380v to 480v Transformer

it will always be a headache. try to save money other than doing business with morons

Yup...

was to be 480v 60hz (for the US), but they made it 380v 50hz.

Probably. At least until it burns up from the over frequency and loss of torque.

Tell them that you are no idiot and you know that the machine will run at 5/6th full speed. The only solution other than building a new one, that you will accept, is both a transformer and a VFD big enough to handle this machine so you can generate a true 480V 60Hz voltage. That price tag should scare the heck out of them. Probably cheaper for them to build a new one and find a buyer for your machine.

Surely you meant ".....will run at 6/5th full speed....."? Faster than normal when we are talking about some form of induction motors.

I always thought that 50 HZ motors, ran at a higher speed when on 60 Hz.....if I am wrong, please explain why you are right......thanks.

Excepting Universal motors of course!!

You are correct sir. I was thinking of the American devices going abroad, not the other way around. So, the centrifuge might actually work a bit better without the VFD. (???)

RPM is propotional to frequency.

RPM=120f/P

P=Poles is constant for a particular motor,

f=Frequency

I had brought up the point about the machine running 20% slower, to which they responded that it doesn't matter since I can set the RPM on the machine (its still BS though).

I ordered 3 machines from them for a total of 13k and paid a 30% deposit. Two of them were supposed to be single phase at 110V and the other triple phase at 480V. Instead they gave me the single phase ones at 220V and the triple phase at 380V.

I figured I could ignore the issue with the 220V by just having 220 circuit breakers installed (I already have a split air conditioner thats 220). But maybe I'm wrong about this.

I visited the factory for a week while they taught me how to operate the machines and all went well until after I left and we began discussing how many HP I need for an air compressor, and then it slipped out that the machine was a 380V.

They're not flexing on redoing the machine, so it appears my options are to forgo the 4K deposit I paid (which I really don't want to do) or take it as is with the transformer.

Some clarification on how the machine does it's variable RPM might be helpful. If they already use a VFD, or some kind of electronic motor speed control. then the frequency difference won't matter too much. Try to figure out if the extra transformer losses are acceptable to you in terms of running costs.

BTW To reiterate others, it will run FASTER if it's a directly connected (to input supply) AC motor.

[quote]Some clarification on how the machine does it's variable RPM might be helpful.[/quote]

There is a digital control panel in which you can control the RPMs.

If you are going to lose 4K, then accept the transformer.

My belief is that generally a 50 Hz motor will turn faster on 60 Hz, though I may have it wrong.....

Do you feel that the speed difference, either way, will make a difference?

If yes, assuming that it is not direct drive for a moment, a new pulley and belt will correct the speed differences....

As I haven't a clue what the machine is, its hard to make judgments....

50 Hz motor on 60 Hz, will usually run a tiny bit cooler as well if I remember correctly.

Most motors nowadays are built for both frequencies anyway....and marked as such. How about checking?

Tell them that you will be "posting" the true facts on the internet which make affect future sales adversely.....if you have to take the transformer, you want a 20% discount as well......

What does your purchase order or their quote or the contract you signed say about payment and terms? I learned very early on to read the fine print and still do to this day, even with suppliers I have been dealing with for years.

You may have an out to get your deposit back.

More transformer means more transmission losses, it hits your pocket bad in long run. More parts, more probability of defects and maintenance.

Should be no problem with the proper frequency and voltage converter....You'll need somebody that knows what the're doing on hand to test the setup and verify proper operation....

http://www.frequencyinverters.org/60hz-to-50hz-frequency-converter-985275.html

wait a month.....another China bargain will be a thread

I would contact a Chinese trade lawyer representative type person, these people can succeed where others fail...

http://harrismoure.com/practice-areas/international-law/china-law/

With the transformer you will supply 480V/60Hz, and machine will work fine.

RPM is not an issue as vendor state that speed variation is provided as process control.

Except for larger space and cabling and some transformer losses, yours is not a big issue , as such things do happen in industries, for the reason of overlooking at the time of specifying and approving documents.

Hope, people in this discussion do not mind my comments,

how will a transformer change frequency? I don't know that trick

Dear ,

Somewhere in discussion , it is mentioned that machine is provided with Speed Variable drive control,

BR

Jeez... you guys are worried...??

The UK has just ordered a NUCLEAR REACTOR to be made by the Chinese and the French.

What happened to British heavy industry? Didn't we start the industrial revolution...?
Oh I remember... poor management and lack of investment... then they blamed it on the unions and sold the whole workforce down the river (when they weren't coercing the police into whacking them on the heads with batons).

And still people think Maggie Thatcher was a great PM.

On the plus side... the Chinese will get it wrong, but the French will never finish it anyway so it won't matter.

Del

DEAR LANDISMANTLER SIR,

In case you share documnets like drawings etc, PO details, equipment function etc, I can assist you in this and any other case.

Best Regards,

Sharad

CR4 ADMIN: Removed phone number. Do not post phone numbers or email addresses. The CR4 Admin will delete all phone numbers and email addresses posted in threads or comments. You can share this information via the CR4 internal messaging system.

I've heard stories like this many times before.

I've heard stories even worse than this, such as the American mold company owners being held hostage inside the factory by the workers based on a rumor about some departments being reduced in manpower, then the vendors barricaded the plant gates with trucks because they didn't want anything to enter or leave the factory until they got paid, managers were stealing the computers and sneaking out the back door with them. And with all that, the Chinese police refused to do anything, claiming that it was 'just a labor dispute.'

I've also heard some good things, about how someone ordered a machine from China and got exactly what was described on the spec sheet.

Also, I've seen two machines come in to the plant from China, and among the problems was the complete miswiring of the control panel, as well as the worst possible location for the panel. These machines had a rotating carousel for moving and processing the parts, and an integrated sorter bowl on a raised platform next to the carousel. The control panel was on the side of the platform facing the carousel: you had to reach over rotating, spinning components, and then down under the feed track, just to get to the controls. As to the wiring: It had a Start and Stop Button, but if you released the Start button, the machine would lose power, and the Stop button only worked while the Start button was actively pressed. The relay that was supposed to be the latch of the Start/Stop setup was instead used to break the power connection on BOTH the Hot and Neutral legs of the 110VAC device⁽¹⁾.

From what I've seen, it would appear that there are as many reputable people in China as there are in the USA. Not by percentage of the population, by head count.

Notes:

1. For those outside the US: In America, the standard for 110VAC systems is to only break connection on the Hot leg, as the Neutral stays connected all the way back to the supply panel, where it is bonded to Earth ground. I guess it's analogous to the PEN conductor seen in some 3-phase systems, since the supply panel is fed 220VAC split phase in a Hot-Hot-Neutral configuration.
   

BUY AMERICAN! Everybody complains about the Chinese, and then they continue to buy Chinese products. We're doing it to our selves. If everybody continues to buy Chinese, then the next thing you buy should be Rosetta Stone to learn Chinese! I don't believe the question contained enough information, thus all of the answers were speculative!

For the record, I do *NOT* endorse rubbing animal genitalia against peoples faces, or having them shoved down people's throats. That was a metaphor that went of into a strange, dark place all on its own, I did not intend to go there.

It may be possible to take the motor to a competent motor repair shop and have it rewound for the voltage and frequency you need. Ed