Dealing with a European machine & its voltage

Experts on this can chime in and correct if need be but I would probably use VFDs with line and load reactors.
VFD will easily take the 480V and output 400V if you set it to.
It will also output 400V at 50Hz if you set it to.

VFD does not care what line voltage is coming in as long as that voltage is within spec for the particular model VFD. VFD output is totally programmable and you can do quite a bit with it.

The 230 I would just transformer down because that one should be small and cheap.
 
Yes, I forgot to add that option as well, If each motor will need a VFD, it will be expensive as well. Also, I mistyped , that option#3 using transformer to 400v/60HZ , motor will actually run faster , not slower.
@timryder: Thanks for the link. I will check it out
 
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Do NOT get a transformer! Giving 400V 60Hz to a motor designed for 400V 50Hz will kill it. A motor designed for 400V 50Hz has the same V/Hz ratio as 480V 60Hz; 8:1. That's what the motor wants to see. If you transform down to 400V but at 60hz, the ratio drops to 6.67:1, about 17% less, so your motors will produce 17% less running torque and 30% less Starting / Accelerating torque. That means they will run at higher slip and pull more current and run hotter, while doing less work. They will prematurely fail.

Add to that the fact that, as others mention, the fans will demand MORE power (173%) at the higher speed, you have a situation where your motor delivers LESS power while the load demands MORE power. Failure is almost immediate.

Feed the motors with 480V 60Hz, then deal with the air flow increase either by using belt drive changes as mentioned, or if there are dampers, closing off the dampers. All you need is for the motor amp draw to be the same as the nameplate rating. However you get there is fine.

You could also just put VFDs on the 3 phase motors, problem solved, budget busted.

As to the single phase motors, you might be screwed no matter what. If the motor nameplates happen to say 230V 50/60Hz, you are golden, but again depending on the TYPE of load. If they too are centrifugal pumps or fans, the same "affinity law" applies; power required by the machine will increase by the cube of the speed change. 120% speed = 1.20 cubed = 173% power. But if you can adjust flow, you can compensate.
but one thing is for sure, you will need to get a 480-230V transformer for those motors and separate out the circuits. 480 phase to neutral is, at best, 277V here. At worst, you have a Delta system so no neutral at all, meaning it is "floating" and potentially there is 480V phase to ground.

Heaters will not care one iota.
 
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@jraef. That was my listed option#2. It will run same speed with same ratio 8:1 , but hotter with higher voltage. use it as it is with US voltage 480v/60. And I was concerning with the heaters, but you said it will be no problem?. I agreed that one leg from 480V will give 277V, and since these motors are small ones, a small transformer 480 to 230 will be need it. This 230v will be one phase , correct?
 
The 400 volt (really 388) and 50 Hz will run fine, but the loads may be mismatched when you are running a 1500 rpm motor at 1800.
The motors will not overload unless that driven load is a pump or a fan where the power required goes up exponentially with speed.
The heaters might give you a problem since they are going to be straight volts amps = power.
The motors will of course put out more horsepower, but they will run just fine with the above noted.
if you are driving fans with pulley sheaves and belts, then change the ratio.
If you are concerned about the heaters what are you controlling the heat with?
If a power controller controlling temp with SCRs or Triacs then probably still no problem.
If a direct drive fan now you have a problem. A damper MIGHT put you in the correct range, however.
The fan critical speed could be of some concern.
 
For completeness sake, there is a "sale only" company that sell transformer+ freq. converter that will convert 480V/60Hz system to 400V/50Hz. It's damn expensive and my experience with them is not very good, I would not recommend it, but here is a link:
http://www.gohz.com/150-kva-frequency-converter

In general, most Europeans machines are 400V/50Hz, then get a 380Y transformer. Do not get the 400V, you will be fine.
 

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