I was given a converter are these any good

[Martin NewboldParticipant @martinnewbold]

Hi i have been given a converter and from what it seems it quite old but in good heart. Does anyone know anything about these , please?

[Martin NewboldParticipant @martinnewbold]

[Clive FosterParticipant @clivefoster55965]

Had 4 HP nominal one for some years. From the transformer I guess yours is also a 240 V in 440 V out (as voltages were then) device which is handy. I have a somewhat scruffy but intelligible PDF copy of the instruction sheet. PM me if its of use to you.

Worked OK but never really seemed to give a decent phase balance when used as a converter. Three position setting switch just gave a choice of buzzes. Perfectly functional but, having built a few in my time I'm a bit anal about such things. Eventually fitted a big pilot motor on the output, turning it into a rotary converter, which made a vast improvement. Still bit buzzy but fine provided you don't mount it, and the motor, on a shelf. Set the whole workshop buzzing when I tried that!

Ooops!

Important thing to remember when installed on a machine with proper, contactor, control gear is to ensure that all the control gubbins is powered off the incoming mains. If you try to use any of the generated legs there will be problems. Even when pilot motor is fitted to make it a rotary converter which theoretically should give you decent power on all three legs. Sometimes it does, sometimes it doesn't.

Fit a proper contractor on the input. Mine just had a monster toggle switch. Obviously factory.

Clive.

Edited By Clive Foster on 02/08/2017 18:14:36

Edited By Clive Foster on 02/08/2017 18:38:44

[Martin NewboldParticipant @martinnewbold]

This has a fused metal box switch on the front it runs up to 4hp through three switches .

 

Am clueless what the rod does in theright back as it rides up and down. Looksa lile a solenoid in black  I havent powered it up yet as was wondering what that bit was for.

 

Sure please send me a pdf as interested. My friend has a 7hp version which he has used in a big work shop without problems and it runs his machinary ok .So just wondered if this would do same?

 

Edited By Martin Newbold on 02/08/2017 18:23:26

[Martin NewboldParticipant @martinnewbold]

Have just connected it and powered it up and it makes a reasonable humming noise not connected to motor. Next step is to clean it up a bit

[Clive FosterParticipant @clivefoster55965]

Don't recall mine having that rod / solenoid thingy in the back. But it was a fair few years back and I never had to do any work inside. Just lifted the cover, made sure all the connections were tight, blew out the dust and put it to work.

Its probably the automatic cut out on the starting capacitor circuit. You need extra capacitance in the circuit to get the motor up and running. Once its up to speed the extra start capacitance has to be taken out of the circuit as it upsets the running phase balance. Some professionally built converters just had a manual spring loaded switch that you held down to, temporarily, bring the extra capacitance in. Alternatively there is a simple voltage sensing solenoid operated switch system that does the deed automatically when the generated legs come up to sufficient voltage. I used such on the phase converters I built. The instruction sheet implies that the MotoRun converters are so fitted.

If yours is like mine there will be a switch on the front with an extra start position, probably labeled "punch" which brings in even more capacitance to help get loaded motor running. Not something to use unless you have to as it really makes an unloaded motor jump!

PM me your E-mail address and I'll send the PDF along.

Clive

Edited By Clive Foster on 02/08/2017 18:56:20

Edited By Clive Foster on 02/08/2017 18:56:42

[Martin NewboldParticipant @martinnewbold]

HI Clive,

Yes this has Punch and Start on one toggle and three positions on the other toggles switch 2.5h to 4hp, 1/2 to 1hp and 1/2 to 2 1/2hp

I have tried to message you but your profiles is private.

[Martin NewboldParticipant @martinnewbold]

oh middle one was 1/2hp to 1hp lol You said i need to connect the wires in specific initial phase series I am connecting to 1, 3 & 4 on dewhurst

[Clive FosterParticipant @clivefoster55965]

Hi Martin

I'm envious. You got a proper mains switch with yours. I did have the snazzy engraved brass labels tho'. Rust flecked hammer blue paint too.

