MadModder
The Shop => Electronics & IC Programing => Topic started by: Bluechip on June 13, 2012, 03:26:57 PM
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Hi Troops
The static converter has gone pop on my Myford S7. It appears to have lost a phase. :zap: :scratch: :bang: during the arduous task of tapping a M4 thread in brass.
As the thing appears to date from Nov. 1991, I am not inclined to faff around with it too much.
The output is 415V, or rather was when it was alive. Now have phase to phase volts of 422V / 0V / 411V
[1] Anyone got a schematic of the damn thing ?? If it is just a shagged capacitor I might just give it the benefit of the doubt and refurtigrate it.
[2] Anyone fitted a Newton Tesla VFD to a S7, if so, why are there apparently 2 versions ? ie 1/2 HP & 1 HP ?
The Transwave one I have is 1/2 HP. I see no point in fitting a larger one, but is there a reason why more grunt would be an advantage ?
A much miffed ...
BC
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I would love to help you Dave........ :thumbup:
If I could understand what you are saying! :scratch:
Yours, in total electronical ignorance, :zap:
David D
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I would love to help you Dave........ :thumbup:
If I could understand what you are saying! :scratch:
Yours, in total electronical ignorance, :zap:
David D
Ah well ... these things are sent to try us ... anyway ...
Off to Belper Motor Spares tomorrow .. rattle can of 'Norwegian Blue' paint ... :lol:
BC
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I would love to help you Dave........ :thumbup:
If I could understand what you are saying! :scratch:
Yours, in total electronical ignorance, :zap:
David D
Ah well ... these things are sent to try us ... anyway ...
Off to Belper Motor Spares tomorrow .. rattle can of 'Norwegian Blue' paint ... :lol:
BC
Nice one Dave!
A new coat of paint is always a great improvement..... :D
Good luck with your quest..... :thumbup:
David D
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BC,
Static convertors use caps to create a phantom phase, here's a link to a schematic that should help you...
http://www.bolis.com/gallery/projects2008/balanced_static_phase_converter
As for fitting a vfd to an ML7, I havent done, but have fitted a vfd to my Chester 9*20 but used a Teco FM50...and a 3/4hp motor.Great conversion...Loads of power when the belt isnt slipping :doh:
More recently I bought a batch of IMO iDrive vfds that were faulty...These were customer returns, rated at 1hp, 240 ac in giving 220v ac 3ph out...Excellent little units and easy to program and wire up..I'm trying to talk my friend into converting his ML7.
All now fixed and sold on thebay for £40 each to very happy customers...So I bought some more!
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Hi John
Did have a vague idea what the wretched things did, just had a desparate hope someone had a schematic of the device in question. Save me the trouble of waving the Fluke at it.
Just had a shufti at the motor, it is a dual voltage type, so I might just have a trip to Drives Direct, just up the road from me, if I can't easily knock it into shape. There's a couple of relays in there, one looks expensive, a Broyce 1OVR, some sort of over voltage doins ... if that's shot, then I'm not going to bother .. either get a VFD or sling the whole damn shebang out the door and get a Wabeco D6000.
It's only money, and I can't take it with me, it seems ... :lol:
BC
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Hi
Dave
I put a VFD from Drives Direct on to my Boxford very happy with it
John
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Give Transwave (Power Capacitors Ltd) a call - they are a very helpful company to deal with. The usual Transwave static generates the third phase as per the diagram posted above, but also has a voltage sensitive relay made by Broyce Controls lookiing at the generated phase. When up to volts it switches out the start bank of capacitors leaving the run bank connected
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Hi
Dave
I put a VFD from Drives Direct on to my Boxford very happy with it
John
Hi John [2] ... :)
Good bit of info, Ta !!
Will get Mr Wilson to nip round and swipe it ... :thumbup:
Cheaper than me buying one ... :lol: :lol:
BC
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Give Transwave (Power Capacitors Ltd) a call - they are a very helpful company to deal with. The usual Transwave static generates the third phase as per the diagram posted above, but also has a voltage sensitive relay made by Broyce Controls lookiing at the generated phase. When up to volts it switches out the start bank of capacitors leaving the run bank connected
Thought about phoning them, there is an LED [?]on the relay that comes on, but as soon as the start button is poked on the lathe, it instantly drops out, as does the other [ Siemens ] contactor.
Depends if that is the faulty component. I've no idea if it is, or whether it's just a symptom.. there are 3 caps in there, I have a Peak LCR meter which will give a good idea if the caps are OK, although I would think it's not a good tool to use on motor run caps. Works fine on electronicy stuff, but only gives the capacitance, not the ESR or anything useful.
BC
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Hi Bluechip ,
have a look at this link :- http://www.machinemart.co.uk/download/PC20-40-60-PHASE-CONVERTERS.pdf
the circuit may help if you can't obtain the circuit for your converter
John
PS for a diy esr meter look here :-- http://mark-lawton.com/capacitor-esr-meter-project/
or http://mark-lawton.com/wp-content/uploads/2010/06/ESR-Capacitor-Meter-Project.pdf
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Give Transwave (Power Capacitors Ltd) a call - they are a very helpful company to deal with. The usual Transwave static generates the third phase as per the diagram posted above, but also has a voltage sensitive relay made by Broyce Controls lookiing at the generated phase. When up to volts it switches out the start bank of capacitors leaving the run bank connected
Thought about phoning them, there is an LED [?]on the relay that comes on, but as soon as the start button is poked on the lathe, it instantly drops out, as does the other [ Siemens ] contactor.
