I moved house a few years ago, but sad to say did not get either 3 ph or lathe as part of the deal !

Lucky you ! Fear not, someone here will sort out your problems.

Starter may simply be burned out. I would just buy a new unit ant take it from there.

Paul

More info re make and type of starter and motor would help to give some advice, pictures speak a thousand words.

Emgee

If your garage is covered by your house insurance, it might be necessary (or at least helpful) to get the electrics checked by a qualified electrician, and a form signed saying what he checked and found OK. Unless of course you are such a bloke, in which case you ought not to need to ask questions like this.

Just a thought – its your garage and your life, after all.

Cheers, Tim

Paul if you have a meter as you have checked the resistances of the windings then with the power off check for resistance on the contacts of the contacter when you press the contacts together.

then check resistance of the coil on the contactor

Before you jump into electrics, can you turn the lathe by hand?

Either at the chuck or belt /motor. It the spindle is locked you will get an electrical overload. Mis-cordinated controls could lock the spindle.

Robert G8RPI.

Quite true. But the most likely scenario is that one touches a live conductor while another part of you is earthed. Nominally mains neutral is at earth potential and relative to neutral "live" is 230V. But relative to neutral each line of a "415V" 3-phase supply is ALSO at 230V. The 3 phase is 415V phase-phase voltage. So touching one of the phase wires from a safety point of view is no more dangerous (which isn't to say that it's safe!). If you connect yourself phase to phase of course it would be a different matter.

Whatever, whether 1-phase or 3-phase, mains electricity is dangerous and should be treated with respect!

Power OFF, use a multi meter, of course – as per Howard.

I say ‘Pull the fuse as well’. I put the fuse in my pocket, if apppropriate. Most circuits are protected/controlled by MCBs these days – you don’t want anyone to inadvertently switch one back on!

And if you happen to be checking mains connections while energised, please use a multimeter which is safe for those operations – many are not and some that are ‘reasonably’ safe may not be, when in inexperienced hands.

One lad, I remember, finished up on the wrong side of the room, but luckily without the crucible he was rushing to remove from a laboratory kiln at 1200C! Another was an electrician who was thrown off a gantry some 15m high but luckily landed on the side of a heap of not-too-hot clinker which cushioned his fall.

Back of hand towards possible contact points is always a good idea, along with the other hand in your pocket – less chance of grabbing hold of a DC supply or getting a shock across your ticker.

To really be able to do a diagnosis we meed pictures of motor, inside motor terminal block, and inside the starter, but check the following in this order. all with power OFF!

Remove belts and turn the motor, it should spin freely and cary on for a rev or two when given a hand spin.

check for any motor bearing play which could be allowing the rotor to touch the stator.

wrap a couple of turns of cord round the motor pulley and give it a brisk pull, does the motor still spin freely?

Check the motor rating plate and see that it is a 3 phase motor!

Remove the motor terminal block cover and check the connections and the visible condition of the insulation.

Check the smell of the motor, it should smell slightly of varnish and oil, if it has a very strong burnt pungent smell, it is the motor windings that have failed.

The motor will be star connected, three coil ends will be connected together on a spare terminal, and the other three ends will have one phase each connected to them, I am assuming the motor is a similar age to the lathe, and does not have the star connection point buried in the windings,

With a multimeter set to resistance, connect one proble to the star point, and then test from each phase in turn, all readings should be virtually identical within 1-3 ohms of each other is ok.

You really need a megger tester to check the motor windings insulation from earth, but if you get any reading with a multimeter from the star point or any phase to earth (motor case) be suspicious that the motor is at least damp, and needs drying out. If you have or can get someone to megger test the insulation you want at least 1Megohm to earth. Hold the megger test on, or keep winding if it is a wind the handle megger, and if the reading starts to improve, the motor is damp, use a fan heater, hot air gun or even domestic oven on low to dry it out.

Check the belts are not catching anywhere.

Turn the lathe belt pulley, Is the lathe in gear? Is the clutch (if fitted) engaged or disengaged? disengage the clutch, and put the machine out of gear so that the chuck does not turn when the lathe pulley is turned, and then check that the lathe pulley turns freely.

In order to diagnose the starter, we need an internal pic, and also one of the motor plate and inside the motor terminal box. Does the starter "chatter" when the green button is pressed, ie does the amature jump in and out rapidly and repeatedly, if it does you have confirmed that the coil is working (in some way) so the next check would be the holding in contacts, and the overload tripping contacts, but without knowing what type of starter it is I can go no further at the moment, hope this helps!

Phil