Sent you the PDF of the instruction sheet with a few extra notes and a re-type of the most relevant paragraph. Naturally that was the bit most obscured by the fold. I'll give it a try on the latest OCR program in the next day or two to see if a clean copy can be got. Version I had when i sold the converter couldn't cope.

Important thing is to make sure that the phase lines feeding the control gear contactors come straight off the transformer so there is power to the coils and switches when the converter is turned on. Should be Black and Brown wires. Third phase, Blue wire, doesn't appear until the motor is running.

Clive

Edited By Clive Foster on 03/08/2017 20:09:48

Edited By Clive Foster on 03/08/2017 20:10:16

Edited By Clive Foster on 03/08/2017 20:10:52

[Martin NewboldParticipant @martinnewbold]

This is a bit odd I think i need pdf . When i connect yellow and green to earth and any phases to Dewhurst switch 1 , 3,4 it blows my trip in the fuse box any ideas please have disconnected it all tonight for safety.

[Clive FosterParticipant @clivefoster55965]

Hi Martin

PDF should be in your gmail box. Probably not helpful with your problem tho' as it assumes that an electromagnetic contractor will be used to control the machine.

To me Dewhust switches are for controlling the direction motor goes in. Should only be operated with the power turned off. I know folk have used them successfully for power switching but have no experience in that area.

Stupid obvious question but are you sure that your Dewhurst is correctly configured for the three phase machine. Maybe 30 years back I had to re-jig one because it was incorrectly set-up for the machine. Properly mounted and nicely wired but clearly had never been used in anger. My mate got the machine cheap 'cos it wouldn't run, we expected to fit a new motor. Gawd knows what was actually wrong because, after so many years I certainly don't.

Clive.

[Martin NewboldParticipant @martinnewbold]

Thank you so much Clive, Yes the circuit diagram shows a 3 phase connection on the type A Dewhurst (**LINK**). I am guessing that I need to isolate the single and three phase earths and this is what is most likley causing the the fuse box to trip as when I unplug single phase equipment the converter runs fine and has a big clunk as it switches on

[Martin NewboldParticipant @martinnewbold]

Am waiting for my newest adventure in a motor to turn up . Have my fingers crossed with this one

[larry PhelanParticipant @larryphelan54019]

I have a Transwave rotary converter 10hp,runs everything in the shop. Got it mainly to run my 12" planer and spindle moulder [4hp motors on each ] No bother to it,although it is a bit of an overkill to run my lathe and miller [1.5 hp each ]There is a fair amount of noise from it,some due to the motor running and some from the box holding the transformer and other gear. I have it mounted on an angle iron stand,to save floor space,but the stand seems to act as a sound board ! However the point is it does work,and there is no messing around with switches or settings,just switch it on and forget it. Might try building an enclosure around it some time to kill the sound. Any idea,s anyone ?

[Andy CarruthersParticipant @andycarruthers33275]

Rubber "Barry" mounts between the convertor and frame?

[Martin NewboldParticipant @martinnewbold]

Mine is possibly more quiet as its on wooden floor. You could try a wooden shelf on top of your metal frame.

[larry PhelanParticipant @larryphelan54019]

Surprised that it,s quieter on a wooden floor,I would have thought it would be more noisy. I had half the frame fitted with a chipboard shelf and it seemed to act as a sounding board. The only reason I did not leave it on the floor was to use that space for other stuff. I will see about fitting rubber buffers to it,but I dont want it bouncing all over the place. If it fell off the shelf,it would make bits of itself,and me,if I was near enough ! I think most of the noise comes from the steel box holding the bits and pieces,because if I press my hands to the top of it,the vibrations reduce,and likewise the noise.

It,s not that bad but just something one could do without,the machines make enough noise themselves.

But having said all that,they do work,and that,s what matters because out in the sticks there is no way to get 3ph.

