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MrLeifTBM
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Join Date: Aug 2009
Posts: 4

480V 60Hz to 400V 50Hz,how to do?

08/29/2009 10:43 AM

Hello!

I have a machine that is made for Europe 400V 50Hz 8.5Kw but the machine will be connected to supply that are 480V 60Hz, this is a problem. How can I in a fast way reduce the Voltage and the Hz? Is a transformer the correct answer, if YES, what kind of transformer do I need?
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uticobala
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Join Date: Apr 2009
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#1

Re: 480V 60Hz to 400V 50Hz,how to do?

08/29/2009 10:50 AM

Voltage we can stepdown by using stepdown transformer. but frequency we cannot reduce by using transfomers. only way you have to select VFD drive that will solve your problem.
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MrLeifTBM
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#2
In reply to #1

Re: 480V 60Hz to 400V 50Hz,how to do?

08/29/2009 11:55 AM

Hi, and THX.

You meen that I need a step down trf from 480V to 400V, correct?

VFD for decreasing the Hz 60 to 50, correct?

Thx for a reply...
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devitg
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#3
In reply to #2

Re: 480V 60Hz to 400V 50Hz,how to do?

08/29/2009 4:12 PM

What machine are you talking about???

Guess it is a electric oven by heaters , you can use it in either 50/60 HZ.

But if it have motors,

  1. if direct coupling , it will run at 60/50 or at 120% speed, this will be for a refigeration hermetic or semihermetic compressor, condensers fan, motor-pump and so on, so you will have 120% of the rated cooling power, so you can fit , if need, by the VFD to down speed
  2. if chain, or belt , the same , but you can fix change one of the pulley.
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MrLeifTBM
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#7
In reply to #3

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 7:38 AM

HI,

It is actually a Karcher Jetwasher HDS 1195 S Eco that I got from my HQ, and they sent me a 400V 50Hz while we on board the vessel have 480V 60Hz.

I just made a quick test, water connected and all system was OK ready for run, the motor protection is tripping at the same time I turn on the breaker on the jetwasher.

Pump is not jammed as it is turning maybe 2 revs...and then trips.

Leif
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mjb1962853
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Engineering Fields - Electrical Engineering - Analog and Digital Circuit Design Engineering Fields - Electromechanical Engineering - Transformers, Motors & Drives, EM Launchers Engineering Fields - Engineering Physics - Applied Electrical, Optical, and Mechanical

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#4

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 5:23 AM

If a motor application, you should correct both voltage and frequency. I suggest a VFD similar to this one:

http://www.driveswarehouse.com

Check suppliers in your area for best new pricing and also check for used VFD's sold on Ebay. These usually work fine and cost a lot less than new.
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rakesh_semwal
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India - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

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#5

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 5:34 AM

With a very simple logic for a motor load -

more is voltage more is the current

More is frequency less is the current

Perhaps you don't need to change any thing if the machine is made of motors and transformers, (no heaters and bulbs etc), and this machine would work fine on 480V 60Hz,in case it has bulbs and heaters etc you can separate out them and heaters run with separate line coming from small step down transformer.

Regards
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MrLeifTBM
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Join Date: Aug 2009
Posts: 4
#6
In reply to #5

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 7:37 AM

HI,

It is actually a Karcher Jetwasher HDS 1195 S Eco that I got from my HQ, and they sent me a 400V 50Hz while we on board the vessel have 480V 60Hz.

I just made a quick test, water connected and all system was OK ready for run, the motor protection is tripping at the same time I turn on the breaker on the jetwasher.

Pump is not jammed as it is turning maybe 2 revs...and then trips.

Leif
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InstrumentKyle
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Join Date: May 2009
Location: Ontario, Canada
Posts: 21
#8

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 10:32 AM

Most freq drives have an input voltage range. I just looked at an Allen-Bradley Powerflex 700 which has an input range of 432-528 and O/P of 0 - 460. The frequency of course is set at your desired value. Call AB, they tell you exacly what is required (it will likely be off-the-shelf).
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capblanc
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Location: Mallorca, Spain
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#9

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 5:48 PM

Hi Leif,

At 2,350 GBP (3,820 USD) it doesn't make sense to play with conversions. Just get HQ send the correct unit and you drop off the one you have the next time you pass HQ or a sister ship that can drop it off for you.

If that option is not available then try Karcher for the correct motor and any other components that are sensitive to the supply. It will probably be cheaper, easier and you will still have a portable machine that you can move to the place you need to clean.

Regards

Chas

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JRaef
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United States - Member - New Member Engineering Fields - Power Engineering - New Member

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#10

Re: 480V 60Hz to 400V 50Hz,how to do?

08/30/2009 8:48 PM

An AC motor works by creating torque at a speed dependent upon the incoming AC supply. The work you do with it is based on both the speed and torque. The torque is dependent upon a ratio of voltage and frequency (called the V/Hz ratio) that the motor designer selected. Using something far outside of a relatively narrow bandwidth of voltage and frequency affects the torque and speed of the motor.

So for your 500V 50Hz pump motor, the V/Hz ratio s 400/50 or 8.0:1, and if you connect it to a 480V 60Hz supply, the ratio is... 480/60 = 8.0:1! So connecting the motor to the 480V source is not the problem, it is perfectly acceptable. Even f your supply is 460V, that is within 10% and completely acceptable.

