3 phase inverter advice

[SimonH2]

It seems you will need to carefully examine the wiring in the machine.

The site Google comes up with for Transwave seems to be permanently down. But I found this page on eBay and note that it says :

D.C. braking circuits (rectifier circuits) and lighting circuits (control transformers)
There is more room for error connecting these circuits to a converter output than would be experienced on a mains three-phase supply. Two specific phases must be connected to these circuits, both on rotary and static converters. ...

which does tend to confirm my suspicions that they'll be auto-trnasforming the 240V to 415 to get 2 of the phases.
You also need to check that the machine only needs a 3-wire supply (no neutral) - if it needs a 4 wire supply (3P+N) then you'll need to do some re-wiring or other alterations.

As for the two speed motor, where's the jealousy emoticon on here !


EDIT: I find it slightly concerning that the company site has disappeared, and that page on eBay (which I assume is theirs) has no photos.

 

[fuzzytrifle]

It seems you will need to carefully examine the wiring in the machine.

The site Google comes up with for Transwave seems to be permanently down. But I found this page on eBay and note that it says :

D.C. braking circuits (rectifier circuits) and lighting circuits (control transformers)
There is more room for error connecting these circuits to a converter output than would be experienced on a mains three-phase supply. Two specific phases must be connected to these circuits, both on rotary and static converters. ...

which does tend to confirm my suspicions that they'll be auto-trnasforming the 240V to 415 to get 2 of the phases.
You also need to check that the machine only needs a 3-wire supply (no neutral) - if it needs a 4 wire supply (3P+N) then you'll need to do some re-wiring or other alterations.

I went over to my brother's yesterday to help fit a shelf for the converter and see the lathe up and running. Finally found out which model it is:

http://www.ebay.co.uk/itm/TRANSWAVE...ial_Automation_Control_ET&hash=item257f16ede0

It can cope with with a maximum motor rating (either single or combined) of 2.2kW. The lathe itself has been fitted with a 16A C type breaker, but no isolating switch as it's just plugged in. I checked the work lamp wiring and it is connected to one of the phases and the neutral and has been working all week.

I didn't get a chance to look inside the converter and I don't think I'd understand what I was looking at if I did, but it has a 5 pin socket - 3 phases, neutral and earth - which is what the lathe requires. Everything seems to working fine - as he illustrated by taking a 3mm cut off a 1" mild steel bar as if it was a piece of plastic - which was more than impressive for such a compact machine.

Apparently Transwave only have an ebay presence and aren't very helpful over the phone, but as everything's been running perfectly for the past week my brother doesn't have any concerns with the set-up.

 

[ericmark]

Interesting your Ebay advert says "TRANSWAVE Rotary Converter" but elsewhere here for example they are described as "TRANSWAVE Converters - Static Converters" the rotary type picture clearly has a motor behind the control box.

You say all is working A1 so no worries but as to protection which was your first question I would guess there is no RCD protection through the device. So even if there is a RCD on supply it will likely not detect any faults after the inverter.

I do not personally see this as a problem.

As to quality it's all down to the capacitors used. Be it a simple laptop supply or a large supply like you are using the capacitors will in fullness of time fail. But one would hope you get many years of use first. However I would always switch off when not in use.

 

[SimonH2]

Interesting your Ebay advert says "TRANSWAVE Rotary Converter" but elsewhere here for example they are described as "TRANSWAVE Converters - Static Converters" the rotary type picture clearly has a motor behind the control box.

The picture with the motor behind it seems to be for a much larger unit - up to 22kW.

The one you link to is like the one we have in the garage - and is a static converter. Inside it has an autotransformer which creates 415V across two wires, plus a capacitor bank to make the third phase. The lower switch on the panel selects the amount of capacitor to suit the load, plus it has a voltage sensitive switch that applies more caps while an attached motor is starting and dragging down the 3rd phase.

The OPs, unit doesn't have that second switch, only the on-off switch, so I guess it has a small "rotary transformer" inside - whether it's a standard motor or specially wound for the application would be interesting to know.