View Full Version : The smoke stays inside the VFD?

will gilmore
05-03-2010, 08:58 AM
Thanks for everyones advice in the last thread. I got a Hitachi SJ200 2HP VFD.
Motor is Marathon Inverter/Vector duty, 230/460V, 6/3A, 1760RPM, 60Hz, 2HP, SF1.0, Max speed 3600, 3HP 30min duty.

Here is the smokey saga:

Motor is 9 wire. I initially misread the wiring diagram. Proper wiring is 1-7,2-8, 3-9, 4-5-6 together. My initial wiring was 1-7-4, 2-8-5, 3-9-6. Turned on the VFD and the motor turned but was singing and the VFD faulted. Looked closer at the wiring diagram and realized my error. I'm thinking to myself "wow, dodged a bullet there".

Went back fixed the wiring at the motor. Flipped on the power to the VFD and a small curl of smoke started coming from the top of the VFD! Flipped off the power. Checked the wiring about 20 times. I'm affraid to turn it back on. What's going on?

05-03-2010, 09:28 AM
Hi will gilmore

Take a photo of how you have wired the input wiring to the VFD as others have had a problem in this area,with the wiring of the VFD not with the motor, but it still could be your motor that caused the fault in your drive

will gilmore
05-03-2010, 10:40 AM
http://www.gothamchopshop.com/lathe/granite lathe 064.jpg
http://www.gothamchopshop.com/lathe/granite lathe 065.jpg

I had taken the leads off the VFD to measure the resistances between the leads (all the same ~1ohm I think) and resistance to ground (all the same and in Mohms). I think they are back in the same order. I assumed (uh oh) that T1,T2,T3 on the vfd could go to any of the pairs on the motor.

05-03-2010, 11:47 AM
The connections in your first post appear to be standard numbering, if so it looks like you had a couple of windings jumpered (shorted) instead of two in parallel.
Could be the reason for the smoke?

will gilmore
05-03-2010, 11:58 AM
At first I wired 1-7-4, 2-8-5, 3-9-6 (not pictured) this resulted in the motor turning and singing but no smoke.

2nd attempt: 1-7,2-8,3-9,4-5-6 (1st picture) this resuled in smoke.

Are you saying I messed something up with my 1st attempt and it resulted in the smoke on my 2nd attempt?

05-03-2010, 01:02 PM
Providing the VFD was hooked up correctly, that would be my first guess?
It is possible you could have blown something in the first attempt.
I would power up with the motor disconnected and see if any sign of trouble still appears and also if the display shows normal.
Your first attempt would most likely have produced an abnormal high motor current.

05-03-2010, 01:14 PM
Hi will gilmore

There is only some drives that you can wire this way, you can not on this drive jumper
L1 to L2 , this is were your problem is, L2 should have nothing connected to it in single phase wiring of your drive
You will have to send the drive in for repair most likely

will gilmore
05-03-2010, 02:04 PM
Doh! Thanks mactech. The manual was a bit unclear on that point. I thought it said to add one because my VFD was between xxx and yyy. Maybe only xxx and yyy need the jumpers.

05-03-2010, 02:35 PM
You have to check the model suffix type as a couple they suggest you can, I would be very surprised if you did do it and it caused damage as generally the input is to a 3 phase bridge, and jumpering two phases will just parallel two pairs of diodes.
Probably never know what the reason was however?

will gilmore
05-03-2010, 02:50 PM
My 2hp, 230V, 1ph in, 3ph out VFD is SJ200-015NFU

Help me read! page 2-20 of this: http://www.driveswarehouse.com/documentation/Hitachi/SJ200M.pdf

I think the middle diagram is saying SJ200-007NFU to SJ200-037LFU require the jumper from L1 to L2. On page 2-18 they have a chart and -015NFU is between -007NFU and -037LFU so I need the jumper right?

05-03-2010, 03:12 PM
Hi will gilmore

It clearly says on page 57 of the pdf, or 2-19 Wire the inverter input to the supply power

NOT to have L2 connected for single phase

The set of terminals above the main power supply is were the jumper is & you do not need to touch that unless you are using a external braking resistor, You can see the metal jumper between PD1+ & P These terminals are also called L1+ & L2+ on some drives

will gilmore
05-03-2010, 03:36 PM
Fair enough, when I read that I took it to mean do not connect the input power directly to L2. Gotcha. I totally misread the diagram in the manual. Thanks.

will gilmore
05-03-2010, 05:28 PM
Nuts, removed the jumper, applied power, fan comes on display shows ---- a couple of the other lights are on. I think its broken...

05-03-2010, 10:34 PM
Hi will gilmore

There should not be to much damage done, not as bad as some have done they put the input power on the row of terminals above were you did I destroyed the whole drive

will gilmore
05-05-2010, 08:35 AM
where do I send it for repair? I emailed driveswarehouse (where I got it) with no response. I'll call today.

Any other ideas?