3 Phase VFD supplied by single phase - de-rating

[Smouser]

Now that most of us are suitably confused we can continue with the 3-phase VFD problem.

I powered the unit up today on single phase power.

I then connected a motor to it, set some parameters for the motor and tried to run it.

As expected, I ran into an error/alarm.
A5031 - Drive is not ready for operation, eg, due to low DC voltage. Check input power supply.

I have not yet found a parameter I could change for the VFD to ignore the alarm/remove some protection on the drive so that the VFD will run the motor with a single phase input.

There was not enough time to investigate further, it might even be that this VFD is unable to run from a single phase input supply at all. However, I know some 3 phase input ABB ACS355 drives can run from a single phase supply (from the ABB de-rating document).

Does anybody know of a forum where ABB VFD experts hang out?

 

[Anguz]

There is a parameter.. we gad some abb 3 phase ones at work that were suffering due to supply volts and bringing in the low bus alarm....we had an engineer log in somehow and get to menus that i hadnt seen before to nobble the alarm... quite a few years ago so no clue how he did it.... will message one of our contractors monday he may know
Got the abb drive model number?

 

[Pete.]

You could try bumping the input with an autotransformer like I do with my DC drive, but you'd need a pretty big one. Something like a 5kw yellow power tool transformer. That'll get your input voltage up around 350V. There's another way which involves messing with the internal capacitor connections but I can't find the details.

 

[carbon]

From the model number ACS 355-03E-15A6-4 the 03 specifies it to be 3 phase and the 4 demotes a voltage range of 380-480vac. Also from the manual U1 and V1 are used for single phase input for the relevant drives.

Parameter 2006 relates to under volt control and can be disabled by setting to 0 but I’m not sure if this will help

From this Manual

 

[Smouser]

There is a parameter.. we gad some abb 3 phase ones at work that were suffering due to supply volts and bringing in the low bus alarm....we had an engineer log in somehow and get to menus that i hadnt seen before to nobble the alarm... quite a few years ago so no clue how he did it.... will message one of our contractors monday he may know
Got the abb drive model number?

Thank you, that will be great!
Hopefully, the engineer can explain how he got to the menus/which parameters to change.

Model number: ACS355-03E-15A6-4

You could try bumping the input with an autotransformer like I do with my DC drive, but you'd need a pretty big one. Something like a 5kw yellow power tool transformer. That'll get your input voltage up around 350V. There's another way which involves messing with the internal capacitor connections but I can't find the details.

Thanks Pete. That is an option I could consider if I can't get it going via other means.

From the model number ACS 355-03E-15A6-4 the 03 specifies it to be 3 phase and the 4 demotes a voltage range of 380-480vac. Also from the manual U1 and V1 are used for single phase input for the relevant drives.

Parameter 2006 relates to under volt control and can be disabled by setting to 0 but I’m not sure if this will help

From this Manual

Thanks carbon. I have changed the 2006 parameter but it did not seem to make a difference.
I have some ACS 355-01 drives, specifically made to work with a single phase ~230v input but as you know this one is an ACS 355-03 drive hence the problem.

 

[Agroshield]

I have some ACS 355-01 drives, specifically made to work with a single phase ~230v input but as you know this one is an ACS 355-03 drive hence the problem.

Please, did you see his suggestion above: "also from the manual U1 and V1 are used for single phase input"? To me, your picture looks like you have wired it up using U1 and W1, so maybe try U1 and V1.

 

[Smouser]

Please, did you see his suggestion above: "also from the manual U1 and V1 are used for single phase input"? To me, your picture looks like you have wired it up using U1 and W1, so maybe try U1 and V1.

Good spot.

I will try it.

 

[Smouser]

We didn't really expect it would be that easy.

A big fat no

 

[Smouser]

@Anguz did you have any luck with the engineers?

 

[Anguz]

he hasnt replied yet.....
he hasnt actually seen the whatsapp... will ring him tomorrow to see if he still works

 

[minimutly]

I would try a 240 110 transformer backwards in the u and v inputs. What’s the worse that can happen?

 

[Smouser]

I would try a 240 110 transformer backwards in the u and v inputs. What’s the worse that can happen?

I agree, I think Pete also suggested it.

I have been looking at FB marketplace but nothing has come up locally so far.

There are a few 3KVA transformers near me but I will probably need a 5KVA unit.

 

[knighty]

any other transformers laying around?

just to power the VDF up and check for errors... not to run your motor

 

[minimutly]

any other transformers laying around?

just to power the VDF up and check for errors... not to run your motor

Yes, you don’t need a big one to prove the concept and run the motor no-load.

 

[Smouser]

No random transformers unfortunately

My local mate has got a 1.6kva 110 transformer but I don't think he will be too happy if I start messing with it.

I will keep looking for a transformer locally or travel a little further on the weekend if I spot anything.

 

[Hopefuldave]

IF (big if) the VFD has two banks of reservoir capacitors (fairly common, as >500v electrolytics are bulky and pricey - a 400v-class VFD will have 700vDC or so across the capacitors... Yes, they're dangerous, leave for an hour for voltages to bleed off before sticking anything in there) there's a fairly simple hack* that might work - does for me on an older ABB ACS-300-4P-9, meant for 380-480v 3 phase in, now running OK on 240 single-phase and driving a humunguous Brooke-Crompton 3-speed 3HP 415v-only motor the size of a dustbin (but beautifully balanced).

Example ACS355 main drive (not control) PCBs - note big black capacitors and orientation of negative white stripes on them showing they appear to be connected as two banks, negative to positive in the middle... if flipped over it'll be obvious whether they are.

Can cost as much as 20p if you have to buy the bits...