Depends if that is the faulty component. I've no idea if it is, or whether it's just a symptom.. there are 3 caps in there, I have a Peak LCR meter which will give a good idea if the caps are OK, although I would think it's not a good tool to use on motor run caps. Works fine on electronicy stuff, but only gives the capacitance, not the ESR or anything useful.
BC
Give them a call. Years ago I had a Transwave static converter that failed - they sent me a circuit diagram and the Broyce VS relay foc despite the converter being 3 years old. Since then I've had a 7.5 HP and a 20 HP rotary which both ran faultlesly - now I have genuine 3 phase.
I've not heard good reports of the Clarke converters, and I notice from the circuit posted in the link above instead of a proper voltage sensitive relay they are using a normal relay via a bridge rectifier so no settable trip point.
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Woe, woe and thrice woe ...
One of the motor connections has failed anyway ... :Doh:
Now sorting that out, whether it has taken out the Transwave or not .... ????
BC
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Hi Bluechip ,
with luck , once the motor wiring has been repaired, the relay may well hold in as normal
John
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Hi Bluechip ,
with luck , once the motor wiring has been repaired, the relay may well hold in as normal
John
Indeed it does, John .... we have a runner. :ddb: :ddb:
Wrong rotation at the mo', but I expected that. Don't think I've ever had a motor run the correct way first time ... :scratch:
Rebuilt the connections ... what a crappy arrangment. Now has some 2BA CH screws and nuts Loctited in ... now possible to tighten connections ...
Many thanks for the contributions gents ...
BC
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Hi Bluechip ,
that's a good result , just what we want :beer:
considering its a 50: 50 chance , on a good day I manage to get the direction wrong 70% of the time :lol:
I'm sure some where I've have a simple circuit to display the phase sequence for a 440V 50Hz supply
John
found it! -- single phase indicator and 3 phase sequence indicator using NE2 bulbs
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Hi Troops
The static converter has gone pop on my Myford S7. It appears to have lost a phase. :zap: :scratch: :bang: during the arduous task of tapping a M4 thread in brass.
As the thing appears to date from Nov. 1991, I am not inclined to faff around with it too much.
The output is 415V, or rather was when it was alive. Now have phase to phase volts of 422V / 0V / 411V
[1] Anyone got a schematic of the damn thing ?? If it is just a shagged capacitor I might just give it the benefit of the doubt and refurtigrate it.
[2] Anyone fitted a Newton Tesla VFD to a S7, if so, why are there apparently 2 versions ? ie 1/2 HP & 1 HP ?
The Transwave one I have is 1/2 HP. I see no point in fitting a larger one, but is there a reason why more grunt would be an advantage ?
A much miffed ...
BC
I fitted a newton tesler didn't get it all boxed just motor and controller (cheaper) for my ML10 took 5 min to wire up they are very helpfull I got a new motor at same time it,s a bit bigger than 1/2 HP not much and he said they fitted these on ML7s as well he programed it all up took the brake right down so the chuck doesent unscrew and is helpfull if you have queries great people to buy off , oh and 5 min from my house :headbang:
Peter
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Hi Peter
Did have a look at the N-Tesla solution, but I'm not very keen on the motors. Transwave do some 3/4 HP jobbies which appear to be TEFC motors. [ TEK ?? ].
Myfords have a nasty habit of sucking crap into the motor, despite their crude attempt at a shield.
So, if I kept the machine, I would not really consider the ones with vent slots. My old ML7/T had two motors ingest crud and go pop in no uncertain fashion. :zap:
I'm thinking of dumping the S7 in favour of a Wabeco, even if I fitted a VFD to the S7, it won't do anything about the miserable sized hole thro' the mandrel ... :( which is a constant source of annoyance to me. The only caveat being the Wabeco has no SC gearbox, but then I don't do much screwcutting anyway.
BTW Mr. Swift ...
I like the ESR circuit, may just have a bash at that .. :thumbup: I seem to have most of the bits ..
As for the lathe going the wrong way ... how can I put it ?? ... Maybe I should have looked at the Motor FWD/ REV switch on the control panel first ... :doh: :doh:
I think I might need a Carer ... :scratch:
BC
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As for the lathe going the wrong way ... how can I put it ?? ... Maybe I should have looked at the Motor FWD/ REV switch on the control panel first ... :doh: :doh:
I think I might need a Carer ... :scratch:
BC
Heyup Dave!
Remember our last little fumble, with my little lathe?
After you'd departed. I found it went faster, in reverse.......... :palm:
Consistency! :thumbup:
Swapping the motor wires around, sorted things. :D
(It's still pulling like a train)...... :beer:
David D