DIY Home Improvement Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1 (Edited)
Hi Guys.
Hoping for you help here, story is:
I bough a industial machine (a lathe) from China, now this machine has a 380v motor but running at 50hz , 950rpm, single phase 2.2kw.

Does anyone know how to get this working? I'm looking for a 380v 60hz 950rpm motor now but i'm guessing i'd need a step up transformer from the 110v > 380v . correct?

or can i put in a 220v motor, as they seem more available than the 380's?

any help apprechiated.

Regards
J. O.

-
 

·
Super Moderator
Joined
·
20,963 Posts
Are there any other components on the lathe that use the 380 volts if not then look for a 3 HP 240 volt 60 Hz motor and then you won't need to do any converting. Are you in North America? We use 60 hz here.
 

·
Banned
Joined
·
2,487 Posts
Jack, General Hammond would want you to send it back and buy an American made machine. or at least a machine made in an English speaking country...

But the only way to get this thing to work is either a transformer, or new motor. Is it single phase or 3-phase? A new motor is probably cheaper than a transformer.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Got those hz round the wrong way, sorry yes i'm in the US, machines original motor is 50hz.

a SG-1 fan Inphase277? I've heard all the jokes about my name! :)
its single phase.

Then do you guys know where i can get a similar motor but at 60hz?
I'd still need a step-up xformer though if i did get a 220/240v motor (from the 110v standard power supply)?

J.O.
 

·
Registered
Joined
·
4,470 Posts
You can easily correct this issue with an inexpensive VFD. Your motor is 3 Hp. You will need to buy a 460 volt 3 HP VFD. Then you can set the max output voltage parameter to 380 volts and also set it to match speed (950 Max) and Hz (50) too.
You will get an extra advantage with a VFD as you can adjust the speed. You can set your pulley arrangement to the fastest setting, then use your VFD control knob to increase or decrease speed, provided you have enough torque. You can play with the pulley arrangement until you find the best one.

The VFD is only for the motor. The controls may need a transformer.

Check www.automationdirect.com (best price)
www.baldor.com (good price/ easiest to program)
www.tecowestinghouse.com (great price)
www.wegelectric.com (great price)

Search for Variable Frequency Drives (VFD). Will cost approximately $500.00 + or - a few bucks.
 

·
Registered
Joined
·
4,470 Posts
Thats why the VFD would solve his problems. I am looking at a 3Hp motor in a Weg Electric motor catalog and they offer 900 RPM. But you are right. They are not common. Motors are not rated in absolute speed due to slip. Standard speeds and poles listed are below.

3600 RPM = 2 pole
1800 RPM = 4 pole
1200 RPM = 6 pole
900 RPM = 8 pole

So a 1750 or a 1725, RPM motor would still be a 4 pole motor. Or nominal 1800. 950 RPM will be a 8 pole motor. So the OP would use a 900 RPM, 8 pole motor to replace the motor he has. Unless the motor is proprietary and was built special for the lathe manufacturer. Even special motors rarely deviate on number of poles.
Professional motor people never use the words 1750 RPM. They use 1800 to eliminate confusion.
 

·
Registered
Joined
·
13 Posts
You can easily correct this issue with an inexpensive VFD. Your motor is 3 Hp. You will need to buy a 460 volt 3 HP VFD. Then you can set the max output voltage parameter to 380 volts and also set it to match speed (950 Max) and Hz (50) too.
You will get an extra advantage with a VFD as you can adjust the speed. You can set your pulley arrangement to the fastest setting, then use your VFD control knob to increase or decrease speed, provided you have enough torque. You can play with the pulley arrangement until you find the best one.

The VFD is only for the motor. The controls may need a transformer.

Check www.automationdirect.com (best price)
www.baldor.com (good price/ easiest to program)
www.tecowestinghouse.com (great price)
www.wegelectric.com (great price)

Search for Variable Frequency Drives (VFD). Will cost approximately $500.00 + or - a few bucks.
yes an inverter will drive your 3PH motor using single phase supply. I have a Chinese lathe. Rapids coolant and main motor are 380 V, 3 phase. Light 32v. Controls are low volts, not sure what though without looking. In mine reverse changes clutches in the head electrically BUT a different speed range happens with reversing the main motor which also changes the clutches in the headstock. If your control levers are electric you should either get advice or send it back as you will run into further trouble unless you install 3 phase supply
 

·
Idiot Emeritus
Joined
·
1,910 Posts
In the original post, the motor is single phase. As you know, a VFD will not operate a single phase motor.