What IS a problem however is the speed and power that it now consumes. The speed will increase by 20% because of the higher frequency (60/50 = 1.20), so consequently because the torque remains the same (because you have the correct V/Hz ratio) but that higher speed, the motor output kW capability increases as well by the same amount. So now your 8.5kW motor, when used on 480V 60Hz, becomes a 10.2kW motor (8.5 +20%).

But wait, there's more. If you have a centrifugal pump, the flow, and thereby the power that the PUMP consumes, varies by the cube of the speed change. So now your pump, where it was consuming no more than 8.5kW, will require as much as 14.7kW if left uncontrolled! So bottom line, if you did nothing else, you potentially have 14.7kW of load on a motor not capable of delivering more than 10.2kW and the result is that it will over load.

So why is your motor now tripping almost instantly then instead of a slow overload trip? That's because from an inrush (magnetizing) current standpoint, the protection devices that were originally selected for an 8.5kW 400V motor are seeing the inrush current of a 10.2kW 480V motor and likely tripping off on instantaneous trip.

So what to do?

  1. Restrict the flow from your pump. Even though the higher speed in causing the pump to be CAPABLE of pulling more power, that is because the FLOW is increasing by the cube of the speed change. Power follows flow, so restrict the flow to what it was when the motor was running at 50Hz and the power requirements will drop. A simple valve can do this.
  2. Adjust the motor protection devices to accommodate that higher inrush (magnetizing) current because of the new input power source. Assume it is about 20% higher than it would have been before. If your motor protection device does not have an adjustable instantaneous trip setting, you may need to buy one that does.
  3. Option 3 is to buy a VFD. No need to get a transformer or anything like that, you can simply program the VFD to produce a maximum voltage of 400V at a maximum frequency of 50Hz and all will be right with the world. The VFD will inherently deal with the inrush current issue.
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Apps Man
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#11

Re: 480V 60Hz to 400V 50Hz,how to do?

08/31/2009 12:50 PM

You will need a frequency converter that also steps the voltage down, FCX systems at FCXINC.COM is a company that builds frequency conversion equipment. You can contact them to see how much one will cost vs. just scrapping the old machine for a 60hz one.
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Anonymous Poster
#12
In reply to #11

Re: 480V 60Hz to 400V 50Hz,how to do?

08/31/2009 6:08 PM

Wow, you mean NOBODY else in the whole world makes inverters besides this FCX outfit? Huh, I thought they were a little more common...

By the way, your suggestion is all wrong anyway. FCX makes inverters for aircraft ground support systems, i.e. 400Hz output. SERIOUS overkill for a little thing like this, even if you can turn the frequency down to 50Hz.
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Apps Man
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#13
In reply to #12

Re: 480V 60Hz to 400V 50Hz,how to do?

09/01/2009 9:45 AM

You are the one that is wrong FCX does makes 60 to 50hz converters check out their website. Yes, there are other companies out their but I know FCX makes a quality product and no I do not make money or have a relationship with FCX. In the future keep your comments to yourself.
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Anonymous Poster
#14
In reply to #13

Re: 480V 60Hz to 400V 50Hz,how to do?

07/07/2010 2:19 PM

called this company and a they wanted for a 480 volt to 400 volt converter, 25 htz.

a whopping 31,500 dollars. way over priced. i can use 3 buck transformers for about 500 dollars
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Anonymous Poster
#15
In reply to #14

Re: 480V 60Hz to 400V 50Hz,how to do?

07/07/2010 2:26 PM

25 kva, i meant
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Apps Man
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Join Date: Dec 2007
Location: Chicago, IL, USSA
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#16
In reply to #14

Re: 480V 60Hz to 400V 50Hz,how to do?

07/07/2010 3:52 PM

Not to convert frequency, the buck boost will only change the voltage but if the load can operate at 60hz then you are ok. As the other guest said there are other companies that make frequency converters just google it and see what comes up.
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Anonymous Poster
#17

Re: 480V 60Hz to 400V 50Hz,how to do?

08/01/2010 10:41 AM

If U have purchased a Machine With 400 V 50 Hz. the it will work very fine on 480 Volts 60 Hz no need of frequency converter. As per the Formula

400 x 60 / 50 = 480 Volts

On 60 Hz its requirement of Voltage is 480 Volts. With the change in the Frequency the Voltage will Change As per the frequency cycle.
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dhayanandhan
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Engineering Fields - Mechanical Engineering - New Member

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#18

Re: 480V 60Hz to 400V 50Hz,how to do?

07/29/2014 1:12 PM

Dear Mr.

This topic was discussed few times in this Forum.

Pl. open the link below and you will find more details.

http://cr4.globalspec.com/search/sitesearch?do=show&srchobjs=t%2Cc&order=asc&fs=12&sort=textmatchrank&srch=480V%2060Hz%20to%20400V%2050Hz%2Chow%20to%20do

DHAYANANDHAN.S
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Users who posted comments:

Anonymous Poster (4); Apps Man (3); capblanc (1); devitg (1); dhayanandhan (1); InstrumentKyle (1); JRaef (1); mjb1962853 (1); MrLeifTBM (3); rakesh_semwal (1); uticobala (1)

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