2 post ramp 240v to 415v

[cuff4]

Hi Everyone, 

I'm after some advice on converting a 2 post 3 phase ramp to run off a single phase power supply. I've had an electrician come out and he said to my father-in-law that it's not possible (he drew the attached diagram for him). I was under the impression that I would be able to use a VFD.

Any advice on best options is much appreciated. The electrician said the motor can be 240 or 415v 3 phase.

Thank you,

Pete

[pauly22]

I’m sure you can buy a converter but they are expensive.

Could you not replace the motor with a single phase one?

[carat 3.6]

On that lift it isnt possible. you would need a hugely powerful converter to drive it, which along with all the other upgrades needed to make it work just isnt worth it.

Either run a 3 phase supply to it, or buy a different lift.

[ahebron]

I cant see why VFD couldnt be used as it looks to be a belt drive screw hoist.
If buying from say Aliexpress then I would get 3 x the motor rating.

[welshpug]

Loads of those vfd's specifically state not for use with vehicle hoists.

www.machinemart.co.uk/p/14801-power-transwave-mt15-15kw2hp-rotary-p/


This one doesnt, though may not be large enough to drive the motor, you havent said what size it is.

Probably cost more than your used ramp...

[slater]

He might mean the motor is wired star permanently. Quite common on older motors. VFDs need it wired delta. Need to see the motor cover removed to tell.

Direct drive lifts arnt the best for converting to 240v as the motor is so big the correct vfd would be expensive and draw a lot of single phase current. Would probably require dedicated feed from the consumer unit at least.

[cuff4]

[cuff4]

Thank you all for the info.

Could I wire 240v delta and use a 240v output vfd (like in the YouTube video) or is the only option to either get rid of it or change the motor?



Thank you,

Pete

[brachunky]

Mar 5, 2024 12:19:53 GMT cuff4 said:

Thank you all for the info.

Could I wire 240v delta and use a 240v output vfd (like in the YouTube video) or is the only option to either get rid of it or change the motor?



Thank you,

Pete

I have just installed this exact VFD (4KW) on a 4 poster fitted with a 1.5kw motor. (being a Chinese unit, I wanted to over spec the VFD just in case!) You will need to change the motor configuration to delta in order for it to work correctly. I can't make out for sure from your photos but if that motor is a 3hp, you may struggle to find an affordable VFD to work with it.
Then of course, it would be best connected to the DB board via it's own breaker with the cable rated at around 4x the motors amperage. Here lies a problem that the Chinese VFD's don't have lugs large enough to accept the larger cables. I used 4mm cable and that was a tight fit but managed it.

[madwrx]

that control transformer is 415v to 24volt ,that will need changing too if your changing the motor voltage as the t/former is 415 only ,,,the car park electric gate industry uses lots of 240volt to 3 phase converters ,,sometimes you just have to accept their isnt a good cheap option ,,,all easy to sort ,,,an inverter will be cheaper than a lift of that size in 240volt,,,trhe start current is controlled by the inverter so the big rise in current that would be seen with direct on line starting wont apply ,,,just wire it in 2,5mm ,,,if you buy the chinese unit buy more than one and fit a decent overload to protect the motor and inverter ,,the chinese units are average at best in my experience

[madwrx]

i just looked on alibaba at some of the VFD available ,,,if your buying be aware that many units will be 240 3PHASE inlet designed for the american/south american markets where their 3 phase is 240 volt ,,make sure you look for a 240volt single phase inlet ,with that motor you can have either a 3 phase 240volt or 400 volt oulet from the vfd ,,,witha vfd you can probably just use some external buttons to go up and down,,,assuming their arnent other safeties in the system ,,then you will need a 240/24ac transformer to integrate into the safety switches and cut out the vfd internal stop circuit ,,via a no volt connected relay

[carat 3.6]

Mar 5, 2024 12:19:53 GMT cuff4 said:

Thank you all for the info.

Could I wire 240v delta and use a 240v output vfd (like in the YouTube video) or is the only option to either get rid of it or change the motor?



Thank you,

Pete

I assume that a 3 phase supply is not possible? That would be the best option, most incoming supplies are 3 phase it's just a matter of how it's divided up in the board.

[madwrx]

the inverter can take a single phase supply and output a 3 phase supply ,,,only commercial buildings will have 3 phase supplies,,assuming your at home you will need to either change motor to a single phase unit or find a single phase to 3 phase converter ,,,as i said i see them on commercial gate controllers,,these are often only 1,1kw rated units though,,,where have you installed this lift Pete

[madwrx]

www.electrotechdrives.co.uk/product/singlephaseelectric-motor-2-2kw-3hp-1400rpm/


they make 230 volt versions of this motor