If it were me, I's use a transformer to boost the voltage. It'd need to be 240 volt primary, and 120 volt secondary. 0.75 KVA would be the minimum, I'd use a 1 KVA. Simply hook it up as an autotransformer, and boost the 240 up to 360. That would be close enough to 380.

This way would be considerably less expensive than a 240 to 380 volt transformer.

The original motor is 50 HZ. If this motor is operated on 60 HZ, it'll produce about the same HP, but run a bit faster. Since this motor runs at 950 RPM on 50 HZ, it is a 6 pole model. It'll run at about 1150 RPM on 60 HZ.

Rob

P.S. The motors on this type of equipment are usually metric frames. Very hard to find replacements. Sometimes, a standard NEMA frame motor can be made to fit, usually mounting holes will need to be drilled, and the belt pulley will need to be replaced as well. If it's direct-drive, it's extremely difficult to adapt to a NEMA frame.
 

·
Registered
Joined
·
13 Posts
In the original post, the motor is single phase. As you know, a VFD will not operate a single phase motor.

If it were me, I's use a transformer to boost the voltage. It'd need to be 240 volt primary, and 120 volt secondary. 0.75 KVA would be the minimum, I'd use a 1 KVA. Simply hook it up as an autotransformer, and boost the 240 up to 360. That would be close enough to 380.

This way would be considerably less expensive than a 240 to 380 volt transformer.

The original motor is 50 HZ. If this motor is operated on 60 HZ, it'll produce about the same HP, but run a bit faster. Since this motor runs at 950 RPM on 50 HZ, it is a 6 pole model. It'll run at about 1150 RPM on 60 HZ.

Rob

P.S. The motors on this type of equipment are usually metric frames. Very hard to find replacements. Sometimes, a standard NEMA frame motor can be made to fit, usually mounting holes will need to be drilled, and the belt pulley will need to be replaced as well. If it's direct-drive, it's extremely difficult to adapt to a NEMA frame.
OOps I didn't read it was single phase. Yes mine is metric frame. Just had a look at the electrical diagram. The forward / reverse clutches are 50volt All motors are 380volt 3 phase . Can't find voltage for control switches. Light is 32volt I dont know whether his has similar switching, but if the spindle control is electrical rather than mechanical most probably similar to mine
 

·
Registered
Joined
·
4,470 Posts
In the original post, the motor is single phase. As you know, a VFD will not operate a single phase motor.

If it were me, I's use a transformer to boost the voltage. It'd need to be 240 volt primary, and 120 volt secondary. 0.75 KVA would be the minimum, I'd use a 1 KVA. Simply hook it up as an autotransformer, and boost the 240 up to 360. That would be close enough to 380.

This way would be considerably less expensive than a 240 to 380 volt transformer.

The original motor is 50 HZ. If this motor is operated on 60 HZ, it'll produce about the same HP, but run a bit faster. Since this motor runs at 950 RPM on 50 HZ, it is a 6 pole model. It'll run at about 1150 RPM on 60 HZ.

Rob, I did not notice the single phase either. Just 380 volt. Never seen or heard of a single phase 380 volt motor, or a 460 volt single phase motor. ......John :huh:

Rob

P.S. The motors on this type of equipment are usually metric frames. Very hard to find replacements. Sometimes, a standard NEMA frame motor can be made to fit, usually mounting holes will need to be drilled, and the belt pulley will need to be replaced as well. If it's direct-drive, it's extremely difficult to adapt to a NEMA frame.
Rob, I did not notice the single phase either. Just 380 volt. Never seen or heard of a single phase 380 volt motor, or a 460 volt single phase motor. ......John :huh:

True metric frames are widely available in the US today. Weg Electric and Lafert USA, are two of many more that stock in the US. My local motor shop has over $300.000 of metric motors on the shelf. We have alot of foreign machinery and facilities around this area. SC.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #13
Thanks very much guys.

Now, i looked into this and its a 3 ph. motor 380v 50hz ok.

Our line is a single phase, was thinking and please chime in if im work and i probably will be :

1. get a phase converter, single ph > 3ph (115v ea line? 240v?)
http://www.phaseconverter.com/#Rotary TEMRS6000-3KW
2. transformers on each of the outputs from the phase converter to up it to 380v
3. connect a vfd from the transformers to change the hz to 60.

(long winded or what!)

from their online manuals of the vfd (460V Class - Three Phase) i noticed you cant change the voltage?
i.e input 115 / 240 > 380


I'm probably way off.

Thanks again
J. O.
 

·
Registered
Joined
·
4,470 Posts
VFD's will accept a single phase input and output three phase. At 3Hp, no derating required. Now, you can rock and roll. Much cheaper than a phase converter and no moving parts.
 

