Converting a USA machine to France power

[Chris Elston 79]

So I have this old machine I am helping a company ship to France. So far I see that it doesn't appear I can just buy a step up transformer from 400 V / 50HZ to supply the USA equipment rated at 480 V / 60 HZ. HZ is not a problem, motors will run slower but that's ok. However voltage is a problem. It's looking to me I need to change the motors. Unless there is a product out there that will convert the power? Anyone shipped equipment that was designed to USA overseas with a 400 V / 50 HZ rating? Just wanted to hear your thoughts.

[TimWilborne 108]

This is going completely off of memory but I was doing a job in Southeast Asia and if I remember right a 480 VAC 60 hz motor will run on 380 VAC 50 hz fine but you must derate it 85%. Running short on time but I will try to find an article on it tonight.

[Steve Bailey 118]

If those 460 VAC motors were hooked up to a VFD, at 50Hz the VFD's output voltage would be 380 volts. Don't worry about the lower voltage as long as the Volts/Hz ratio is maintained. Worry more about locating a control power transformer with taps so that you can maintain your single phase power at 120 VAC. If the machine has a PLC, it may not be happy at 100 volts. Starter coils and solenoid valves will draw more current at lower voltage levels.

[P Daniil 0]

Assuming this is an AC induction motor, as long as the V/f (volts to frequency) ratio is the same, you are OK. So as 480 x 50 / 60 equals 400 there is nothing to worry about the line supply. The motor however may not be able to develop the same power (ie increase the current to develop the extra torque needed) as this depends on the motor construction, power, slip and the load. The motors we get on this part of the world usually carry rating plates with 50 and 60 Hz sets of values. Is there a rating plate still on this old machine? If so, it may be of help. As a final check and to be on the safe side, I would drive the motor with an inverter at 400V/50Hz and see how the whole setup behaves. What is the power of the motor?

[Chris Elston 79]

I didn't even think about using a VFD...great solution...thanks guys! Sometimes you forget the obvious.

[ECSI 17]

A VFD may not be much good to you in this case since the supply line to it will be 400V 50HZ. You will be able to overspeed to get 60 HZ output but you won't get more than the 400V on the output. You may see a significant drop in torque at 60 Hz and find that the motor will be undersized for the application.

[Steve Bailey 118]

I'm not even sure you'll need the VFD. I was simply pointing out that if you applied a VFD to the motor, the VFD's output at 50 Hz would be the same as the across the line conditions in France. Putting a VFD on it here will be a good test of whether or not it will work properly in France. I wonder what would happen if you used a VFD set up for 50 HZ, 380 Volt output as your three-phase supply to the entire machine...

[comeng 0]

I agree with Steve your biggest problem will probably be the control side and may I suggest you are not the person ensuring it complies with the relevant European safety legislation. Not that I am suggesting you would not be fully competent to do it but it can be a minefield Edited 19 Dec 2007 by comeng

[TConnolly 13]

I have refitted several machines, both used and new, for shippment into France and Italy. Motors were never a problem. A 480V 60hZ motor works just fine on 400/380 50hz. It turns slower however so you may need to take that into consideration. Any hydraulic systems will be slower. Motor speeds will be about 2900,1450, and 950 RPM instead of 3500, 1750, 1150 RPM. I found that it worked best to make all of the controls 220V and 24V, with a heavy preference for 24V except for large loads. You can feed the machine with four wires so you get your 220V without the use of a transformer - just be sure the branch breaker breaks both H and N. Use a 3 phase 400 x 24V power supply for your 24V - most three phase switchers have a large input voltage range so these aren't hard to come by.

[leonuce 0]

You should not have much problem if you use a VFD and set output voltage and frecuency according to you need. The only issue you may encounter is the input voltage but most VFD are design to work with +-15% of the input voltage.

[TimWilborne 108]

Derating may not be necessary depending on your application but you probably need to consult with your motor manufacturer http://www.iprocessmart.com/leeson/leeson_iec_article.htm

[JesperMP 2]

No. Recent directives specify that for anything but extremely simple controls, single phase AC control voltage MUST be derived from the mains supply via a transformer. And then do select one that allows varying input votages (they typically allow 380V - 440V) via different taps.You can keep 110 VAC control voltage if you dont want to strip out every relay or contactor in the existing controls. If there are devices that need 230 VAC, you simply add a separate transformer for that voltage. I see a number of pitfalls for sending an old machine to europe. Safety. If the machine is up-to-date with the most recent US directives, then it will be OK, but if this is an archaic machine, you must start from scratch with a risk assesment and so forth. User manuals (not service manuals) must be in the local language, and pay extra attention to the safety part. EMC directive. Parts must have the CE tick. If they do not, your best bet is to evaluate the machine as a whole unit (outside consultant ?). If there are only "normal" controls and no special electronic units, it will not be such a big deal. If there are special electronic units, you may want to exchange them for types with the CE tick.

[Chris Elston 79]

I went ahead for kicks and giggles got a custom transformer quote from HEVI-DUTY. 112 KVA transformer was quoted at $6700. 380 PRI 480 SEC 100 AMPs (112 KVA) approx. They quoted 10 day lead time custom transformer. I could probablly buy 6 VFD drives for that price, but I haven't dug into the entire controls package yet, like you guys have said, need to look at the control voltage and dc power supplies and such. Slapping the right kind of build transformer on the front end of the machine would insure it runs at the designed voltages. 50 HZ will still be in play, but it's been tested at the slower speeds already so no issue there.

[TimWilborne 108]

Are you sure 480VAC 50 hz is going to operate satisfactory? Look at the right column of the chart in the link I posted. Looks like 400VAC 50 hz would be better according to what I am reading

[TConnolly 13]

Thanks for the update Jesper. Its been acceptable in the past and we never had any problems getting the machines certified, but that was several years ago. I was glad we were able to do it that way because the machines have a 70 amp single phase 220V load in addition to the control voltage. That would be a rather large transformer. I'll keep that in mind and check out new directives because I certain that sooner or later we will do another.

[JesperMP 2]

70 A @ 220V ! ouch. Hmmmm..... If the 70 A is because you have single phase motors (pesky things !), or heating elements, then you can investigate the loads a little further. If single phase motors, then maybe they are really 3-phase with a capacitor. If that is the case, then maybe you can throw out the capacitor and connect in star with 3x400V. Or if heating elements, then they can possibly be connected in another way - for example 2 or 3 in series in stead of parallel.

[TConnolly 13]

It was a heating load. One 15KW element - the physical arrangement of the apparatus dictated the element arrangment. In practice the element is never driven at the full 15KW, but the possibility to do so was a part of the specification. But we also had some minimal 220V control (PLC power/24V Power Supply/Large contactor coils/HMI power) which also was derived from Line/Neutral, and the inspectors didn't give us any hassle about it. That was in 2001.

[JesperMP 2]

It is only the control part that must be supplied via a transformer, not the whole single phase part. And if this consists of very few contactors and other elements the requirement for a transformer disappears. I dont know exactly where the limit is. I would consider a control voltage transformer if I were you anyway. You can install a type with so many taps on the input side that the control can be adjusted for different locations (380V-400V-415V-440V are typical). This is what we do actually. The power part should be arranged so that as much load balancing is achieved, even if it is single phase L-N. If there is only one single element then there is not much you can do about it.

[TConnolly 13]

Thank you for the info Jesper. I'll keep that in mind and use a control transformer next time. As for balancing the large single phase loads, since there were several of these machines we moved the single phase load to a different leg for each machine and noted it on the drawings.