I had an Altivar 8 inverter ‘converting’ 240V single phase into 240V three phase. It drove the 3 ph motor on my lathe via the lathe’s forward-off-reverse switch and then the lathe’s low speed-off-high speed switch. It was old and not really man enough for the job, but it worked. Until just over a week ago when it announced it had had enough, and died. The inverter was powered up to 50Hz by closing a switch on a logic input.

 

I replaced it with an Altivar 28 inverter, which is man enough for the job but with far more control options, which I don’t need. All I need is for it to give me 3 ph 240V at 50Hz. End of! It seems fine, giving the option again of a 2 wire logic input across which I have the same switch as before.

 

The 28 has 50Hz and 2 wire control as factory default settings, and I have set it to ‘auto-reset’ (I think!) after a stop.

 

But it won’t go. It only goes to a ‘ready’ state but will not power up to 50Hz.

 

Can anyone help in pointing me in the right direction here? There seems masses for configuration options which I surely don’t need, but there must be one somewhere which I do need. Help!

 

Chris

Hello, and thanks to all that have responded.

 

I have now managed to get this going, after obtaining some advice from Direct Industrial who also do reconditioned inverters at a good price and with a ‘comprehensive 12 months warranty’. Needless to say, I have no other attachment to this company other than the advice they gave me!

 

Anyway, firstly, I had to reset the low speed setting on the inverter to 50Hz from the factory default of 0Hz – I in my naivety had assumed that because the machine had been set to being a 50Hz machine then that would be that. Then I found that it still would not start up if either of the 2 switches between it and the motor were in the ‘off’ position. Instead it would sense an ‘open phase fault’ situation on the motor and stop. However, this protection is offered with the option to be switched off in the programming if precisely this condition (of a switch between inverter and motor) exists, so, once that option had been taken it worked!

 

For those who inquired about the motor, the lathe is a German Weiler 280 from the mid-60’s, with a two speed reversing motor fitted as standard. There are 2 sets of windings; the low-off-high speed switch switches between these two windings. It has run in the past OK as said before; it was designed to do this!  I think in this instance when the inverter went phut I had an earth fault which caused the damage; in fact, I am certain I had because I subsequently found one found. All wiring has been now been throughly checked through again and is fine (he says with quite some hope!!) so hopefully that will be that. The lathe is a good one but has obviously had some use over the years; there is some wear in the bed but it is not so bad as to warrant a regrind. You just have to take account of it, but I have not had a problem so far with it. It has a range of speeds in high and low mode via a set of stepless adjustable pulley wheels and a 2 belt drive between motor and headstock, powered cross feed and longitudinal feed and screwcutting feed, and gear wheels to cut just about all metric and imperial threads and interestingly, for a German machine, has the cross feed and top slide graduations marked in ‘thous’.

 

Chris