·
Registered
Joined
·
13 Posts
VFD's will accept a single phase input and output three phase. At 3Hp, no derating required. Now, you can rock and roll. Much cheaper than a phase converter and no moving parts.


But won't he need a VFD for each motor? assuming he has rapids and coolant.and what about clutches and lighting?:jester:
 

·
Registered
Joined
·
4,470 Posts
But won't he need a VFD for each motor? assuming he has rapids and coolant.and what about clutches and lighting?:jester:
Yes. Lathes that I am familiar with use a main motor for driving the lathe itself. If other motors are on this machine then he must change or rewire them to suit the voltage and hertz. Unless this is an automated lathe, there should be no cooling fluids. One motor and several pulleys to adjust speed.
Good question.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #18
its quite a straight forwad machine just the motor i'm having an issue with

but i'd still need a transformer to up the power to 380v from the vfd as power in and power out of a vfd have to be the same?

-- power into vfd (single phase) to
-- output to 3 phase 50hz to
-- step up transformers to
-- the 3 ph. motor 380v 50hz

something like this:
http://www.variablefrequencydrives.n...90010TDN4Z.htm

i think im almost there.

thanks
 

·
Idiot Emeritus
Joined
·
1,910 Posts
A transformer will be needed to use a VFD with a 380 volt motor powered from a single phase 240 volt source. It'll need to be 3 KVA minimum, if the motor is expected to produce its rated HP continuously (not likely on a lathe), then a 5 KVA will be best. It'll need to be 240 volts on one side, 480 on the other. The 480 side might be listed as the primary, and the 240 as the secondary. A transformer like this doesn't care which way the power flows. Usually, they're used as step-down, but they work just fine as step-up. It'll be much less expensive to step up the 240 single phase and use a 480 volt VFD than to use a 240 volt VFD and step up the 3 phase to the motor.

Most VFDs can be programmed for a 50 or 60 HZ motor. The actual voltage supplied to the motor will depend entirely on speed and load. For example, if the motor is running at 50 HZ, and turning just the spindle, the drive will supply a voltage of about 150 or so. When a load is applied, the voltage will increase to whatever is needed to maintain the pre-set speed.

The VFD will supply power to the motor only, nothing else. What type of control is it? If it's a simple manual switch, the VFD and transformer will work fine. If it's a start-stop button and a magnetic starter, this will get a bit more complex. If there are other 380 volt devices involved, it'll get even more complex. The reason I ask is because a 480 volt transformer will be easier to get than a 380 volt one.

Rob

P.S. If the lathe needs to reverse, it's pretty easy to do with most VFDs.
 

·
Registered
Joined
·
4,470 Posts
its quite a straight forwad machine just the motor i'm having an issue with

but i'd still need a transformer to up the power to 380v from the vfd as power in and power out of a vfd have to be the same?

-- power into vfd (single phase) to
-- output to 3 phase 50hz to
-- step up transformers to
-- the 3 ph. motor 380v 50hz

something like this:
http://www.variablefrequencydrives.n...90010TDN4Z.htm

i think im almost there.

thanks
You need 460 volts input to the VFD to get 380 volts out of it. Since you have 240 volts you need a transformer as Rob has told you. Now, you have a choice, since we are now only dealing with the motor, right????

Replace the motor or install a drive and transformer.

I am going to give you a price comparison on both so you can see what you need to do. I will use Weg Electric for the demonstration. They excel in metric motors as well as Lafert USA. They have true metric frames. If you do not get a true metric frame it may not fit in the space you have. The web site you have in your post is not the official Weg Electric website. They are online distributors only. To look at the official Weg Electric web site you must go to www.wegelectric.com.

1) Weg Electric True Metric Frame Motor:
Cat Number: 00209EP3E132S
3 HP / 2.2 Kw.
RPM: 900 @ 60 Hz / 750 @ 50 Hz.
IEC Frame: 132S (Check your nameplate) Must be the same.
Voltage: 230/460 @ 60 Hz - 380/415 @ 50 Hz.
$520.00

Find this motor and print out the frame dimensions.


2) Weg Electric VFD 08 Series:
Cat Number: CFW080065TGN1A1Z
460 Volt
3 HP.
6.5 Amps.
$460.00 Does not include transformer price. This could be the deal breaker.

IMO, the motor replacement will be the cheapest way due to the transformer. But you must be sure the motor will fit in the space you have. Go to the web site and print a cad diagram of the frame dimensions. All measurements must be the same. The bolt hole pattern and shaft size will be the same if your motor is on a 132S frame. But height and total length may vary, so be sure.
 
1 - 20 of 20 Posts
Top