AC Drive/VFD Getting Faulty Again and Again

5 comments

Rate

aks5884 Participant Join Date: Sep 2013 Posts: 3	AC Drive/VFD Getting Faulty Again and Again 10/25/2014 4:42 AM
	I am using 6 nos. Emerson Uni SP 1405 vfd which are connected side by side in the panel. There is around 75mm distance between these drives. There is a frequent failure in the drive time to time. Sometimes its control card get damaged & sometimes its IGBT get damage. I have checked the supply and earthing & everything seems to be ok. Generally observed that during the initial operation only these drives get faulty. Most of the time drives are in standby condition only.
	Register to Reply
	Pathfinder Tags: VFD/AC drives problems

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

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 Join Date: Sep 2006 Location: California, USA, where the Godless live next door to God. Posts: 4665 Good Answers: 804	#1 Re: AC Drive/VFD getting faulty again and again 10/25/2014 11:42 AM
	The possibilities are very numerous, but most of the time if a problem causes IGBT failures, especially repeatedly, it will come down to inattention to details on how the VFD is connected to the motor. You said "I have checked the supply and earthing and everything seems to be okay", but was that about the supply only? It is the output side that connects to the IGBTs, supply issues rarely affect them. If you want meaningful help, describe your load circuit in detail, ALL details, meaning distance, load protection dvices, type of cable, conduit if any, grounding, shielding if any, routing with other drive outputs if any, etc. etc. etc. __________________ All I every really wanted to be, was... A LUMBERJACK!.
	Register to Reply Score 1 for Good Answer

GW Guru Join Date: Oct 2006 Location: Surrey BC Canada Posts: 1571 Good Answers: 42	#5 In reply to #1 Re: AC Drive/VFD getting faulty again and again 10/26/2014 1:17 PM
	GA. Age of drive? How long in service? Length of motor cable runs, type of cable, common mode chokes, output reactors, motor cable termination circuits, etc. There is much published on successful motor connections to a VFD, and it is associated strongly with motor cable lengths and cable type.
	Register to Reply

dhayanandhan Guru Join Date: May 2008 Location: CHENNAI, TAMIL NADU, INDIA. Posts: 1851 Good Answers: 65	#2 Re: AC Drive/VFD getting faulty again and again 10/25/2014 12:53 PM
	Dear Mr.aks5884, Pl. check the following. 1.What is the heat liberated from the VFD and cooling by Heat Removal. The Heat liberated while conversion from AC - DC - AC should not exceed 6 to 7%. 2. What is the cumulative effect of Harmonics, i.e., 5th, 7th 11th and 13th Harmonics. This should not exceed 8% of the Fundamental Voltage if 690 is the VFD voltage. 3. Pl. check the earthing and it should be 2.5 times to that of Normal Drive. Ensure INDEPENDENT/DEDICATED EARTHING is provided. Pl. inform this Forum - how the problem is solved. DHAYANANDHAN.S
	Register to Reply

jmueller Guru Join Date: Jul 2006 Location: Eastern Kansas USA Posts: 1503 Good Answers: 128	#3 In reply to #2 Re: AC Drive/VFD getting faulty again and again 10/25/2014 10:26 PM
	The concern about heat is valid. Also verify that the motor is earthed directly to the earthing terminal in the drive and not to the cabinet. The request for all the details about the connections is also valid. There are many factors that can go wrong, even though they usually don't. If you want our help, be patient with our questions. --JMM
	Register to Reply

brich Guru Join Date: Oct 2009 Location: sometimes Wales,UK.. was Libya, now Oman! Posts: 1715 Good Answers: 117	#4 Re: AC Drive/VFD getting faulty again and again 10/26/2014 4:53 AM
	simple answer, call the manufacturer. I work on VFD's and I can solve a fault, when I'm connected to the drive remotely or when in front of it. Distance fault finding via email.. impossible!! __________________ The square root of nothing is what you make it!
	Register to Reply Score 1 for Off Topic

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

brich (1); dhayanandhan (1); GW (1); jmueller (1); JRaef (1)

	Got Something to Say?
	Ask a Question Start a Discussion

	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 (60 right now) Show Members