Jim Kennedy
Aluminum
- Joined
- Mar 16, 2008
- Location
- Marulan N.S.W. Australia
I am posting this to give encouragement to those who are not sure if they could safely build, or how and where to get started on their own phase converter. I ask others who have built their own 415v converter, how did they do it.
I say Australia only because I know the secondhand market reasonably well.
I have built myself several phase converters of the Rotary and High Voltage Transformer types. I think the rotary type 415v is the better choice if it is for operating different motors, or machines with more than one 3phase motor, and if the machine has a 415v control circuit there is no further consideration, just plug it in.
If a converter is required that outputs 415v and inputs 240v, a transformer is needed.If you wanted to use a dry isolation (double wound)type secondhand (used) say 5kVA it would probably cost you more that $1000 if you could find one, then you would still need good advice for the Neutral Bonding arrangements for the secondary side of the transformer.
What I do, is to use old choke welding machines, because they are available and cheap on Ebay. The welder with least amount of work is something with input voltages (primary side of transformer)of 240v and 415v and then by simply re-arranging the links (jumpers) this primary winding becomes an Autotransformer which will input 240v and output 415v single phase.
Now this welder maybe advertised as being 3phase so check the affixed manufacturers specification plate and it will usually say Single Phase. In Australia a 3phase choke welder would be a rare thing and a very big industrial thing with multiple chokes usually associated in industry like ship yards. If the power supply cable is using two conductors and an Earth whether the two conductors are a Neutral and Active or both are Actives, that means Single Phase. A lot of people think if you plug into a 3phase socket outlet that the machine must require 3phase.
So now we have 415v single phase if it is connected to two of the terminals of a suitable 415v 3phase Idler motor and have a way of starting this Idler motor,(pony motor, button start with capacitors, button start voltage relay with capacitors, button start current relay with capacitors, rope around the shaft) we now have a working converter but you will probably want to do some balancing of the phases with the addition of run capacitors.
By using a welder as a Autotransformer some of the advantages are, very cheap if not free, they are very available, they have their own metal enclosure.
I would like to hear about other peoples success stories, maybe not quite there yet, maybe thinking would this thing safely work.
Jim
I say Australia only because I know the secondhand market reasonably well.
I have built myself several phase converters of the Rotary and High Voltage Transformer types. I think the rotary type 415v is the better choice if it is for operating different motors, or machines with more than one 3phase motor, and if the machine has a 415v control circuit there is no further consideration, just plug it in.
If a converter is required that outputs 415v and inputs 240v, a transformer is needed.If you wanted to use a dry isolation (double wound)type secondhand (used) say 5kVA it would probably cost you more that $1000 if you could find one, then you would still need good advice for the Neutral Bonding arrangements for the secondary side of the transformer.
What I do, is to use old choke welding machines, because they are available and cheap on Ebay. The welder with least amount of work is something with input voltages (primary side of transformer)of 240v and 415v and then by simply re-arranging the links (jumpers) this primary winding becomes an Autotransformer which will input 240v and output 415v single phase.
Now this welder maybe advertised as being 3phase so check the affixed manufacturers specification plate and it will usually say Single Phase. In Australia a 3phase choke welder would be a rare thing and a very big industrial thing with multiple chokes usually associated in industry like ship yards. If the power supply cable is using two conductors and an Earth whether the two conductors are a Neutral and Active or both are Actives, that means Single Phase. A lot of people think if you plug into a 3phase socket outlet that the machine must require 3phase.
So now we have 415v single phase if it is connected to two of the terminals of a suitable 415v 3phase Idler motor and have a way of starting this Idler motor,(pony motor, button start with capacitors, button start voltage relay with capacitors, button start current relay with capacitors, rope around the shaft) we now have a working converter but you will probably want to do some balancing of the phases with the addition of run capacitors.
By using a welder as a Autotransformer some of the advantages are, very cheap if not free, they are very available, they have their own metal enclosure.
I would like to hear about other peoples success stories, maybe not quite there yet, maybe thinking would this thing safely work.
Jim