It does require a bit of electrical / electrronics nous, but IF (that big if again) the two banks of capacitors are in series - the + of one connects to the - of the other through a nice big area of copper PCB. Carefully drill a 4 - 5mm hole through the copper and PCB (being sure to avoid anything the other side, including other copper tracks), put a BRASS bolt through the hole with BRASS nuts, Solder to the copper then bolt a Suitable Terminal (Lucar male blade is good) on the free end of the bolt. Take the incoming Neutral to the terminal, Live to two (your choice) of UVW in (bring Live to one, put a jumper link to the other)- may need to move them around if it has phase loss sensing (doubt it, as you've not got a phase loss alarm so far). Using two of UVW in gives the 3-phase rectifier an easier time, as input current's going to be higher than on 3-phase.

It works by "voltage doubling" - the positive peaks of incoming mains will charge the + terminal of one bank relative to Neutral, the negative peaks charge the - terminal of the other bank, fooling it into thinking it's running on 480v. The capacitors' life will be shortened a bit as the charging current ripple will be peakier than on 3-phase, but by the time it's approaching a problem it'll throw up undervoltage alarms under heavy load so you'll know when to change 'em! ABB do it Properly, so there will be input surge-limiting resistors between the rectifier and capacitors that are shorted by a relay once the bus voltage is up (the loud click 3 - 5 sec after applying power) which helps the capacitors a bit.

You WILL need to wire the motor to 415v-star, as you'll want to go high-voltage with lower current rather than low-volts high current (derating the VFD output current - e..g. mine is rated 9A continuous out, motor is max 6A at full load) - but as long as you keep the max current below 10A to the motor you should be OK - if you leave it in Delta you'll need to set the output voltage limit to 240v to avoid letting magic smoke out of the motor at low frequencies!

Dave H. (there other one)

* Invalidates any warranty, UL approvals etc. and probably causes Gerbil Warming for all I know...

 

[Shox Dr]

Not read the whole thread, so might have been suggested earlier.

Have you tried changing the 240v input supply around. I have a VFD and it states not to use L3

 

[Hopefuldave]

Not read the whole thread, so might have been suggested earlier.

Have you tried changing the 240v input supply around. I have a VFD and it states not to use L3

Smouser saw a "A5031 - Drive is not ready for operation, eg, due to low DC voltage. Check input power supply" becaue it's expecting 380-480v and he's feeding it 240 - poor thing's famished!

Dave H. (the other one)

 

[Smouser]

IF (big if) the VFD has two banks of reservoir capacitors (fairly common, as >500v electrolytics are bulky and pricey - a 400v-class VFD will have 700vDC or so across the capacitors... Yes, they're dangerous, leave for an hour for voltages to bleed off before sticking anything in there) there's a fairly simple hack* that might work - does for me on an older ABB ACS-300-4P-9, meant for 380-480v 3 phase in, now running OK on 240 single-phase and driving a humunguous Brooke-Crompton 3-speed 3HP 415v-only motor the size of a dustbin (but beautifully balanced).

Example ACS355 main drive (not control) PCBs - note big black capacitors and orientation of negative white stripes on them showing they appear to be connected as two banks, negative to positive in the middle... if flipped over it'll be obvious whether they are.

View attachment 375408
Can cost as much as 20p if you have to buy the bits...

It does require a bit of electrical / electrronics nous, but IF (that big if again) the two banks of capacitors are in series - the + of one connects to the - of the other through a nice big area of copper PCB. Carefully drill a 4 - 5mm hole through the copper and PCB (being sure to avoid anything the other side, including other copper tracks), put a BRASS bolt through the hole with BRASS nuts, Solder to the copper then bolt a Suitable Terminal (Lucar male blade is good) on the free end of the bolt. Take the incoming Neutral to the terminal, Live to two (your choice) of UVW in (bring Live to one, put a jumper link to the other)- may need to move them around if it has phase loss sensing (doubt it, as you've not got a phase loss alarm so far). Using two of UVW in gives the 3-phase rectifier an easier time, as input current's going to be higher than on 3-phase.

It works by "voltage doubling" - the positive peaks of incoming mains will charge the + terminal of one bank relative to Neutral, the negative peaks charge the - terminal of the other bank, fooling it into thinking it's running on 480v. The capacitors' life will be shortened a bit as the charging current ripple will be peakier than on 3-phase, but by the time it's approaching a problem it'll throw up undervoltage alarms under heavy load so you'll know when to change 'em! ABB do it Properly, so there will be input surge-limiting resistors between the rectifier and capacitors that are shorted by a relay once the bus voltage is up (the loud click 3 - 5 sec after applying power) which helps the capacitors a bit.

You WILL need to wire the motor to 415v-star, as you'll want to go high-voltage with lower current rather than low-volts high current (derating the VFD output current - e..g. mine is rated 9A continuous out, motor is max 6A at full load) - but as long as you keep the max current below 10A to the motor you should be OK - if you leave it in Delta you'll need to set the output voltage limit to 240v to avoid letting magic smoke out of the motor at low frequencies!

Dave H. (there other one)

* Invalidates any warranty, UL approvals etc. and probably causes Gerbil Warming for all I know...

Great info!

Hopefully I get a chance to open the bad boy up tomorrow to have a look!

Thank you for the detailed post.

(FB marketplace has still not delivered a transformer either - messaged three people in Southampton today but none replied )

 

[Smouser]

Just a small update on the 'progress' I made.
I opened the VFD up somewhere around Christmas time but I could not properly get access to the capacitors without de-soldering some things (which I did not do due to a lack of time).

I then tried @Pete.'s suggestion of reverse wiring a 110v site transformer which did not work for me. The MCB immediately tripped when I tried to power the site transformer.
Once I get a bit more time, I will explore both options again and post a few further photos for advice.