Thread: Electrical problem with a lathe

(With the power disconnected) have you resistance across each of the windings?
If it was single phase I'd suggest the start coil had burnt out, but with 3 phase??

Michael

I assume its standard 3 phase

measuring to earth can result in back feed thru windings giving the impression that you have all phases...ideally measure across 3 lots of two phases at the bottom of the contactor...ie
red to blue
blue to white
white to red
each reading should show 415V or there abouts

make sure the motor has equal resistance across all three windings

I had a problem similar to that many years ago on my Takisawa (not sure if it was exactly the same problem) but what caused it was at the headstock end of the forward/reverse/stop lever the cams that work the switches had come loose and weren't doing their job properly, just follow the rod along(if you have one) and where it goes into the headstock base remove the cover and have a look-WITH THE POWER OFF, you will be able to work out if the cams are loose.
Will

The forward reverse rod and cam have 2 limit switches and they are working OK.
It seems strange that the Coolant pump isn't working either.
I might wire the power lead directly to the motor and bypass all the contactors and see if she will spin.

Sounds like you've lost a phase, and somewhere upstream I'd guess if the coolant pump isn't running either.

Regards
Ray

Thanks, Ray.
A mate is coming to have a look on Friday.

I thing RayG might be on the right track there.

I sometimes have a machine that will just hum when I switch it on and all I do is push the plug into the socket a bit firmer.

Originally Posted by RayG

Sounds like you've lost a phase, and somewhere upstream I'd guess if the coolant pump isn't running either.

Regards
Ray

yep that was what I thought


I wonder what it was? I wish he would report back...!!!

Mate couldn't make it.
The sparky that fitted the new main switch to the meterbox is coming back this Friday to fix his FUBAR...
I'll let you know the outcome.

Originally Posted by glock40sw

Mate couldn't make it.
The sparky that fitted the new main switch to the meterbox is coming back this Friday to fix his FUBAR...
I'll let you know the outcome.

appreciated...ta

glock40sw......being a SW revolver and STI owner I beleive you need to spend some decent money and get a real gun.....

Originally Posted by eskimo

appreciated...ta

glock40sw......being a SW revolver and STI owner I beleive you need to spend some decent money and get a real gun.....

Ha.... The Kimber and SVI race gun more than make up for the Tupperware.

Originally Posted by glock40sw

Ha.... The Kimber and SVI race gun more than make up for the Tupperware.

they do indeed....???well I'm not so sure about the Kimber either..but the SVI does

Well. Mystery solved.
The sparky rocked up this morning and looked over everything. When he fitted the new 3 phase main switch, he placed 2 active wires for the shed main switch into the same active connector. Thus I only had 2 active phases in the shed. but when you placed a test light across the 3 actives in the shed it showed that they had power. but when the test light was put from active 1 to active 2 there was no light.
So now the lathe is operational again and turned up a few nylon spacers today.
Life is good with 3 phase.....

Now that should be worth some discount for all the inconvenience he caused, and the lost time etc. I'm glad that's all it was though.
Rob.