase converter.
CGT80
1/2 ton status
i just setup a 1/2hp baldor bench grinder that is 3 phase. The grinder was free and I paid $120 for a drive to convert 120v single phase to 3 phase power. It runs great. That grinder retail for about $500
I've got a Wilton 1 hp, 3 phase drill press and a Roto Phase converter.
Gus
Gus
Please explain this more, i can get a 1 hp motor 1725rpm thats brand new at work that was already paid for but nobody wants it cuz its 220-230/460. I could get this converter to run it on 120?
You can use a VFD or a RPC with 240v and get 240V three phase. I don't know about 120V to 240V three phase.
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CGT80
1/2 ton status
http://www.factorymation.com/s.nl/it.A/id.193/.f
208 three phase is just 3 legs of 120v. I think the vfd just changes the timing of the alternating current of the incoming leg to create the other two legs, I might be wrong though. At my company shop, each leg of the three phase is 120v to neutral, on some of the properties I work on the transformers provide a 277 leg. Anyway, I stuck an 1/8 piece of steel plate into the 36 grit wheel on the grinder and couldn't slow it down. It is a 1/2hp 7" bench grinder.
The vfd is supposed to provide almost 100% of the same power rating as true 3 phase, from what I read. A rotary converter is supposed to be less efficient. The vfd also controls start up and shut down speed, as well as running speed and forward/reverse start/stop. With the vfd you can not put switches, fuses, etc. between the vfd and the motor. You basically end up with a computer controlled motor.
I am very happy with my setup. I chose 120v since my motor is small, and I can move it to any place with a standard receptacle.
I am not going to get into depth here, but basically you can run a 240 three phase off of 120 up to about 2 hp with a VFD.
The VFD takes the input voltage and frequency, coverts it to DC, and then generates whatever phase, voltage, and current you want.
If you tell it to generate 3 phase 60 cycle, the motor will run at normal speed.
If you tell it 30 cycle, it will run at half speed, etc.
I may be wrong on the 120 at that horsepower. It may take 220 at single phase to go to 2 hp.
I'll find the link to the place I bought my VFD to run my big lathe and post it here in a minute.
The VFD takes the input voltage and frequency, coverts it to DC, and then generates whatever phase, voltage, and current you want.
If you tell it to generate 3 phase 60 cycle, the motor will run at normal speed.
If you tell it 30 cycle, it will run at half speed, etc.
I may be wrong on the 120 at that horsepower. It may take 220 at single phase to go to 2 hp.
I'll find the link to the place I bought my VFD to run my big lathe and post it here in a minute.
Here is the link.
Looks like 1.5 hp for 115 volts, and 3 hp for 240 single phase.
http://dealerselectric.com/variable_frequency_drives.asp
Looks like 1.5 hp for 115 volts, and 3 hp for 240 single phase.
http://dealerselectric.com/variable_frequency_drives.asp
CGT80
1/2 ton status
Do you want to run the grinder off the rotary phase converter or a VFD? The vfd takes place of a rotary phase converter.
I ran a piece of flex conduit from my grinder to a pull box enclosure that houses my vfd. The conduit had 3 hots from the vfd, a ground and two conductors for low voltage from the vfd to the on/off switch on the front of the grinder. The enclosure keeps the dust out of the vfd, as they are said to be sensitive. I have SO cord with a 15a 120v plug connected to the box to provide the input power. I can move the grinder and pull box anywhere and plug it in just as you would a 120v grinder.
If you want to run the grinder of your existing RPC, that is another story. It could likely be done but I don't remember all of the details. I would also NOT use a 120v plug with a 3 phase circuit. If someone plugged a 120v tool into the cord it would be bad. I would hard wire it. You could use and extension cord with the ends cut off, as your wire. I think most are rated at 600v, and my vfd should only be putting out just over 100v on each leg. I think my grinder only pulls 0.8 amps at 208v, according to the nameplate.
I ran a piece of flex conduit from my grinder to a pull box enclosure that houses my vfd. The conduit had 3 hots from the vfd, a ground and two conductors for low voltage from the vfd to the on/off switch on the front of the grinder. The enclosure keeps the dust out of the vfd, as they are said to be sensitive. I have SO cord with a 15a 120v plug connected to the box to provide the input power. I can move the grinder and pull box anywhere and plug it in just as you would a 120v grinder.
If you want to run the grinder of your existing RPC, that is another story. It could likely be done but I don't remember all of the details. I would also NOT use a 120v plug with a 3 phase circuit. If someone plugged a 120v tool into the cord it would be bad. I would hard wire it. You could use and extension cord with the ends cut off, as your wire. I think most are rated at 600v, and my vfd should only be putting out just over 100v on each leg. I think my grinder only pulls 0.8 amps at 208v, according to the nameplate.
I looked at a You Tube video of a vfd install, they used a 120v cord from a receptacle into the enclosure/vfd. A 1 hp vfd will run me $140 and I've already tested the grinder on my rpc in the shop.
A vfd will be an easier install but more expensive.
http://www.youtube.com/watch?v=SOxNjsuUrZA
A vfd will be an easier install but more expensive.
http://www.youtube.com/watch?v=SOxNjsuUrZA
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