Transwave converters

recipio

Gents,
I'd like to get a powerful bandsaw and that means 3 phase. (I'm thinking of the Hammer N4400 which has a 4hp three phase motor.) I'm looking at a converter rather than mains 3 phase as I'll probably be moving in a few years.
The internet is full of info and nothing seems straightforward.
I'd like to run one machine only. Has anybody got any experience of doing this ?

cheers.

Double Barrel

recipio

No experience with the Transwave Co.- but I do have a rotary converter that supplies the power to a Meber 800 bandsaw. http://www.meber.com/

As you probably are aware - Three phase (3ph) power is a type of polyphase power transmission used on most power grids since it is more economical to move the energy and also uses smaller conductors.
3PH gives the motor 3 impulses per revolution. Single phase gives only one. The difference in the quality of power is very evident with 3 phase motors. But,you must use rotary phase convertors or digital €£$ converters rather than static converters to get true 3 phase, in other words - true power to the motor equates to full H.P. rating of the motor. Static converters deliver only about 3/4- 75% (or so) of the true power of the motor.

It involves the "hot" conductors which carry alternating currents at the same frequency but with their waves offset so the peaks arrive at different times each offset from the other two by a third or two thirds of a wave. This results in a smooth energy delivery versus single phase. 3ph power does not need a neutral since the load is connected between phases. The other major benefits are the simpler motor design and it also reduces motor vibration due to the linear nature of the delivery into a balanced load. Three phase is chosen since it is the lowest phase order which accomplishes the above goals.

The fact that producing 3ph from single phase has become more widespread, cheaper and the quality of the "power" has become better results in hobbyists or small shops without commercial 3ph power being able to reasonably buy and use large (or small) 3ph machines that have historically gone for literally pennies on the Euro/Punt. I have purchased used/old commercial/industrial equipment with many, many lifetimes of use left in it - for 5-10% of what it would cost to buy a new one.

Give Seamus Forristal, a ring he installs rotary convertors and is situated in New Ross, Co Wexford:http://www.sfphaseconverters.com/index.htm

Double Barrel

Cruising the internets.:D

This company has a fairly compensative explanation of converters on their website:

"For small 3 phase machines and in cases where you only have one 3 phase
machine and especially if that machine is fitted with the DUAL VOLTAGE motor then
fitting an inverter will be the cheapest way to get your machine up and running, basic
inverters are only small units and they need to be wired into your machine BUT once
fitted you then have in effect a SINGLE PHASE machine and if you ever resell it you
will be able to get a much better price for it as a single phase machine than you
could hope for in its 3 phase format,

You will find that 90% of the motors out there that are under 5 HP and were made in
the last 30 years will be fitted with DUAL VOLTAGE motors, basically a dual voltage
motor is one where you can select the voltage it runs from simply by exchanging the
links in the motors terminal box, this connection is called STAR and DELTA mode, in
STAR mode the motors running voltage will be 415V where as in DELTA mode it will
be 220V, for the manufacturer of the machine having a dual voltage motor is an
advantage if they ever export the machine as in some countries their 3 phase
voltage is 220V so if they had a drill for example and wanted to sell it in the USA
then simply by changing the links in the motor to DELTA and replacing the coil in the
starter switch box from a 415V coil to a 220V coil the machine would run just as well
on American 220V three phase as it would here in the UK on 415V three phase, this
is also an advantage for you if you want to run the machine here in the UK, this is
because if you were to swap the links over to DELTA mode you would then be able
to run your motor from single phase simply by using a BASIC 240V INVERTER, for
the 240V inverter this is an easy task as all the inverter has to do is take your 220V
single phase input and change it to 3 phase, the voltage is not changed and as its a
comparatively low voltage this range of inverters are not at all expensive and they
are physically very small, in fact for motors up to 5HP you can hold them in than
palm of your hand at arms length !,

Continue reading: http://www.drivesdirect.co.uk/how_to_choose.htm

recipio

Thanks Double Barrel, that's valuable info.
I'm not stuck on using Transwave, its just that I see them at every UK show I go to and they seem to have a large slice of the market.
I'll follow up on the links and I appreciate the info.