German Table Saw 460V

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SOMDJosh

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The Carpenter where I work Just got a really fancy table saw from Germany with a name plate voltage of 460Vs, we were told to just hook it up to a 480V circuit. The saw is not operating as it should and the techs from the company said we need to supply 460Vs to the saw. I asked the supply house for a 480V Delta to 460V delta transformer and they said it needs to be custom made and its very expensive. Is there another option I can do to solve this or does someone know of a different transformer I can order?
 
I find it hard to believe that a 20 volt difference at that voltage matters. Is the saw rated for 50 Hz or 60 Hz?
 
1) What 'flavor' of 480V is your current supply? (It could be 480/277V wye, 480V ungrounded delta, etc.)

2) Did the fancy saw give an error message?

3) Does the fancy say use VFDs internally?

4) Does the fancy saw need 460V or 416V?
 
Buck/boost transformers are the easy and cheap way to reduce the voltage. Many machine manufacturers offer auto transformers to convert US voltage to European voltages. Check with the manufacturer.
 
NEMA rated motors designed for use on 480 V systems are always rated for 460 V on the motor nameplate. This is to allow for voltage drop between the source and the motor.

So if the equipment truly has a nameplate that says 460 V 60 Hz, that would be entirely appropriate, and no changes should be required to the incoming voltage.

If this motor is a direct on line motor (constant speed), I think it's unlikely that 480 V instead of 460 V is your problem.
 
They often remark 50 hz 400 volts motors at 60 hz, 460 volts as the voltage to hertz ratio is very close. However that does not account for the additional load resulting from the higher speed at 60 hz.
 
infinity said:
I find it hard to believe that a 20 volt difference at that voltage matters. Is the saw rated for 50 Hz or 60 Hz?
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I agree - that's the crux of the matter. For Europe it is regularly 400V, 50Hz.
 
hillbilly1 said:
Buck/boost transformers are the easy and cheap way to reduce the voltage. Many machine manufacturers offer auto transformers to convert US voltage to European voltages. Check with the manufacturer.
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I have installed buck boost transformers to increase a 208 power to 240 volts single & three phase. Have a question we were told in class to always use three bucks boost transformer on three phase. So long ago the reason for using three verses two buck boost transformers believe was for better voltage regulation. Wondering how many sparkies only use two of them.
 
SOMDJosh said:
The Carpenter where I work Just got a really fancy table saw from Germany with a name plate voltage of 460Vs, we were told to just hook it up to a 480V circuit. The saw is not operating as it should and the techs from the company said we need to supply 460Vs to the saw. I asked the supply house for a 480V Delta to 460V delta transformer and they said it needs to be custom made and its very expensive. Is there another option I can do to solve this or does someone know of a different transformer I can order?
Click to expand...
Always heard that you should be within 5% + or - with power so 5% of 460 volts is 483 volts. I would rather run a motor on a slightly higher voltage then almost 5% under especially on high load days when utility voltage will drop. At times it's difficult to deal with techs who think they know it all. Back in the 1990's while tying in a certain brand of CNC machines in a few machine shops tech constantly blamed problems because I refused to drive in a 8' long ground rod at every machine. I ran a temporary #4 copper wire to a nearby by 3/4" water line to prove him wrong. He then attempted to convince me that ground rods provide a better ground. Ok let's bet lunch on that. Got a 25 watt 120 volt incandescent lamp and first used the copper water line to furnish the grounded conductor and it gave great amount of light. Then disconnected the ground rod wire from a CNC machine somebody else installed and the 25 watt lamp had a very faint glow. He got his meter out and took voltage readings and told him where to stick his genius ground rod theory and to order my lunch. Not 100% sure until I get one of my VFD manuals out but with the over 100 fault codes a lot of them provide they just might have a fault code for line over voltage. First time that I came across a fault then a few seconds later a shutdown due to DC Buss overvoltage threw me for a loop. It was from a 75 HP return fan that was turned off by engineers for some reason while the two think they were 125 HP supply fans on an AHCU were running at over 80% of full speed causing the return fan to rotate fairly fast where the VFD could not restart a motor running that fast in wrong directing that created a high DC Buss voltage. Had to place two supply fans on hand and ramp them down to 20 to 25% full speed for return fan to finally make the motor stop then start up in correct direction.
 
garbo said:
I have installed buck boost transformers to increase a 208 power to 240 volts single & three phase. Have a question we were told in class to always use three bucks boost transformer on three phase. So long ago the reason for using three verses two buck boost transformers believe was for better voltage regulation. Wondering how many sparkies only use two of them.
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Two can be used in an open delta fashion with no problems, unless it has a freq drive, then three is advisable. Especially if the equipment has a neutral, the one leg stays at 120 volts, so you make sure that leg feeds the 120 volt loads.
 
SOMDJosh said:
The Carpenter where I work Just got a really fancy table saw from Germany with a name plate voltage of 460V
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What brand of saw? I have seen a few Holzmann products in a wood shop a few years back, I recall some came as 400V / 50 hz and were able to be rewired to be 230V 50/hz, others were 220V 50 hz. Then they all ran off a frequency converter motor generator set that was started with the dust collection system and generated 240V 50/hz.
Please post a photo of that name plate or the make / model if you need further advice or assistance.
 
I call BS. Either not connected right or something is up with saw. Germany sends a saw to USA for 460V only? Right.... Agree on a frequency check as well as wtf does "not work right" even mean? the words "brown stripe" have very different meanings depending on the context.
 
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