Good prices on VFD

[Tony]

http://www.ebay.co.uk/itm/300870658077
http://www.ebay.co.uk/itm/300870661661
http://www.ebay.co.uk/itm/300870665491

The first one (lowest powered) I've offered him £20 for - Mark gave me a little 112W three phase gear pump that it would drive just fine.  I know the motor works because I hooked up a cap to the third phase and it ran ok a while back.  So I'm thinking variable speed drywash pump.

The others are equally very well priced, if anyone wants to drive a three phase motor at variable speed.

[photoman290]

i am sure they exist but i dont think 3 phase 240 motors are that common. except in the states. never seen one anyway. of course you could  a 3 phase transformer and use a 415 volt motor which are common. wonder if you can just use one phase and a single phase motor?

[therecklessengineer]

3 phase motors can be wired in star/delta for 230/415V operation.

I run a 3 phase pump on my processor using a VFD. Works very well.

[Rotary-Motion]

dont understand this bit?

This drive can be used topower a 230V three phase motor from a 230V supplymaking it possible to run three phase machines from astandard single phase supply.

i always thought you can run 240v motors on 240v supplys just useing a 3 pin plug basically, well i do on my yaqm105...

and tony hehe you tryiing to buy off auction and trying to get him to end early?  floating ebay laws and rules... 

[Tony]

dont understand this bit?

This drive can be used topower a 230V three phase motor from a 230V supplymaking it possible to run three phase machines from astandard single phase supply.

i always thought you can run 240v motors on 240v supplys just useing a 3 pin plug basically, well i do on my yaqm105...

240V single phase motors have a small start winding to kick them off in the right direction and usually a run cap to energise this winding.  You can make a three phase motor run off single phase but you need to give the third phase a cap in a similar way to "nudge" it in the right direction.  Or, a rope around the shaft to get it going the right way

But a cap is not an efficient way to run a three phase motor, and it'll be down on the rated power (2/3 power I think?)

As James says so long as you can connect the three phase motor windings in delta formation then it'll run three phase 230V.

and tony hehe you tryiing to buy off auction and trying to get him to end early?  floating ebay laws and rules... 

Don't ask, don't get

[therecklessengineer]

dont understand this bit?

This drive can be used topower a 230V three phase motor from a 230V supplymaking it possible to run three phase machines from astandard single phase supply.

i always thought you can run 240v motors on 240v supplys just useing a 3 pin plug basically, well i do on my yaqm105...

and tony hehe you tryiing to buy off auction and trying to get him to end early?  floating ebay laws and rules... 

Yes, a 240V single phase motor will run on a 240V single phase supply. A 3-phase motor can be connected in differing configurations for 415/230V operation - but must be 3 phases, even with 230V operation.

There are various ways of 'bodging' a three phase supply from a single phase source - like adding a capacitor, or even using another large 3 phase motor to 'generate' three phases from it's rotation.

Given the cost of VFDs these days, it's really not worth it - especially given the amount of control and protection they give you for your motor. Mine will trip out on overload/overheat/phase loss/earth fault etc etc.

[Tony]

and tony hehe you tryiing to buy off auction and trying to get him to end early?  floating ebay laws and rules... 

He relisted it for me at £20 as a private auction, so now I have a nice little VFD on the way to drive Mark's gear pump

I'm going to plumb it permanently into my settle tank with three output valves, one to pump back into the settle tank (as a gentle agitator during settling) one via the drywash tower (circulate through drywash tower) and one to discharge into final storage.

Might add an additional two valves at the bottom with a spigot so I can suck biodiesel into the settle tank or drywash a batch that isn't in the settle tank.

Happy tinker time will ensue

[1958steveflying]

and tony hehe you tryiing to buy off auction and trying to get him to end early?  floating ebay laws and rules... 

He relisted it for me at £20 as a private auction, so now I have a nice little VFD on the way to drive Mark's gear pump

I'm going to plumb it permanently into my settle tank with three output valves, one to pump back into the settle tank (as a gentle agitator during settling) one via the drywash tower (circulate through drywash tower) and one to discharge into final storage.

Might add an additional two valves at the bottom with a spigot so I can suck biodiesel into the settle tank or drywash a batch that isn't in the settle tank.

Happy tinker time will ensue

That will be handy to have a variable speed gear pump.