50 vs 60 hz... Couple questions concerning a forign machine

[milemaker13]

Hey Gang!
We are looking at a new machine that is coming from Europe to the US. Power requirement for this machine is stated to be 400v at 50 hz.

Here we have 480v at 60 hz. We can use a transformer to drop to 400v, but what about the frequency? Is there anyway to convert 60 hz to 50 hz? I am aware that some electronic devices (VFDs for example) do vary the frequency to accomplish different things. However I am unaware of a device that will lower the frequency of an 80 amp 3 phase branch.

We have a meeting with the mfg in a couple weeks. Hopefully they have a solution.

 

[milemaker13]

The last machine we had from Europe was set up for 50 hz, so it kept over heating the main drive motor. After contacting service, they had me change parameters in order to set it up for 60 hz.

But my boss has asked me a direct question as to weather this will be ok to run at 60 hz. Actually, he asked if there was a 'phase converter' avalible. I was just looking for some discussion on the topic of 50 hz machines running at 60 hz.

Still hoping/thinking the manufacturer will have to set the machine up properly for 60 hz.

 

[mgookin]

The last machine we had from Europe was set up for 50 hz, so it kept over heating the main drive motor. After contacting service, they had me change parameters in order to set it up for 60 hz.

But my boss has asked me a direct question as to weather this will be ok to run at 60 hz. Actually, he asked if there was a 'phase converter' avalible. I was just looking for some discussion on the topic of 50 hz machines running at 60 hz.

Still hoping/thinking the manufacturer will have to set the machine up properly for 60 hz.

http://forums.mikeholt.com/showthread.php?t=168242&highlight=50Hz

There was recently another thread too with some phase converters but I can't locate that thread.

 

[under8ed]

The last machine we had from Europe was set up for 50 hz, so it kept over heating the main drive motor. After contacting service, they had me change parameters in order to set it up for 60 hz.

That last machine you had may have just been that rare problem bird. I am in a large, foreign owned facility where hundreds of machines were designed for 50 cycle. I have yet to hear of a problem known to be related. Many of these are on the highest end of complexity, incorporating just about anything imaginable. Of course there are some induction motor speed differences, & I used to be concerned with transformers; but that may only be an issue the other way around.

 

[under8ed]

http://forums.mikeholt.com/showthread.php?t=168242&highlight=50Hz
There was recently another thread too with some phase converters but I can't locate that thread.

I read the post linked, we have not been informed of the issues mentioned. A transformer is bought & installed with new machinery and we turn it over to production. We certainly would hear about it if modifications were required to make production. Of course I'm not saying those could never occur, just that we have yet to see that problem machine with hundreds in use.

 

[Besoeker]

Hey Gang!
We are looking at a new machine that is coming from Europe to the US. Power requirement for this machine is stated to be 400v at 50 hz.

Here we have 480v at 60 hz. We can use a transformer to drop to 400v, but what about the frequency? Is there anyway to convert 60 hz to 50 hz? I am aware that some electronic devices (VFDs for example) do vary the frequency to accomplish different things. However I am unaware of a device that will lower the frequency of an 80 amp 3 phase branch.

The most likely to be affected by the frequency are induction motors. You don't say how much of the 80A is motor loading.

 

[kwired]

If the machine has resistive loads - they are not effected by a change in frequency.

If it has solid state based controllers - they typically have the incoming AC rectified to DC - and those components are not effected by a different frequency.

AC motors on a VFD - those convert the incoming AC to DC then invert it back to a controlled frequency to control motor speed - those don't really see any difference either.

You are mostly left with direct across the line connected AC motors being the items that will give unfavorable response to a change in frequency.

 

[milemaker13]

Its a german laser. So I don't imagine any motors connected to line volts. All linear ways and electronical what not.. So maybe it will be fine. I wonder what the mfg will say. Havn't heard if they've heard back yet, lol.

Thanks for the input.

 

[kwired]

Its a german laser. So I don't imagine any motors connected to line volts. All linear ways and electronical what not.. So maybe it will be fine. I wonder what the mfg will say. Havn't heard if they've heard back yet, lol.

Thanks for the input.

If there are no front end transformers - probably fine, otherwise depends on the design of the transformer I would guess. If front end of equipment is a rectifier - probably will not be much troubles.

 

[Besoeker]

If there are no front end transformers - probably fine, otherwise depends on the design of the transformer I would guess. If front end of equipment is a rectifier - probably will not be much troubles.

Don't think transformers would be a problem - the V/f ratio is the same for both sources.

 

[under8ed]

We are running a dozen or more of those throughout this facility on 400v transformers without any attention giving to the frequency difference. Most are Trumpf brand, (spelling may be off), and typically and are on a 32.5 KVA transformer.

 

[GoldDigger]

We are running a dozen or more of those throughout this facility on 400v transformers without any attention giving to the frequency difference. Most are Trumpf brand, (spelling may be off), and typically and are on a 32.5 KVA transformer.

For motors and for some relay coil applications, getting the V/F ratio right (or on the conservative side) is a key factor.
But when used as part of a power supply to equipment (resistive heating, controls, DC supplies, etc.) omitting the stepdown transformer could lead to the right V/F ratio but excessive voltage, possibly beyond the design limits of some components.

 

[Besoeker]

For motors and for some relay coil applications, getting the V/F ratio right (or on the conservative side) is a key factor.
But when used as part of a power supply to equipment (resistive heating, controls, DC supplies, etc.) omitting the stepdown transformer could lead to the right V/F ratio but excessive voltage, possibly beyond the design limits of some components.

Spot on.

 

[under8ed]

For motors and for some relay coil applications, getting the V/F ratio right (or on the conservative side) is a key factor.
But when used as part of a power supply to equipment (resistive heating, controls, DC supplies, etc.) omitting the stepdown transformer could lead to the right V/F ratio but excessive voltage, possibly beyond the design limits of some components.

Yes, but I fail to understand why my post was quoted to introduce this information.. I posted that we do match the voltage with transformers, (3 ph.400v. from most of Europe or 3 ph. 220v. from Japan), the difference of frequency has just not been an issue to date. Our facility likely has over a hundred machines built for 50 cycle power, there are lasers, large complex machining operations, and many other types of equipment.

 

[under8ed]

For motors and for some relay coil applications, getting the V/F ratio right (or on the conservative side) is a key factor.
But when used as part of a power supply to equipment (resistive heating, controls, DC supplies, etc.) omitting the stepdown transformer could lead to the right V/F ratio but excessive voltage, possibly beyond the design limits of some components.

Reading GoldDiggers post again I understand the statement is being made there may be situations where powering 400v./50cycle equipment with 480v /60 cycle may be the ideal, since the V/f ratio is close.
We have never tried this; We supply the correct voltage, and ignore a frequency change, (of course, the purchasing engineer is informed of the alternative options & costs).
With our complex equipment, I have been surprised there has never been an issue as it is usually an operation that is time & speed sensitive.
I have wondered if equipment manufacturers have not adopted a design standard of 55 cycles to accommodate worldwide use, while tagging it as what their customer would expect.