Please Help with VFD, I Blew a Wire off of Electric Company’s Transformer!

[hamholfarm]

UPDATE: WARNING This explanation and associated pictures depict the WRONG way to hook up this VFD !

Go down to respone Number 7 to learn the correct way !


Hello,

I have a Hitachi SJ200-022NFU2 VFD. I wired it up exactly as the manual stated – “I think”. When I turned the power on – BOOM – and everything went black. The transformer in the front yard blew a wire off of its’ connector! Partial power came back a few seconds later – only back wall sockets worked, but could only power the radio and not radio and small fan!

OK, here’s the situation. The Hitachi SJ200-022NFU2 VFD is a one phase or 3 phase 220V In-Put, 3 phase 220V Out-Put, 3 HP, VFD. I want to run my 2 HP lathe off of it. Here is how I hooked it up: Power from the electric company’s transformer comes straight to my shop, A licensed electrician put in a 200 amp main panel, then ran a 10/3 wire off of a 220V 30 amp breaker next to the spot I would put the lathe in later on. I made up a “power Board” which holds a single phase 220V 30 amp breaker, the Hitachi VFD, and a 220V, 30 amp 3 phase fused switch. I wired in the 220V 30 amp 1 phase breaker, red wire to one input terminal, black wire to the second input terminal, clipped and put a wire nut on the white wire, and attached the ground wire to the ground lug. From the output of the breaker I ran a piece of 12/2 to the VFD; To the top left set of terminals of the VFD, I ran the white wire to what I thought was L1, the black wire to L3, L1 has a jumper to L2 per the instructions, the ground wire to the ground lug on the VFD. Next, I ran a piece of 10/3 from the VFD to the 3 phase 220V 30 amp fused switch. I ran one line from each of the following terminals on the bottom row, right hand side of the VFD: U/T1, V/T2, and W/T3, the ground wire was attached to the ground lug of the VFD. The 3 power wires from the VFD were attached to one each of the 3 input terminals on the 3 phase, 30 amp, fused switch. The ground wire was not properly grounded to this switch. I had no intention of turning on this switch. I was only trying to power up the VFD to see if it worked correctly. The 3 phase fused switch connects to the 3 phase breaker on the lathe and then to an on/off switch. This last breaker and switch were already on the lathe when I received it. I double checked all of my wiring, I thought I had everything hooked up correctly, so I turned on the single phase 220V, 30 amp one phase breaker. There was a huge “Boom” and then everything went black inside the shop. There was a discussion about this very VFD (except I have version 2) on this site on Feb 7, 2007, titled “Apparent issue with SJ200 & Leeson 3ph 2HP motor”. I read it many times to make sure I understood the other persons mistake and references of how to correctly hook up the VFD. I don’t know what I did wrong! Did I fry my VFD? What should I do now?

I really appreciate your help.

There are pictures with descriptions at the following link, please view them and reply.

http://s113.photobucket.com/albums/n...Hitachi%20VFD/



Thank you!

Chip

[Al_The_Man]

I would not expect a wrong connection on the VFD to cause a 30amp breaker to be bypassed and blow a connection off the Txmr.
I would first check the integrity of the 1 phase supply to the 30amp breaker.
When you restore power, disconnect the input to the VFD, leave the 1ph breaker off and check incoming voltage , then switch on the 1ph breaker and so on down the line, lastly hook up the VFD again.
BTW the best practice, is to put the VFD in the lathe enclosure and normally there should be non-fused conductors from the output of the VFD to the motor.
i.e. motor Directly wired to VFD.
Al.

[neilw20]

From my experience with VFDs (10 A 3 phase 0.1Hz - 3000Hz) the data sheet specifically says NOT TO SWITCH THE OUTPUT.

Connect it directly to the load.

Who knows what the switching device bridge (I guess IGBT's) will do if it is not terminated. On the input side, do not power down when motor running (when you get it going, but I suppose a power failure will eventually break this rule). All motor control, fwd,rev,stop,jog and remote speed control must be done as per the device specifications (EXACTLY) otherwise strange things may go bump in the night. There will be many variables to set correctly to get it working nicely. Just follow the instructions. It might have survived.
Put (in parallel) one or two 300W light bulbs in series with the mains input and see what happens. Doing this will save the power pole wiring and may put a bit of light on things.

Get rid of the BIG SWITCH, or put it in the primary side, but you already have a contactor there.

At least using a licensed electrician ensures that the fire will be elsewhere and plenty of current can flow.

[jalessi]

Chip,

Call your electrician friend ASAP!

In order to blow one of the legs off the feed transformer you have a serious problem.

The wiring before the 30 amp breaker is not correct, if it was, the breaker would have tripped!

Jeff Alessi

[hamholfarm]

Thank you for the replies.

I will basically do what each of you has suggested.

1. Jeff - I'm going to call my electrician and have him come out and do a thorough check of the entire system. It is only a few months old, and many of the circuits have not been tested as I am slowly transferring equipment from my "old" and much smaller shop too my "new" and much larger shop.

