On 04/08/2013 20:40, mick wrote: ...
Most three phase machines I worked with came with three red wires and, sometimes, one black.
...
I think there is some natural law that they will always run the wrong way when you first connect them, ;-)
Colin Bignell
I know there is some natural law that they will always run the wrong way when you first connect them. Especially if it matters.
After about 2 hours struggling, I finally managed to get enough clearance u nder the motor box lid to swap the config over from star to delta. So am no w looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.
On 06/08/2013 13:56, snipped-for-privacy@virgin.net wrote: ...
The lack of follow-up postings to tell us all went well is slightly worrying.
Colin Bignell
Any big flashes seen recently, other than lightning?
ce under the motor box lid to swap the config over from star to delta. So a m now looking at the Big Switch On sometime this afternoon and hoping for z ero explosions or flashes/bangs as I don't think my nerves can stand it.
Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothin g happened. Nothing at all. Completely dead. Having done a bit of research on the net, it seems one has to connect the o utput of the converter direct to the motor. I'd actually connected it to th e lathe's existing 3 phase cable which goes off into a complex switchbox ex pecting 415 Volts. The converter's output is 3 phase alright, but at only 2
30V. Obvious in retrospect, but an easy error to make at the time. Unfortunately there's a so-called 'suds' motor which powers the coolant pum p and it requires 400V. If that turns out to be dual voltage too, then I co uld connect it up delta and power it from the converter, but then the coola nt rate will vary in tune with the main motor speed control provided by the converter! It might be simpler to swap the suds motor for a 230v one.
ce under the motor box lid to swap the config over from star to delta. So a m now looking at the Big Switch On sometime this afternoon and hoping for z ero explosions or flashes/bangs as I don't think my nerves can stand it.
Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothin g happened. Nothing at all. Completely dead. Having done a bit of research on the net, it seems one has to connect the o utput of the converter direct to the motor. I'd actually connected it to th e lathe's existing 3 phase cable which goes off into a complex switchbox ex pecting 415 Volts. The converter's output is 3 phase alright, but at only 2
30V. Obvious in retrospect, but an easy error to make at the time. Unfortunately there's a so-called 'suds' motor which powers the coolant pum p and it requires 400V. If that turns out to be dual voltage too, then I co uld connect it up delta and power it from the converter, but then the coola nt rate will vary in tune with the main motor speed control provided by the converter! It might be simpler to swap the suds motor for a 230v one and just run it o ff a 13A socket.
At least you are still with us :-)
They are cheap enough, assuming you don't have one like I had in a tool and cutter grinding machine. The motor casing was part of the machine casting and, when the motor failed, the only option (the manufacturer being long gone) was to send the entire machine away to have the motor re-wound.
Colin Bignell
ance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.
thing happened. Nothing at all. Completely dead.
he output of the converter direct to the motor. I'd actually connected it t o the lathe's existing 3 phase cable which goes off into a complex switchbo x expecting 415 Volts. The converter's output is 3 phase alright, but at on ly 230V. Obvious in retrospect, but an easy error to make at the time.
pump and it requires 400V. If that turns out to be dual voltage too, then I could connect it up delta and power it from the converter, but then the c oolant rate will vary in tune with the main motor speed control provided by the converter!
I have a bit of luck in this regard. I removed an old jacussi bath a few mo nths ago (don't think it had ever been used) which came with a 230v motor a nd a pump, which for some reason I thankfully held on to. They're in a sing le unit and should be ideal for use squirting coolant at hot spinning metal .
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