Apparent issue with SJ200 & Leeson 3ph 2HP motor

[haysys]

Hi All,

Prior to the recent holidays, I acquired a Hitachi SJ200-022NFU (capable of accepting 1 and 3 ph line power) and a Leeson 2HP 3ph 3400RPM motor.

I have 240 1ph service into the shop via a subpanel breakered at 60A at the main panel. Until now, the breaker feeding the subpanel has never tripped.

I connected the line and load wiring precisly as defined in the manual (2 legs of the 240 line power going to L1 and L2 and neutral going to the N/L3 lug while the VFD to motor connection is U to U1, V to V1, and W to W1). I also have the chassis ground of the motor connected to the chassis ground of the VFD. As my line power receptacle does not currently have a ground lug, I left the line side of the VFD ungrounded. I'll get a ground wire and appropriate recptacle prior to actual install and operation.

After double checking my connections, I plugged the power plug into the wall socket and shop immediately went black. None of the local subpanel breakers tripped, but the the 60A breaker did. This was an instantaneous, do not pass go event.

I have since looked over everything again, and all connections seem to be preceisly as they need to be. I have checked for shorts in all of my cables and plugs--all are as prescribed. I also checked the 240 circuit and everything checks out voltage wise.

I am stumped and unsure what to do next. I'm reluctant to plug it in again because I have changed nothing since the trip. I could sure use some advice. I am definitely out of my element here.

Thanks,

David

[Al_The_Man]

I have never heard of connecting a VFD up with the neutral when using 1 ph, I think if you check the manual, the L1 & L3 is used for the 240vac, you may need to jumper the L1 & L2 terminals, Also Do you have a jumper in place now?
Al.

[haysys]

Well... that would explain my problem wouldn't it. I feel absolutley stupid.

There is indeed a jumper between L1 and L2 and I heartily questioned that--the idea of connecting the two legs of 240 across the jumper defied my understanding of what made sense. But the docs are quite clear that the Jumper must be in place... and I have opinions about people who blindly follow along without questioning. Duhhh...

And indeed I did not intepret the instructions to hook the 2nd leg to N/L3. There were no examples for connecting 1ph power. I did just reread the docs and it does indeed say (in bold no less):

"...for single phase power, terminal [S/L2] will remain unconnected." Now it makes sense.

One final question then: Is the neutral connected to anything? Or does it just float?

Thanks for your attention Al. You have answered hundreds if not thousands of questions here, and I'm quite certain that we all greatly appreciate the energy and knowledge you so generously share.

Thanks!!!

David

[mactec54]

Hi you sure do have a problem you my have fryed the drive as well
The L1 & L3 are what you have to use for your single PH 240 input
L2 you do not connect any thing to it

Some drives L1 can be jumpered to L3 but I'm not sure with your drive
Yaskawa you can

The neutral was one of your problems as you created a dead short
and do not jumper L1 & L2 that to could be a dead short

You can use the Neutral as a ground wire if you do not have a ground but put some green heat shrink on it

Do not run the drive without a ground to the power source you are just
asking for trouble or Electrocution I'm surprised that AL The Man did not say
this by wiring this way you made your whole machine live with no Ground to
protect you.

[haysys]

Mactek,

Thanks for your response.

Seems like what you and Al said are in contradisction. L1 and L2 have a jumper. As I said in my second post, the docs do say "L2 will remain disconnected".

Anyone else withan SJ200 powered with 1ph?? How did you connect it???

Thanks,

David

[Al_The_Man]

Originally Posted by mactec54 You can use the Neutral as a ground wire if you do not have a ground but put some green heat shrink on it Do not run the drive without a ground to the power source you are just asking for trouble or Electrocution I'm surprised that AL The Man did not say this by wiring this way you made your whole machine live with no Ground to protect you.

I did not allocate using without ground, but you do NOT use neutral as a ground wire, ever, this violates the E.Code.
In fact you do not use neutral at all in VFD installation.
The manual states using L1 & L3 for the 240v 1ph. The L1 & L2 are jumpered to allow a bit of extra DC capacity on 1 ph.
The ground is connected in the usual way to the ground lug.
By having a short circuit across the 240v, you probabally blew the breaker before any damage was done.
Al.

[JRaef]

Connection of the L1 and L2 with a jumper is unnecessary, it gives you no "extra capacity" since all the AC input does is provide the raw power for conversion to DC. The capacity of those 2 diodes will be greater, but the total input capacity is still dictated by the other 1/2 of the circuit anyway, so it makes no difference. They recommend making that jumper connection just to satisfy the people who insist on connecting wires to unused terminals, PRECISELY so that they are not compelled to connect the neutral! Now that you have, you most likely blew the input diodes, i.e. your drive is toast. Sorry for the bad news. The only possible saving grace is if by some miracle, the breaker cleared before the diode popped. Highly unlikely though. In that world, breakers are painfully slow.

[haysys]

Thanks Al,

Understood and thank you. I'll hook it up tomorrow and let all know if the breaker did the additional job of protecting the unit.

Regards,

David

[mactec54]

Hi I did type it wrong and I changed it to L1 & L3 for these Hitachi drives should be connected for 240 V single PH and AL you can use any wire you want as long as it is correctly colored or marked so it is clear what that wire is, this does not Violate any codes.Also as J Raef has said you do not have
to jumper L1 & L2 for it will have no gain

Yaskawa VFD Drives are L1 & L2 for single PH

[Al_The_Man]

The blocking action of a 3 phase bridge should cause no conduction from live to neutral if a neutral was so connected to a phase input.
My point about the ground was that you violate the code if you use the neutral as a ground.
The system neutral should be only grounded at source, and this applies to local supplies where a local neutral is set up.
The only reason I mentioned the link was to quote the manual for David's information.
It probabally does not matter what pair you use, as the input usually enters to a 3 phase bridge, the alternative is where there is a 1 phase ac control source connected to a particular pair.
Al.

[haysys]

Hi all...

I went to the shop and hooked up everything from scratch, with the two legs of my 1ph 240 to L1/L2 (jumpered) and L3. I clipped and wire-nutted the neutral wire. I also ran a dedicated wire from the VFD ground to Earth ground. The 3ph motor is hooked up as previously stated (U,V & W plus ground).

I plugged the VFD in and... (drum roll) the breaker tripped again.

So unless anyone has any other thoughts, I suspect I cooked the VFD. I think I'll call Hitachi tomorrow, bare my soul, and see what can be done.

Thoughts???

Thanks again,

David

[Al_The_Man]

Doesn't sound good, try powering up without the motor connected, just to confirm if it is the supply input problem.
Al.