2. Al - I'm sure it will take him a few days before he can come out to me. It is only him and a helper, and he is sure to have a few jobs already with due dates promised. I will do my best to check the circuit but I will not try power to the VFD until the electrician has been here.

3. neilw20 - I will remove the BIG switch after the VFD and connect the VFD directly to the motor. As far as setting all the "variables", that will be later in the whole start up process. Following the instructions, I was doing an initial power up sequence which is to determine if the VFD was operating properly. Setting the actual run process would have been later on. And as you also suggested, I will have my electrician check the entire system.

Thank you again to each of you for responding with your help.

Chip

[Al_The_Man]

Originally Posted by hamholfarm 2. Al - I'm sure it will take him a few days before he can come out to me. It is only him and a helper, and he is sure to have a few jobs already with due dates promised. I will do my best to check the circuit but I will not try power to the VFD until the electrician has been here.

The models I have used so far, I have been able to power up without motor connected without ill effects, just at initial power up.
Al.

[mactec54]

Hi hamholfam

A lot of help from every one but no one looked at the photo of the drive very close as
you have wired it incorrect your 220v wires should be connected to the same row as the
motor is on L1 L2 L3 next to this is T1 T2 T3 the bottom row of terminals everybody has
been confused with this because they see the metal jumper on the other terminals & think that it is were you have to connect to The problem now is you have wired to were
the braking resistor are to be wired, I hope every body that gets one of these drives reads this

DO NOT CONNECET WIRES WERE THE METAL JUMPER IS OR YOU WILL DESTROY YOUR DRIVE

You also have to run the VFD output straight to the motor you can not have
anything connected between the motor & the VFD most mount the VFD on
the machine so that you can ajust the speed easy I will post a photo

You should have a circuit breaker the right amperage before the drive & can also have a on /off switch as well before your power into the drive this is all
you need & should have.

[Al_The_Man]

Originally Posted by mactec54 you have wired it incorrect your 220v wires should be connected to the same row as the motor is on L1 L2 L3 next to this is T1 T2 T3 the bottom row of terminals everybody has been confused with this because they see the metal jumper on the other terminals & think that it is were you have to connect to The problem now is you have wired to were the braking resistor are to be wired, I hope every body that gets one of these drives reads this

I understood the poster to say he had read the previous post where someone had done exactly the same thing, and hopefully had learned from it!
Apparently this happens quite often when people install these particular drives, I understood Hitachi was going to amend their manuals with clear warning.
Sounds like they still need it.
Al.

[mactec54]

Hi hamholfam

Did you connect the input L1 wire to were the metal jumper was already on the drive
if so this is the wrong row of terminals to connect too I'm just posting again to make
sure that what I see in your photo is what you have done.

As some of the Hitachi Drives do connect to the upper row of terminals but not were
the metal jumper is The metal jumper would be to the right of L1 L2 L3 in this case on
separate terminals with the metal jumper connecting 2 of the terminals for the braking resistor.

The metal jumper is removed only when you add a braking resistor as in most types of drives they have a small built in braking resistor so if you need a larger one that is were
it is to be connected.

You Should also use sheilded cable as this will cut the EMF down to almost zero & ground only one end of the sheild which works better if you ground the
input end of the sheild

JUST REMEMBER EVERYONE THAT BUYS THESE DRIVES & OTHERS DO NOT CONNECT AC POWER TO THE ROW OF TERMINALS THAT HAS THE METAL JUMPER ON

[hamholfarm]

Well, that explains why I blew the circuit!

Now I feel terrible, I have not tried rewiring the correct way, yet, but I have probably blown my VFD.

The manual has several errors in it, and other areas are simply not clear and/or confusing.

My electrician did come out this morning and assured me the main power panel was functioning correctly as was the dedicated line to the breaker prior to the VFD.

Thank you "mactec54" and "Al" for explaining and showing a clear picture of the proper way to hook up this VFD.

I did not move the jumper - it is in the same position as when I opened the box - so I wonder why Hitachi puts the jumper there - it just adds to the confusion!

Can I use a standard RJ45 ended computer patch cable to connect the detachable face plate to the main body of the VFD?

If I did kill the VFD is it worth it to try to get it fixed or is it now a paper weight?

Thanks again for all the help.


Chip


Learning through the school of hard knocks.

[hamholfarm]

I have edited my original post to warn others of my mistake. I certainly would feel terrible if someone did not read this entire thread and used my initial explanation and pictures for their own set up.

Thank you again to everyone for their help, comments, and suggestions. I learned a lot, albeit the hard and expensive way.


Chip

[mactec54]

Hi hamhofarm

I still don't think you understand what I have said in my other posts the Jumper that is in the drives is there for the braking resistor & you can not remove it unless you are fitting a external braking resistor, wires are mounted on the ( 2 ) terminals that the jumper is mounted are on only for the use of the braking resistor pack this is the only time that the jumper is removed & These terminals are not for any AC CONNECTIONS

You could check with Hitachi but when this happens the cost to repair is almost the same as a new drive

If you check the lower ROW of TERMINALS where you put the motor out wires you will see L1 L2 L3 beside them to the left this is were you have to connect the 220 input AC