[Clive FosterParticipant @clivefoster55965]

An old tyre laid flat on the floor with a suitable board fixed to the top makes a pretty good poor boys vibration isolator. I imagine wheelbarrow size or similar would be about right for a converter. How effective it actually is depends how well the absorption of the tyre you happen to have matches the vibrations involved but, in my experience, it's always helped. Best if there is a reasonable weight on top. Maybe piece of redundant kitchen worktop for the board as its heavy as well as strong.

Converter on a shelf rarely seems to be good idea. My MotoRun set the whole shop going when I tried that. Very unpleasant and rapidly removed. Naturally muggins put the Bridgeport and other stuff in after hefting the converter into place before testing. So it all had to come out again few days later after being judged unacceptable to make room to safely pull the converter off the shelf. Grrrr!

I've used "stiff hinge" devices consisting of thick rubber hose, e.g. old style car heater hose, pushed into suitable tubes with nicely fitted pins through the middle as vibration isolators. I really wanted the no shake hinge bit but they did reduce transmitted noise. So maybe similar style shelf mounts could help.

Similar idea can be used for flat plate isolation. Drill suitable holes in thick ply wood, kitchen works or similar for the plate. Poke short lengths of thick rubber tube through the hole so there is enough ticking out for a nice mushroom shape squidge down. Hefty washer on top and bottom and snugly fitting through bolt or stud. Probably works best with two plates having aligned holes for the rubber tubes. One fixed down to or simply sitting on floor, shelf or whatever. The other having the thing to be isolated fixed to it. Thick washer between the rubber tubes as well as top and bottom. Tweak the bolt tightness to vary the squidge and tune the isolator.

Sorry not a clue about design rules. I've known it work pretty well. Big temptation is to overdo the squidge "so it doesn't fall out". Maybe some bits in the projecting rubber would help get the squidge – stiffness ration right.

My mate Mike the (ex)Pilot has the best answer. His workshop is a nicely insulated box in a an agricultural barn style shed, building in a building style. Transwave converter lives out in the barn on the other side of a 4" thick insulated chipboard on timber cavity wall. Noise, what noise.

Clive.

Edited By Clive Foster on 18/08/2017 13:12:40

[larry PhelanParticipant @larryphelan54019]

Hi Clive, Your mate Mike has the right idea,that,s the way I,m beginning to think too.

Like Mothers -in law,they are useful to have around but not to listen to for too long !

[Martin NewboldParticipant @martinnewbold]

Hi Larry . Its sitting on Marine ply on 4×2 frame under shed on concrete base.

You wrote "Surprised that it,s quieter on a wooden floor,I would have thought it would be more noisy. I had half the frame fitted with a chipboard shelf and it seemed to act as a sounding board. The only reason I did not leave it on the floor was to use that space for other stuff. I will see about fitting rubber buffers to it,but I dont want it bouncing all over the place. If it fell off the shelf,it would make bits of itself,and me,if I was near enough ! I think most of the noise comes from the steel box holding the bits and pieces,because if I press my hands to the top of it,the vibrations reduce,and likewise the noise.

It,s not that bad but just something one could do without,the machines make enough noise themselves."

But having said all that,they do work,and that,s what matters because out in the sticks there is no way to get 3ph."

Edited By Martin Newbold on 18/08/2017 17:07:44

[Martin NewboldParticipant @martinnewbold]

Hi All, I have got it running with the help of Mike Pool it reverses through Dewhurst coreectly and is looking good . I have to bolt it in and get a new pulley as bore of shaft is larger at 24mm. Curiously the Motorrun Phase converter occasionally trips the shed fuse instead of the house fuse which is unlike the VFD I had.

I have worked out this seems to be to do with the order it is switched on. I am happy the motor I have chosen is larger and more capable that the pathetic power motors I have been advised previously by suppliers to buy. Things are starting to come togethr finally to get it working.

Edited By Martin Newbold on 22/08/2017 09:54:05

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