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MIKE the DOG
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Join Date: Aug 2009
Location: Texas
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Three Phase Variable Frequency Drive

06/24/2010 11:26 AM

I'm currently using a 240vac Variable Frequency Drive that is in a control enclosure that I supply to a customer. The VFD runs off 240vac single phase ( two hot legs and a ground ) and outputs 240vac three phase for a 7.5hp motor. The question I'm being asked is the following: "VFD is going to Australia, in Australia 240vac single phase is one hot leg and a neutral how will this affect the VFD?"

My initial educated guess is that the VFD will work just fine?

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JRaef
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#1

Re: Three Phase Variable Frequency Drive

06/24/2010 11:55 AM

You really have to check with the specific drive mfr. because on some of them the bridge may not like being grounded.

By the way, hopefully you didn't mean that you are connecting the ground to one of the VFD input power terminals now!

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MIKE the DOG
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#4
In reply to #1

Re: Three Phase Variable Frequency Drive

06/24/2010 1:01 PM

No just connecting the ground to the provided ground terminal of the VFD

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#2

Re: Three Phase Variable Frequency Drive

06/24/2010 12:03 PM

You are correct, it will work fine as long as they don't use the neutral as a ground wire, but a separate conductor to the fisical ground installation.

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PWSlack
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#3

Re: Three Phase Variable Frequency Drive

06/24/2010 12:06 PM

It should be fine.

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MIKE the DOG
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#5

Re: Three Phase Variable Frequency Drive

06/24/2010 1:04 PM

Thanks guys for your all the good answers! I really appreciate and value the information here on CR4

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Doorman
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#6
In reply to #5

Re: Three Phase Variable Frequency Drive

06/24/2010 1:48 PM

MIKE the DOG says you gave good answers, so I will vote you all one!

Nice going guys.

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#7
In reply to #6

Re: Three Phase Variable Frequency Drive

06/24/2010 2:20 PM

Doggone Doorman !? Just when I started feeling I deserved it !

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#8
In reply to #7

Re: Three Phase Variable Frequency Drive

06/24/2010 2:24 PM

Still appreciate it, thanks !

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portugalphilip
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#9

Re: Three Phase Variable Frequency Drive

06/24/2010 4:38 PM

Your initial educated guess is that the VFD will work just fine is correct.

The ground is not part of the circuit.

Ground is for protection only.

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Grochy
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#10

Re: Three Phase Variable Frequency Drive

06/25/2010 12:02 AM

Mike as the other posts have confirmed the vfd should be okay the only troubles we have had over here is nuisance rcd tripping, danfoss is one brand we dont use as they are known to cause problems, SEW are ok. It may pay to check before shipping.
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Users who posted comments:

Anonymous Poster (3); Doorman (1); Grochy (1); JRaef (1); MIKE the DOG (2); portugalphilip (1); PWSlack (1)

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