Converting 480 to 240

Hello again,
Does anyone know if it's possible or worthwhile converting a single phase 480v to 3 phase 415v rotary converter to work on 1 phase 240 v to 3 phase 415 v ?

Mr muddle said:

Hello again,
Does anyone know if it's possible or worthwhile converting a single phase 480v ...

Click to expand...

Where did you find this alternating current unicorn ?

If the 480v single phase transformer has a centre tap, you could disconnect it and join the two 240v coils in parallel, remembering they have to be connected in phase with each other.

Jim

Jim, if I can upload pics of the inverter would you be able to advise if it's possible to change to 240v ?
Thanks.

If you can post some pictures of manufactures rating plate, and take cover off converter and some pictures of it's transformer and transformer's connections.
I would be surprised if the manufacture of this phase converter did not use a transformer that would also connect for 240v input.
And, if you can run this on 240v the rest of this RPC will work as it should.

Jim

In Australia the supply voltage is 240v Single phase, 415v 3 phase and that is available to everyone in the Cities, and most regional towns, but where people live in the rural or distanced from others they have to have their own pole type transformer.
Usually, 11kv to 240v but if they wanted they could have a 11kv to 480v that would be centre tapped. These are very very rarely used today, but on say a sheep station and your sheering shed was a great distance away, to operate a 480v single phase motor you would get far less voltage drop and would only need half the guage in copper wire.
And, also running electric welders. These electric motors have two 240v windings, so series connection for 480v and parallel connection for 240v. I should also say that by our Electrical Standards (AS/NZ 3000) the voltage was changed a while back to 230v/400v but other than apprentices having to do all their calculations to 230v/400v nothing else changed.
Obviously a neutral now has to be run to the Main switch board from the centretap and to any sub or final circuit.

Jim

Hi Jim, hope this is of use?

By the pictures you posted this may run from 240v but I would need better pictures, closer, larger and different angles so I can see what is there on that transformer. There looks like a manufacturers plate you could photo, is there a skewmatic attached inside the enclosure anywhere, does this RPC have a brand name and model anywhere, do you know for certain that this RPC was operating on 480v with the present wiring the last time it was used. I would like to be able to read all 12 numbers on that terminal strip and see all those transformer connections.

Jim

more pics

Hope this helps?
Have had an electrician to take a look but says it can't be done, but I suspect he is not up to it or not interested or probably both!

You are going to need to get close up pics.

#1 essential picture.... In your third pic, the long white connection block by the transformer, there are numbers hidden by the wires. You need a pic from an angle that clearly shows all the numbers on that plate.

#2 essential picture... In that same pic, there is a black and silver plate at the lower right side. The plate reads "Sturdy Electronics", and you need a close up picture that clearly shows all the stamped information on that plate.

#3 Essential picture.... The motor will have a plate on it that is similar to the one on the box, which will show voltages etc on it. You need a close up pic of that which clearly shows all the information stamped on that plate.

Any other pics may be helpful, especially if there are any more rating plates anywhere on the unit. If there are, close up pics that show all the information on them are needed. Plus explain where they are, if that is not obvious.

JST said:

You are going to need to get close up pics.

#1 essential picture.... In your third pic, the long white connection block by the transformer, there are numbers hidden by the wires. You need a pic from an angle that clearly shows all the numbers on that plate.

#2 essential picture... In that same pic, there is a black and silver plate at the lower right side. The plate reads "Sturdy Electronics", and you need a close up picture that clearly shows all the stamped information on that plate.

#3 Essential picture.... The motor will have a plate on it that is similar to the one on the box, which will show voltages etc on it. You need a close up pic of that which clearly shows all the information stamped on that plate.

Any other pics may be helpful, especially if there are any more rating plates anywhere on the unit. If there are, close up pics that show all the information on them are needed. Plus explain where they are, if that is not obvious.

Click to expand...

Hope these may tell you a bit more?