Thread: 230V motor on 240V ?

US machines rated at 220V are 3 phase. They will not work directly on our system. The US single phase voltage is 110V. Also will not work on our supply.

Originally Posted by NCArcher

US machines rated at 220V are 3 phase. They will not work directly on our system. The US single phase voltage is 110V. Also will not work on our supply.

My understanding of the US system is that they reticulate in 3 phase as we do. However when they step down to 110V (or 115V) for domestic consumption they do so with a centre tapped transformer winding giving 110V - 0 - 110V with the centre tap being the system neutral. General domestic consumption is drawn from either 110V to Neutral, but for high demand loads, it is possible to connect between the out of phase actives ignoring the Neutral. This gives 220V to supply the load. For dual voltage motors, the motors generally have pairs of windings, internally connected in parallel for 110V or series for 220V.

In theory, a dual voltage motor can be run on our local mains if configured for 220/230V. In practice, you have no warranty support, and nonapproved switchgear and cabling.

The other aspect to consider is that the motors would be predominantly induction motors with cenrifugal switches and start capacitors. The speed of these motors is determined by the mains frequency and you take a 16% speed hit because we have a 50Hz mains where they have a 60Hz mains. Could potentially be overcome by changing pulleys on belt drive units, but the motors then have to work harder and have less cooling airflow.

Should have remembered...yes, line1 and line 2 gives 220/230.
So basically its a matter of getting a new motor. Not a big deal for a pulley driven. In fact I could probably buy without a motor to save on fright.
Alternatively get the motor rewinded for 240V single phase

Anyone has ever done this?

Originally Posted by Marc

Should have remembered...yes, line1 and line 2 gives 220/230.
So basically its a matter of getting a new motor. Not a big deal for a pulley driven. In fact I could probably buy without a motor to save on fright.
Alternatively get the motor rewinded for 240V single phase

Anyone has ever done this?

I've done a bit of rewinding in my time. But going back a step - the problem with the frequency is not only the speed the motor rotates at, but the amount of current the motor draws. There's no gaurantee that the rewinding will work. In the old days it might have, since motors were built a fair bit heftier than they are today. These days, the amount of metal inside the motor is reduced to the minimum and this means it'll be easy to overheat and burn out the motor.

Even if the frequency was the same, using a 230V motor on 240V will cause overheating, 220V is even worse. The supply authorities in Australia have different regulations in regards to limiting the voltage at your premises and this is typically minus 10% plus 6% of their agreed supply voltage (WA used to be 250V I think?) meaning your electrical pressure could be as high as 254V. 34V over the rated voltage is not going to be good for your windings.

Replacement would be the best option. But you'd have to consider what effect the reduced motor speed would have on performance of your machine. Maybe none if you could change pulleys.

Originally Posted by Marc

Hi there!
I am after a technical answer if possible

Does anyone know if there is a problem importing machines from the US wired for 230V and plug them in our 240V?

I have a Festo sander that is rated 220V and have used it extensively for years without any problems, however I was thinking in importing some bigger machines from either Jet or Delta. Has anyone done this and used without modifications?

Hey Marc,
to me, this seems like a very costly way to buy a machine. As I understand it, Jet machines are made in Tawain or China, then exported to the USA. From there, they are sent to where ever the customer is. Bit like sending something from Brissy to Sydney via Perth. IMO, this is one reason the Jet is more expensive than a lot of other machines. Not saying they are not good machines.

Have you had a look at Leda Machines. I can't go past them myself.

JMO.


Steve