I know this info has been posted on other threads, but I thought i might get some info for my lathe. I feel as though the rotary phase converter is not the best way to run this machine as it makes an awful sound when turning on the lathe. The sound does stop after a moment and the lathe does operate, but it might also be damaging either or both pieces of equipment. I have read many post describing VFD's.Hopefully someone can tell me exactly what I need to convert 220 single phase to 3 phase power. I will attempt to post the pics with this including lathe, phase converter, and lathe Hp label. Thanks for any info.
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Phase Convertor
- Thread starter hartj3
- Start date
- Replies 18
- Views 4,191
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
Converter too small for motor
a MR 1000G is a 20" lathe and likely has at least 10HP - note in later photo of tag it says 11 KW
a MR 1000G is a 20" lathe and likely has at least 10HP - note in later photo of tag it says 11 KW
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
Has over 10HP
Here is a 11KW that says it is 15 HP
Fuji Electric Motor 11 KW 15 HP 3510 RPM 3 Ph | eBay
Scroll down here and see 10 KW is 13.4 HP
How to convert kilowatts to horsepower (hp)
Fabworks
Hot Rolled
- Joined
- Jul 25, 2013
- Location
- California, USA
Info on motor plate:
220v x 36a = 7920w/ 750w per hp = 10.56hp
220v x 36a = 7920w/ 750w per hp = 10.56hp
Fabworks
Hot Rolled
- Joined
- Jul 25, 2013
- Location
- California, USA
Please forgive me as I used my "Rule of Thumb" to calculate the hp of the motor.
Let me recalculate the hp using the correct number for watts per hp: 745.699872w
220volts x 36amp = 7920w divided by 745.699872w/hp = 10.620895 hp.
Someone might buy an undersized VFD or RPC based on my understating the motor hp by .060895 hp.
Happy New Years to everyone. The PM community is awesome!
abarnsley
Titanium
- Joined
- Mar 24, 2005
- Location
- Palmer, Alaska
Pricy YES, 220 volt single phase input VFD's up to 50 hp...
On shelf, stock items.
AC Drives - Polyspede PC1-150 perfect fit...
No derate, no fuss. Fancy motor protection, instead of dumb heater units
From looks of that lathe..It's old enough to get a new single phase coolant pump. Ditch rats nest of oily electrics (contactors, heaters, control x former), and rewire for low voltage VFD controls, using original switches..
Nice being able to tweak spindle speed on the fly, to get through a vibration/chatter area on a shaft, or just to get better surface finish..
Nice lathe btw
On shelf, stock items.
AC Drives - Polyspede PC1-150 perfect fit...
No derate, no fuss. Fancy motor protection, instead of dumb heater units
From looks of that lathe..It's old enough to get a new single phase coolant pump. Ditch rats nest of oily electrics (contactors, heaters, control x former), and rewire for low voltage VFD controls, using original switches..
Nice being able to tweak spindle speed on the fly, to get through a vibration/chatter area on a shaft, or just to get better surface finish..
Nice lathe btw
Philabuster
Diamond
- Joined
- Jul 12, 2006
- Location
- Tempe, AZ
You need a much bigger RPC or a much smaller lathe.
That Mori is one sweet lathe. Let me know if you want to trade it for something smaller to work with your existing RPC.
jim rozen
Diamond
- Joined
- Feb 26, 2004
- Location
- peekskill, NY
"220v x 36a = 7920w/ 750w per hp = 10.56hp "
It's a three phase motor. Multiply by 1.7 please....
It's a three phase motor. Multiply by 1.7 please....
Fabworks
Hot Rolled
- Joined
- Jul 25, 2013
- Location
- California, USA
Oops. I did not do my 3 phase homework last night.
220v x 36a x 1.73 = 13701.6w
13701.6w / 746w per hp = 18.36 hp
A 7.5 hp RPC is definitely not enough.
I appreciate all the info. Sounds like I need either a larger rpc or try the vfc. Not sure how hard it is to convert to the polyspede 1-150 but sounds like it would be nice to operate with. Considering not the cost, it sounds like a larger rpc would be easiest, but would consider the vfd if I knew how complicated it was wiring correctly. I understand how to wire electricity as I do my own, yet getting into the electronic parts may be something harder to understand, even though I'm sure someone here can walk me through it. Don't mind spending the money, just wanna go the right direction. Already have a smaller Jet GB1340, that's why I bought this. Bought it from the owner right out of his machine shop, still wired up, in service, and made sure he sold ALL the tooling and attachments.
chuckey
Stainless
- Joined
- Jul 21, 2005
- Location
- Wensleydale, UK
I seemed to have missed a point, the RPC is switched and after some time (30 seconds+) the lathe is then switched on? Switching on the RPC which is wired to the lathe would definitely make it sweat.
Frank
Frank
Ok, after some research, I decided to shop for a rotary phase converter vs a VFD. I now realize that the one I am using is definitely too small. Not an expert on this, it seems the most practical to find a larger one. American Rotary Phase Converter Co, along with other companies, offer a 30 hp (3X the lathe motor hp) for around $2000, and seem to have a reliable product. The VFD's for this price are around $5000. With the RPC, I can continue to use all the feeds and speeds that I am familiar with, easy to install,cheaper, etc. Will wait another month before purchasing, so am still open to suggestions. If you recommend I choose a different option, please tell me the product, model number, price, and maybe the website found on. I appreciate all the comments that you guys have helped with.
It took a while to finish this, but if anyone is interested, this is the system I chose to run all my equipment. I can run a Bridgeport mill, a 15hp lathe, and a vertical 20" bandsaw without any problems. The motor is reasonably quiet, and the whole system was around $3000.
Attachments
Shawn Ghormley
Stainless
- Joined
- Jun 29, 2007
- Location
- Amarillo, TX
Who made/makes the converter?
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