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dhayanandhan
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Engineering Fields - Mechanical Engineering - New Member

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Location: CHENNAI, TAMIL NADU, INDIA.
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PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/17/2009 8:48 AM

I come to know that for VARIABLE FREQUENCY MOTOR DRIVE SYSTEM, the

NON-DRIVE END of the MOTOR is to be fitted with INSULATED BEARING which means the drive end or the coupling side bearing can be of ordinary type. Is it CORRECT.?

The idea of the INSUATED BEARING is to avoid the shaft voltage or current short-circuiting and one side UN-INSULATED BEARING INSTALLATION may cause the probllem. I am of the opinion that both the bearings should be of INSULATED TYPE.

I seek guidance from CR4 MEMBERS, and share their experience and KNOWLEDGE.

Where can I have full details about VFD DRIVES.? What are the Special Characters of the VFD MOTORS.?

DHAYANANDHAN.S,

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lyn
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Join Date: Oct 2008
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#1

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/17/2009 8:54 AM

For the record VFD DRIVE is redundant. Like CRT tube.

Start here for the basics.

Variable-frequency drive - Wikipedia, the free encyclopedia
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msamad
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Join Date: Feb 2009
Location: Houston, USA
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#2
In reply to #1

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/17/2009 11:57 AM

These links are useful in this context:

http://www.est-aegis.com/datasheets/Application_notes-Motors_greater_than_100HP.pdf

http://toshont.com/ag/vfdapplication/ag_12_pwm_bearing_damage.pdf

- MS

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Anonymous Poster
#7
In reply to #2

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

11/18/2009 1:30 PM

Thank you very mch for the excellent refrence.
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Anonymous Poster
#6
In reply to #1

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/28/2009 4:34 AM

You wrote "For the record VFD DRIVE is redundant. Like CRT tube."

Excuse my ignorance, but why do you say that VFD motors are "redundant"?
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JRaef
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United States - Member - New Member Engineering Fields - Power Engineering - New Member

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Location: California, USA, where the Godless live next door to God.
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#3

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/17/2009 11:22 PM

Either end is fine, but only one end. Otherwise, you set up a circulating path and defeat the purpose.

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Anonymous Poster
#4

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/18/2009 7:32 AM

PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR

The Stator as well as Rotor of motors are made up of Magnetic circuit and the heat produced due to Eddy currents should be reduced. The present day motors are of thin Laminations for core as well as for Rotors and reduces the heating effect. You can ask for motors suitable for VFD applications and Manufactured by Kirloskar, Cropmpton. ABB etc.

You can earth the rotating shaft to ground through a carbon brush.

J.N.Karamchetti
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giri
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Join Date: May 2009
Location: Some where on Earth !!!.
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#5

Re: PROVIDING INSULATED BEARING FOR VFD APPLICATION for NON-DRIVE END OF THE MOTOR.

10/19/2009 1:53 PM

pls fin the link....this will serve your purpose..... http://www.usmotors.com/Service/faq17.htm......

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