# Motors



## McClary’s Electrical (Feb 21, 2009)

Cletis said:


> Hi, new to this area and I'll tell you this, I basically know nothing of this. My boss asked me to check and see if I can start finding out some things on the following.
> 
> We have a bunch of german machines coming in over next few years. The first one will be here in 4 months. All I know for now is it's 3 phase and 50 cycles and 125 amps. I know I need some sort of phase converter (static?). Could anyone steer me in right direction or ref's to a good manufacturer with good tech service. I can get him all the nameplate info but will need alot of help with the rest. We will have at least 20 of these coming in ranging from 50 - 300 amps 3phase.
> 
> ...


 
VAriable frequency drives control the speed of the motor by varying the frequency and voltage.

Phase converters derive a third phase from a single phase source.

WHat service do you have on the building these are going in?


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## BBQ (Nov 16, 2010)

Cletis said:


> And btw what is difference between VFD's and Phase Converter's in laymans terms.
> 
> Thanks



mcclary's electrical gave a good description but I want to add many VFDs are capable of converting single phase to three phase along with being able to change the frequency and voltage.

What voltage is the equipment?

What voltage do you have?

Is there any reason this equipment will not run on 60 HZ?

Germany exports a lot of equipment to countries that use 60 hz so it would surprise me if this equipment can only run on 50 hz.


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## McClary’s Electrical (Feb 21, 2009)

BBQ said:


> mcclary's electrical gave a good description but I want to add many VFDs are capable of converting single phase to three phase along with being able to change the frequency and voltage.
> 
> What voltage is the equipment?
> 
> ...


 
I agree. I'd be willing to bet the ratings are all calculated @ 50htz, but would most likely run fine off of 60htz.


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## Cletis (Aug 20, 2010)

*FC*

I'm guessing we need one of these. I talked to the guys at Temco. They were great to deal with. http://www.hzfrequencyconverter.com/#Frequency-Conversion

I think the machinery is 380-415V 

Bldg currently has 480V 3 phase 1600 amp

They tell me it won't work on 60HZ


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## Cletis (Aug 20, 2010)

*More*

Oh, and the guys at Temco said it would be more economically feasible if we set a few machines in one area and set a 400-600 kva Frequency Converter there for multiples. Sound right?


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## McClary’s Electrical (Feb 21, 2009)

Cletis said:


> Oh, and the guys at Temco said it would be more economically feasible if we set a few machines in one area and set a 400-600 kva Frequency Converter there for multiples. Sound right?


 
ABSOLUTLEY!!

You DO NOT wanna buy a seperate phase converter for every motor.
I would get one big enough for the whole MCC and put evrything in one place if possible.


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## alpha3236 (May 30, 2010)

to McClary,
I agree but, static PC's typically do poorly with variable loads. & having a rotary that big would be a huge power draw. Local Static's may be a better option.


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## John Valdes (May 17, 2007)

I would look at the cost conversion of the motors too. Motors are cheap compared to rotary converters and drives on each motor may not be your answer.

You give all the information except the most important. What size motors and how many per machine. You may only have to address the motors as the control is likely 50-60Hz. Same with peripheral stuff. All IEC relays and coils are 50-60Hz.

If its only motors you need to address, I would run them on 60 hz until they go out. Then have replacement 60 Hz motor or motors ready to take their place.

Please report back on 50 Hz the motors. Size and how many.


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## lectricboy (Mar 11, 2009)

Cletis said:


> I'm guessing we need one of these. I talked to the guys at Temco. They were great to deal with. http://www.hzfrequencyconverter.com/#Frequency-Conversion
> 
> I think the machinery is 380-415V
> 
> ...


 I have wired 380 volt, 50 Hz motors to 480 volt, 60 Hz systems in the past, and they would run fine, an electrical engineer explained to me that as long as the ratio of voltage/ Hz increase is the same, and the motor windings are rated at 600 vac, there shouldn't be a problem.


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## BBQ (Nov 16, 2010)

lectricboy said:


> I have wired 380 volt, 50 Hz motors to 480 volt, 60 Hz systems in the past, and they would run fine, an electrical engineer explained to me that as long as the ratio of voltage/ Hz increase is the same, and the motor windings are rated at 600 vac, there shouldn't be a problem.


True ....... but the motors will also run faster ......... if this is a problem or not depends on the equipment the motors are driving.


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## lectricboy (Mar 11, 2009)

BBQ said:


> True ....... but the motors will also run faster ......... if this is a problem or not depends on the equipment the motors are driving.


Agreed, I was wiring a saw, so speed wasn't a big issue!!


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## JRaef (Mar 23, 2009)

Motors provide an amount of torque at a selected speed. To accomplish this, they use electro-magnetic flux to create torque. Flux strength is related to the ratio of voltage and frequency, as long as that ratio is maintained, the torque remains the same. So a motor designed for 380V 50Hz has a V/Hz ratio of 380:50 or 7.6:1. A motor designed for 460V 60Hz has a V/Hz ration of 460:60 or .... wait for it... 7.6:1! 

So you do NOT need a "phase converter" to use 380/50Hz motors on 480V. The motors will spin 20% faster and that may be an issue for some loads. Centrifugal pumps and fans in particular can be problematic because with thse types of loads, the power requirements vary by the cube of the speed. So if a pump runs 20% faster (120% speed), then the power required by the new speed will be 173% of what it was. So watch out for that, you may need to make sure you have a way to control flow, or use a VFD.


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## Jlarson (Jun 28, 2009)

lectricboy said:


> I have wired 380 volt, 50 Hz motors to 480 volt, 60 Hz systems in the past, and they would run fine...


Agreed, you just need to watch out so you don't screw up the process because of the increased speed.


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## McClary’s Electrical (Feb 21, 2009)

JRaef said:


> Motors provide an amount of torque at a selected speed. To accomplish this, they use electro-magnetic flux to create torque. Flux strength is related to the ratio of voltage and frequency, as long as that ratio is maintained, the torque remains the same. So a motor designed for 380V 50Hz has a V/Hz ratio of 380:50 or 7.6:1. A motor designed for 460V 60Hz has a V/Hz ration of 460:60 or .... wait for it... 7.6:1!
> 
> So you do NOT need a "phase converter" to use 380/50Hz motors on 480V. The motors will spin 20% faster and that may be an issue for some loads. Centrifugal pumps and fans in particular can be problematic because with thse types of loads, the power requirements vary by the cube of the speed. So if a pump runs 20% faster (120% speed), then the power required by the new speed will be 173% of what it was. So watch out for that, you may need to make sure you have a way to control flow, or use a VFD.


 

Good to see you here:thumbup:


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## Neilgrimsley (Dec 16, 2010)

*voltage reversal*

I have just the opposite case... I'm in Jinan China with a 380/50 power supply and am installing can lines out of a US plant rated at 480/60. I have my ideas as to what to expect, but please voice your opinions as to under voltage and frequency's effect on Drives and motors. Thanks guys


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## JRaef (Mar 23, 2009)

Neilgrimsley said:


> I have just the opposite case... I'm in Jinan China with a 380/50 power supply and am installing can lines out of a US plant rated at 480/60. I have my ideas as to what to expect, but please voice your opinions as to under voltage and frequency's effect on Drives and motors. Thanks guys


Same issue, but now they run 20% slower. No problem unless you need HP(kW) and not torque because the motors are now going to put out 20% less HP as well. it all depends on the application. Can lines, probably high speed conveyors, extruders / punches etc. I don't think you will notice, other than the slower speeds.


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