Previous in Forum: 6KV GEN   Next in Forum: Does Ambient Temperature Affect the Accuracy of IR Scanning Electrical Devices?
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
9 comments
Rate Comments: Nested
satish madriki
Participant

Join Date: Aug 2014
Posts: 4

How to Locate Faulty VFD

01/13/2015 1:42 PM

Hi Everyone .. Sir we use Mitsubishi 3.5kw vfd which is connected to a sew motor and this motors operates based on brake actuation of same make sew .Problem faced is when motor runs in fwd direction current drawn is around 1.5A but in reverse direction it's drawing around 4.5 A as per inverse time characteristics it runs for few seconds and get tripped with O/L fault indication. suspected mechanical obstacles during the movement but nothing found and also its bearing replacement done so then changed the motor along with gearbox also But still problem persisting and at last suspected on malfunction of vfd and changed the same with brand new one. It was running successfully from past 1 day suddenly even this vfd is showing the same as before during forward movement 1.5A and for reverse 4.5A ..... Please suggest me does vfd malfunctions if yes then wat might be the abnormalities that we can locate
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
JRaef
Guru
United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
Posts: 4665
Good Answers: 804
#1

Re: how to locate faulty vfd

01/13/2015 2:15 PM

Is this new and has exhibited this behavior from the outset, or has it been working fine for years and this just started happening?

__________________
 ** All I every really wanted to be, was... A LUMBERJACK!.**
Register to Reply
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#2

Re: How to Locate Faulty VFD

01/13/2015 2:25 PM

Have you tried adjusting the brake so it doesn't grip too tightly?

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Anonymous Poster #1
#3

Re: How to Locate Faulty VFD

01/13/2015 2:45 PM

It's probably on the wall over there.
Register to Reply Off Topic (Score 5)
ozzb
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5197
Good Answers: 266
#4

Re: How to Locate Faulty VFD

01/13/2015 3:54 PM

How are you reversing the motor? Why are you using a brake to control speed? Thats should be a function of the vfd.

__________________
 Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
satish madriki
Participant

Join Date: Aug 2014
Posts: 4
#6
In reply to #4

Re: How to Locate Faulty VFD

01/13/2015 10:53 PM

Sir brake is used for an object to stop at exact location based on stop I/P signal I have confirmed without any load, only by actuating the brake the motor shaft rotates freely in both case rev and forward. Even done the fine adjustement of brake gap setting too.
Register to Reply
ozzb
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5197
Good Answers: 266
#8
In reply to #6

Re: How to Locate Faulty VFD

01/14/2015 7:48 AM

How are you reversing the motor?

__________________
 Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Original_Macgyver
Guru
Hobbies - CNC - New Member

Join Date: Jul 2013
Location: Lost Wages Nevada
Posts: 1578
Good Answers: 55
#5

Re: How to Locate Faulty VFD

01/13/2015 4:18 PM

Check to see if the brake is releasing on both forward and reverse. You may have an issue where the brake is dragging on reverse?

__________________
 Though it does seem he frequently has a Swiss Army knife or Leatherman and a roll of duct tape with him.
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
satish madriki
Participant

Join Date: Aug 2014
Posts: 4
#7

Re: How to Locate Faulty VFD

01/13/2015 11:01 PM

It was spare brake connected to spare motor along with gearbox before this set was put into service trial has been taken to ensure brake actuation was kkk and for ur kind information this has been running from years....
Register to Reply
yashunisarga.n
Participant

Join Date: Jan 2015
Posts: 1
#9

Re: How to Locate Faulty VFD

01/15/2015 8:52 AM

Did u checked by reversing phase sequence......?
Register to Reply Off Topic (Score 5)
Register to Reply
Have a Different Question?
9 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); JRaef (1); Original_Macgyver (1); ozzb (2); satish madriki (2); Tornado (1); yashunisarga.n (1)

Previous in Forum: 6KV GEN   Next in Forum: Does Ambient Temperature Affect the Accuracy of IR Scanning Electrical Devices?

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (74 right now)
Show Members
Advertisement