220V single phase to 380V three phase

[JohnHaine]

Hard to say if it would stall at the lower speed, that's more a function of torque than power. Just change the pulley ratio surely? But you can vary the speed with the VFD of course.

Ideally you need 3 core screened cable. The current won't be particular high so anything rated at 5A per core would be fine I'd guess. There is debate about how to connect the screen but for RF the screen should be firmly grounded to the E terminal of the VFD at one end and to the motor casing at the other. If you can't get 3 core screened then electrical suppliers sell 4 core cable for 3 phase one of the cores being for a ground.

[m_c]

Personally I'd probably wire it for low speed, then overspeed it via the VFD.

You could wire it for highspeed then run it slower from the VFD, but you won't get as much torque at the lower speeds.
From the plate details
0.45KW at 2800rpm is 1.53Nm
0.3KW at 1400RPM is 2.05Nm

Using the high speed windings, you'll have 1.53Nm from 2800rpm down to probably a few hundred RPM. This depends on VFD ability, motor performance, but it'll reach a point where the motor will noticeably lose performance and likely become noticeably rough.

Using the low speed winding, you'll have 2.05Nm from low speed to 1400RPM. Due to the lower rated speed (the two speed essentially works by selecting 2 or 4 pole operation), the motor will also be capable of being spun slower before performance becomes an issue.
From 1400RPM to 2800RPM, the power output will remain limited at 0.3KW which means the torque will gradually reduce from 2.05Nm at 1400RPM down to 1.02Nm at 2800rpm.


However, if your main use was in the higher speed range, then wiring it for the higher speed range would make more sense to get the most power.
Off course, you could add a changeover switch, but you'd have to ensure you don't switch it with the motor powered and spinning.

[mekanik]

mc

Thanks for taking the time to reply and your power calculations.

I contacted motorsandinverters and quized them about the 380V on the motor plate and they said a 220V inverter drive would not work with the motor, they offered a static converter @ £1100+VAT and said that would do but from what i understand as static converter supplies 2 phases, and the proper way to do it is with a rotary converter. so back to square one.

If i took some readings of the original single phase motor would you be able to determin which of the coils is damaged, and if the low speed coils are OK i could disconnect the high speed coils from the switch.

The motor actually run OK it was just the fact that it was getting hot that made me investigate.

[JohnHaine]

Found this on Amazon
https://www.amazon.co.uk/Inverter-AT.../dp/B0892L6CZM

[mekanik]

Found this on Aliexpress
the video shows the chappy with a meter 220v input and outputting 410V so should be good to go, the feedback is good as well, downside being the month or so shipping plus my last purchase from Ali never arrived.would be nice to put this disaster to bed.
Kindest Regards
Mike
https://www.aliexpress.com/item/1005...d=CBSN0q3HLTrF

[mekanik]

John/MC
Hi Guys
Just an update on my lack of progress, ordered the VFD/screened cable/Fan/Potentiometer from Aliexpress.
When I had a look @ the manual for the VFD it stated that it required a 5K Potentiometer (I had ordered a 10K) so had to order a new one, tried to do something similar to Clough42 (James on YouTube) so sourced a breaker and fuse holder off e-bay. Had a problem trying to secure the secondhand 3 phase motor due to the strange mounting arrangement, but as luck would have it the motor end covers off the single phase motor actually fit the main body of the 3 phase motor so one job sorted. Not having much of a clue regarding the fuse requirements I got a couple of 10A and 20A Quick Blow fuses, pottered around making the cables up and eventually got round to connecting everything up to the high speed windings. Turned on the power and the fuse holder illuminated red then the fuse (10A) blew, tried another 10A same/same.
Installed a 20A this time the red light on the fuse was not illuminated wound up the potentiometer and the motor actually ran(now @ 50 Hz) the problem was that it didn’t seem to be running as fast as I thought it should, I assumed 50Hz per second should have produced 3000 RPM but I don’t think it’s anywhere near that, and I have no way to check it. Went into the menu and managed to increase the frequency to 200Hz and this did increase the RPM, tried to take it to 300Hz but didn’t run very well and would initially run up but then stalled. Had some problems trying to get it back to factory settings but the factory reset didn't work so could not drop the frequency back to 50Hz, after some time in the setup I managed to get it back to 50Hz, but I don’t know if the VFD is damage or the motor is just US.
Just by accident itouched the EMI filter body and got a shock, checked the voltage on the filter output and it was about 750V. disconnected the leads to the VFD and the output from the EMI filter was back to 240V. connected back up to the VFD and this time ther was an error code E5VC1. came back after a brew and this time it had an error code of E0C3.
Had a look today and the error code has cleared and managed to bget the motor running at low speed as before, so it's looking a bit sick.
Had a look online and seem to have found a motor that might be suitable.
https://www.ebay.co.uk/itm/114122298...40ba%7Ciid%3A1
There are 2 speed options 1500 and 3000 RPM.
I really only require the 1400 and 2800 of the original motor, what would be your opinion of the best motor to go for, will the 1500 motor be able to go upto 2800, i would be going for 0.75Kw so a bit more power that the original motor.

Regards
Mike

[JohnHaine]

Ask Inverter Drive Supermarket. They have a (rather poorly written) application note on 230v running. The people you spoke to want to sell you a static converter. They also have 230v 1-phase to 380v 3-phase units. "Static" converters are yesterday's technology. (Actually a VFD is "static" but generates proper 3-phase.)

[mekanik]

Thanks for that John
I had seen 230V to 380V three phase VFD's advertised, just as well i came in for brew i was about to swop the motor covers and rotors again and commence on a box to send the single phase motor for a very expensive rewind.
was on a forum yesterday and some guy in the US added a stepup transformer before the inverter then bought a 440V to 440V VFD apparently that worked and i have seen another US made inverter that does the conversion from 220V to 440v.
Will contact Inverter Drive Supermarket
Regards
Mike

[mekanik]

deleted

[m_c]

https://www.aliexpress.com/store/gro...000324416.html

It's worth going through the different listings, as I've see different delivery options amongst seemingly identical VFDs.

Other make to search for is Ecogoo.