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220vac Single Phase To 380vac 3 Phase Inverter For Lathe/milling Machine


jarryd

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Hi

 

I have a question, is it possible to use a single phase 220VAC supply and use an inverter or VFD to convert to a 380VAC 3phase power, to run a milling machine and a lathe separatly ?- How much current will the single phase be drawing, the lathe has a 380VAC 5HP motor and the milling machine is a 380VAC 3HP motor, also if there is an inverter can you wire it up directly to the machine as if it was natural 3 phase 380VAC input

 

please post links to inverter or VFD's if possible

 

Thanks

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It is possible to use an inverter which is designed for single phase in and 3 phase out as the incoming supply first converts into DC then AC. in this case, the single phase input current would be 1.73 times > then 3phase output current. So it is not a case, just a selection of inverter.

The question mark is to run two different rating motors through one VFD. Although I don't have such experience ever but for me it is possible.

lets wait for comments from other experienced engineer.

 

 

"Don't assume any thing, always check/ask and clear yourself".

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It is possible to use an inverter which is designed for single phase in and 3 phase out as the incoming supply first converts into DC then AC. in this case, the single phase input current would be 1.73 times > then 3phase output current. So it is not a case, just a selection of inverter.

The question mark is to run two different rating motors through one VFD. Although I don't have such experience ever but for me it is possible.

lets wait for comments from other experienced engineer.

 

AB2005:

 

Original Question .... (perhaps you missed this) .... <_<

"...is it possible to use a single phase 220VAC supply and use an inverter or VFD to convert to a 380VAC 3phase power,"

 

Consider, VFD's are not voltage multipliers..... 220 in ..... 220 out ..... 380 in........380 out.

 

 

 

There have been (and are) applications where the VFD sources the primary of a step-up transformer .... but these are specail cases and are custom engineered (designed), as is the transformer.

 

 

 

It is possible to run two different motor ratings from one VFD.... provided that the VFD is sized correctly and that each motor has its own overload protection and that the motors are stopped and started by the VFD... i.e., started from zero and run up to speed, and either stopped by decelerating to zero, or shutting off the VFD output (coast-to-stop mode).

 

Also, using a VFD as a fixed operating point power source .... and then using the existing starters to connect the motors onto and disconnect the motors from the VFD output

is not a wise practice. There are many reasons why this is not advisable.

 

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Hello Jarryd

 

If your mtor is connected in star for 380 volts (common for motors smaller than 4KW, then you can reconnect it in delta for 220 volts three phase and use a standard single phase input three phase output VFD to control it.

 

Best regards,

MArk.

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Consider, VFD's are not voltage multipliers..... 220 in ..... 220 out ..... 380 in........380 out.

 

Dear jOmega,

 

We have such small VFDs which are connected with single phase power source and drive a three phase motor. In this case, input current is > than output current.

Jarryd want to run two 3phase motors via an inverter whose input power is 220V single phase. Please point out where am I mistaking to understand the question?

"Don't assume any thing, always check/ask and clear yourself".

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Hello AB2005

 

The VFD does not increase the voltage.

Rectify and filter the incoming AC and you get DC.

Chop up the DC at 100% modulation and you will get a little bit less on the AC output except if your input rectifier/filter is acting as a peak rectifier rather than an average.

230V single phase input VFDs produce 230V three phase output voltages.

To get 380V three phase output, you wouldneed to add a step up transformer.

 

Best regards,

MArk.

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Dear jOmega,

 

We have such small VFDs which are connected with single phase power source and drive a three phase motor. In this case, input current is > than output current.

Jarryd want to run two 3phase motors via an inverter whose input power is 220V single phase. Please point out where am I mistaking to understand the question?

 

 

 

AB2005 .... Jarryd's original question was :

 

"I have a question, is it possible to use a single phase 220VAC supply and use an inverter or VFD to convert to a 380VAC 3phase power, to run a milling machine and a lathe separatly ?"

 

Jarryd is asking if he can supply a VFD with Single Phase 220 VAC INPUT and get Three Phase 380 VAC OUTPUT ... to run his milling machine ...

 

As his question states ..... he wants to convert single phase 220 VAC to three phase 380 VAC

 

What you described in your reply is converting the same voltage from single phase to three phase. i.e., 1φ- 220vac to 3φ 220vac or 1φ 380vac to 3φ 380vac ....

 

That is not the same as what Jarryd wants to do, i.e., convert 1φ 220vac to 3φ 380vac.

 

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Hello AB2005

 

The VFD does not increase the voltage.

Rectify and filter the incoming AC and you get DC.

Chop up the DC at 100% modulation and you will get a little bit less on the AC output except if your input rectifier/filter is acting as a peak rectifier rather than an average.

230V single phase input VFDs produce 230V three phase output voltages.

To get 380V three phase output, you wouldneed to add a step up transformer.

 

Best regards,

MArk.

 

 

Mark, as stated in previous post, transformers used to step-up the ouput voltage from a VFD are a Special Design.

 

Catalog and/or off-the-shelf — fixed voltage & frequency — transformers are NOT suitable for stepping up the VFD output voltage as they are designed to operate on Sine Wave power; which the VFD output is not.

 

Whereas utility power is true sine wave generated, the output of a VFD is switched DC... controlled so as to simulate AC.

 

Kind regards,

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Hello AB2005

 

The VFD does not increase the voltage.

Rectify and filter the incoming AC and you get DC.

Chop up the DC at 100% modulation and you will get a little bit less on the AC output except if your input rectifier/filter is acting as a peak rectifier rather than an average.

230V single phase input VFDs produce 230V three phase output voltages.

To get 380V three phase output, you wouldneed to add a step up transformer.

 

Best regards,

MArk.

 

Thanks. Now understood where I was mistaking.

 

"Don't assume any thing, always check/ask and clear yourself".

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  • 3 years later...

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