Thread: Single Phase to three Phase converters

Originally Posted by brooklynboy

I have the opportunity to buy a second hand SCM Minimax CU350K, only trouble is its 3 phase and we are deep in the countryside, has anybody had any experience with phase converters?

3 Phase VFDs that convert single to 3 phase are only practical for motor up to about 4HP - any bigger than that and you will struggle to find a VFD that can do this.
Another thing is the motor should be able to be configured to run in "delta or ∆" wiring whereas the usual wiring is "star or Y" .
If it is not ∆ it may still run but it will not achieve full power.
Sometimes the name plate will show a ∆ or a Y on it.

If it is not a ∆ wound a motor rewind business may be able to convert it
OR
it may be cheaper to find a used 3 phase motor with that capability.
I have bought many used 3 phase motors over the years and they never cost me more than $50.
I scored a very nice 4 HP 3phase ∆ wired motor for $50 recently.

Cheers
Bob

Originally Posted by BobL

3 Phase VFDs that convert single to 3 phase are only practical for motor up to about 4HP - any bigger than that and you will struggle to find a VFD that can do this.
Another thing is the motor should be able to be configured to run in "delta or ∆" wiring whereas the usual wiring is "star or Y" .
If it is not ∆ it may still run but it will not achieve full power.
Sometimes the name plate will show a ∆ or a Y on it.

If it is not a ∆ wound a motor rewind business may be able to convert it
OR
it may be cheaper to find a used 3 phase motor with that capability.
I have bought many used 3 phase motors over the years and they never cost me more than $50.
I scored a very nice 4 HP 3phase ∆ wired motor for $50 recently.

Cheers
Bob

thanks for that info Bob, it all starts to look a bit to much of a hassle, and over here(NZ) a single to three phase converter costs about $3000 which I have to add to the final value of the machine.

You can often change the wiring on a 3 Phase motor from Y to ∆ in about five minutes - the windings are exactly the same, it's just how they connect to each other that changes, and is often configurable.

But the converters can be expensive, especially as the power rating goes up.

Could you install a single phase motor? I bought a table saw that had a 3 phase motor and have got on order a single phase to replace it. The motor will cost me around $300.

I did consider using a converter before I was told by Vector that the 3 phase plinth was right outside my property...

Get a 3 phase petrol generator just big enough to run the unit , then you have a back up power supply for your home in a blackout as well.