3ph reassurance required !

[Scrums]

Hi all,

3 phase has always been a closed book and a mystical black art to me....
but, having spent well over £500 notes over the past couple of years to electricians who seem to feel it's their god given right to charge the first figure that comes into their heads :x

I think I have suddenly made a personal discovery - all I want is that 'pat on the head' and yes scrums, it really is that simple....

I have a 'new' pillar drill - a Viceroy 20 in very nice nick, out of which's conduit come 3 red wires and a green. On the wall is a 3ph isolator, within which I expect to find a similar combination of wires - connect reds to red and earth to earth and away we go? (...remembering to turn off power at box first - )

hmmm.......

Chris.

PS: and the first person that 'tuts' and says you must have a trained spark is considerably richer than me!

 

[JonnyD]

Yes its pretty simple. You may find your motor is going backwards if so just swap over 2 of the red wires and it will go the right way.

cheers

jon

 

[OldWood]

"Pat on the head" granted - and a sugar lump too !

And it really is that simple !! What confuses people is the fact that there are three 'line' wires - but as you say, Scrums, if there are three wires wanting connected to something then what looks correct usually is.

And as long as you take into account that if the motor turns the wrong way, all you have to do is to change over two of the connections.

In fact wiring up a three phase set-up is a damn site easier, and less likely to give bother, than a single phase motor with a starter coil and can connected for reverse running viz. that on my Myford 7 lathe, which I always have to remember to record if I'm taking the motor off (and usually don't!).

Rob

 

[big soft moose]

Yes its pretty simple. You may find your motor is going backwards if so just swap over 2 of the red wires and it will go the right way.

cheers

jon

many thanks jonny - I think have just discovered why my mate matts tablesaw is spinning backwards - and that's had us flumoxed all week, and that was wired up by a trained sparky too

just to be clear is it a case of swapping over any two of the red wires , or is it a particular two and a case of trial and error to find the right ones ?

 

[bubbabear]

Any two line wires swapped will change the direction the motor turns.

 

[OldWood]

Yes its pretty simple. You may find your motor is going backwards if so just swap over 2 of the red wires and it will go the right way.

cheers

jon

many thanks jonny - I think have just discovered why my mate matts tablesaw is spinning backwards - and that's had us flumoxed all week, and that was wired up by a trained sparky too

just to be clear is it a case of swapping over any two of the red wires , or is it a particular two and a case of trial and error to find the right ones ?

Ah but the sparky wasn't a trained wood worker so he wouldn't know the blade was going backwards. Failure in Customer Acceptance of work undertaken !! Your fault not his.

Rob

 

[9fingers]

Hi all,

3 phase has always been a closed book and a mystical black art to me....
but, having spent well over £500 notes over the past couple of years to electricians who seem to feel it's their god given right to charge the first figure that comes into their heads :x

I think I have suddenly made a personal discovery - all I want is that 'pat on the head' and yes scrums, it really is that simple....

I have a 'new' pillar drill - a Viceroy 20 in very nice nick, out of which's conduit come 3 red wires and a green. On the wall is a 3ph isolator, within which I expect to find a similar combination of wires - connect reds to red and earth to earth and away we go? (...remembering to turn off power at box first - )

hmmm.......

Chris.

PS: and the first person that 'tuts' and says you must have a trained spark is considerably richer than me!

Excellent Chris!! It really is that simple.

With your new found confidence, try downloading my paper on induction motors and each night before going to sleep, take two aspirin and read a page or so and see how you get on with it.

Good luck

Bob

 

[OldWood]

"Excellent Chris!! It really is that simple.

With your new found confidence, try downloading my paper on induction motors and each night before going to sleep, take two aspirin and read a page or so and see how you get on with it.

Good luck

Bob"

Significantly better than counting sheep ! Bob will guarantee you a good night's sleep. :lol: :lol:

Rob

 

[9fingers]

Thanks for that ringing endorsement Rob :twisted:

Bob

 

[Scrums]

Many thanks to those who gave encouragement, my brand new secondhand pillar drill now works!!.....OK, first go it went backwards, but then I knew what to do didn't I :lol:

Yes Bob, a thrilling read it is too - I have d/l it and barely understood a word....though I did recognise some of the bits in the piccys....seriously though I will use it at some stage to help me put the inverter I bought 3 years ago on the Wadkin lathe

Cheers guys,

Chris

 

[OldWood]

Hi Scrums - what Wadkin lathe do you have ?

I've a BZL 6 - I don't know all of its history but it has a modern 3ph motor and a Drives Direct inverter.

The previous owner came to wood turning from metal turning and I suspect that he thought it was just a transfer of skills ! I had to make up an 'on-machine' control panel and sort out the emergency off circuitry.

If you want some help let me know.

Rob