European Voltage Equipment used in North America

[cfordyce]

I have 400V (380V) rated production equipment in my Plant which is comming from Germany. Up til now we have special ordered step-down powee transformers to supply this equipment with it's rated 400V 3ph power. I noticed that the spec on the equipment indicated an 'PERMITTED RANGE OF VOLTAGE FLUCTUATIONS: 340V - 440V'.

Question: Would it be possible to power this equipment with a North American standard 347V or 460V secondary Transformer? With 10% tabs, I could get approx. 347+35=382V or 480-48=432V. Do you see any problems with this approach?

 

[busbar]

Having no idea of kVA requirements or frequency sensitivity of the served equipment, there is
“Economical auto connections three-phase using two single-phase (stock) transformers”
480 Volts ? High Volts – 380 Volts ? Low Volts (Open Delta)–3Ø, 50/60 Hz

http://www.jeffersonelectric.com/pdf/3-phaseencap.pdf

 

[jghrist]

Standard transformers in the US have 2±2½ taps giving a minimum of 456 volts with nominal volts on the primary of a 480 volt transformer. Utilities are permitted to have as much as 5% overvoltage, so even at -5% tap, you may have 480 volts on the secondary.

347 volts is not a US standard. There is much more variety in standard medium voltages, so you may be able to get 400 volts secondary by using a different high side voltage. For instance, if the nominal high side is 12470 volts and you used a 13800-480 volt transformer, the neutral tap low voltage would be 434 volts at nominal high side volts.

 

[alehman]

If you have a significant amount of 380V load, just buy a 380V transformer. They are available. See page 10...

http://ecatalog.squared.com/techlib/displaydocument.cfm?id=7400CT9601&action=view

 

[jbartos]

Suggestion to the original posting: More descriptive information about the project is needed. The load may be sensitive to frequency, e.g. 60Hz in America versus 50Hz in Germany.
The 432V voltage obtained from 10% tab at the transformer can fluctuate by about 5% to 10% above 432V to 453.6V to 475.2V due to the Utility power supply voltage fluctuations.

 

[wde3477]

We had a similar situation with equipment from Europe. Since the equipment was relatively new and our installation & start-up time was extremely limited, we opted to put several small 480/380 transformers in place with the thinking that as various components failed on down the road, we would then either take that particular transformer out of service and replace the failed equipment with 480V-rated equipment, or have the option to continue with the European-spec equipment to avoid any retrofit problems. The electronics had no problems between 50Hz and 60Hz. We re-pulleyed the fan motors (1.5 - 25kw) to maintain the design impeller RPM, and after two years we have not seen any significant problems running 50Hz motors on 60Hz.

 

[Handasee]

You have not specified the motor nameplate frequency?
If it is 380 volts 50Hz then that would be equivalent to a 456 volt 60Hz. So a 440 or 460 volt transformer would do the job. One problem that should be investigated on the machine is the control transformer. Check that the output voltage of the control transformer is as specified on the wiring diagrams.

 

[jbartos]

Comment on wde3477 (Electrical) Mar 22, 2004 marked ///\\We re-pulleyed the fan motors (1.5 - 25kw) to maintain the design impeller RPM, and after two years we have not seen any significant problems running 50Hz motors on 60Hz.
///This sounds good. So far so good. The motors will probably experience shorter life-cycles due to somewhat increased internal temperature due to the higher Eddy current losses and remagnetization losses (Steinmetz Law). A lot depends how the motor is actually engineered and designed. There are various constants in the motor engineering and design that can make the motor better of worse.\\\