If the first Transwave was suspect you maybe should have contacted the manufacturer in Birmingham who, when I had an issue with one of their products, was extremely helpful and it was resolved. I can’t offer any ‘technical’ advice on the electrics because I am not qualified or knowledgeable enough but when I have a problem I try to apply logic and common sense. So, if the problem is common to both your new static and rotary converters I would suspect the motor as the common denominator. I am certain other more knowledgeable people on here will tell you how to check the windings properly but as a quick check I would just put an AVO across each coil just to make sure there is continuity and the readings across all three are pretty much the same, it might just provide a clue, or you could take it to a local rewinder for a proper diagnosis. Transwave statics are robust and reliable, IMO, I have used three of them for over 25 years with no real problems. Given that you have spent a considerable amount of money on a new static and a rotary converter I might consider changing the motor for a single phase and selling the converters to cover the cost.

By starter switch I’m assuming you mean a no volt release contactor type, is it the switch contacts that are burning out or the operating coil or overload? The more information you can give will make it easier for someone on here to help diagnose the fault remotely. As an initial check if you can get hold of a multimeter is as Chris says above continuity of the windings, that they are correctly connected in star for 415V , the contactor coil is the correct voltage rating, and all other connections in the whole machine are sound. When the motor runs does it run quietly and at an apparrenly normal speed? just thinking it could be two phasing. Sorry if this seems to have more questions than answers but it might help reach a diagnosis. Like Chris I’ve run machines on static converters for years with no problems, and yours should run perfectly on a rotary one. Perhaps if you have one in your area you could remove the motor and take it to a rewinders for checking out, good luck. Is your electrician conversant with motors and controls? agree with Dave above it does sound a bit poke and hope.

Dave

Might help if you put your approximate location you might find someone knowledgeable nearby.

“The transwave that came with it was looked at by a local company who said it wasn’t viable to repair and quoted £2500 to repair!!”

Some companies quote ludicrous prices because they simply don’t want the work, or don’t know what they are talking about, but won’t say so directly. Transwave statics are very simple devices, they simply place a capacitance across one winding of a three-phase motor and temporarily increase it to gain sufficient starting torque. I have configured a circuit like this myself on an ex-school Boxford shaper simply by following the information contained in the Workshop Practice book ‘Electric Motors’.

If you are in Lichfield you are not a million miles from Tyseley where Power Capacitors are based. They are the first port of call for all things Transwave. My understanding is that static and rotary converters are now old hat. The way to go is with an inverter with a 3-phase motor, but what do I know? It took me 3 hours to set up our new smart TV this afternoon!

That being said, if you have a little more confidence in your own judgement and common sense you will find that you know more than you ever thought you did, trust me!

DID it work on the transwave when you bought it ? DID YOUR ELECTRICIAN UNDERSTAND 3pHASE ? Is the motor wired star or Delta eg 240v or 415v Get an electrician to check the resistance of the 3 coils and put a insulation (megger ) tester on the motor. If that is sound and there is no excessive load be it bearings gone or the machine working to hard then The motor should be good. The whole point of the overload cuttout is to drop out at the right setting – in this case 1.65A Not 2.5A. wiring 240v ac to transwave, then the starter then the motor. IF it has laid about unused and got damp moisture could have taken out the windings ?. Will come back to this later ! Noel.

From what is described, it is drawing too much current and so frying the switchgear.  I would be checking that you have 3 phase power.  Given that you seem to have burnt out two converters, I would certainly be checking for continuity on all 3 phases of the motor, plus all the wiring.

Does it run a bit rough and have trouble starting?

Martin