Working on the Hurco

[Bob La Londe]

I may have to break down and put a new motor on this, but I would like to use it if I can. 

I seem to recall that the guy I bought the mill from siad the guy working on it was having trouble getting the spindle motor figured out before he died. 

It is a Leland Model 6273 3 phase 240 volt motor.  The data plate say 5HP.  That's a lot for a mill this size.  Anyway.  Before scrapping the motor (which will be a trick if I do because of the weight) I thought I would see if I could figure it out.  Its got 6 moderate size black wires and 2 smaller brown wires coming out of the motor.  The two brown wires I suspect are for a tach or some other sensor so I just tied them back out of the way for now. 

The six black wires are unlabeled.  I did a quick check with an ohm meter, and found that they are in groups of 3.  In one group of 3 any 2 read about 20 ohms, and in the other group any 2 read about 2 ohms. 

The data plate reads:

Leland Electrosystems Inc
Model 6273 
Serial TX43042
FR 215
HP5
HZ 3/130
C Temp rise Cont.
NO.71
RPM 96-3680
Class H insulation

[Dragonfly]

LOL I did a Google search and the first hit was your question at another place
It seems the manufacturer does not have a site which is strange.

A shot in the dark - it seem to be a double winding motor, maybe one starting and one working or both work in combination to achieve variable speed, or reversing. In any case there must be a controller block for the motor. I do not exclude the presence of an inertial commutator inside the motor.
It may be even a dual voltage motor but I am not sure what voltages are the standard at your place. Here single phase is 220V, three phase is 380V. 240V (AFAIK standard mains voltage in the UK) seems to me like single phase.

If you take it down, a person who does rewinding of motors would be able to identify. Or you can ask in a shop where they do this if there's one around.

Look at this link
http://www.practicalmachinist.com/vb/transformers-phase-converters-vfd/single-phase-dual-voltage-six-wire-motor-wiring-159221/
maybe same type of motor.

[swarfing]

You mention 2 "smaller' brown wires? these could be a brake? does the motor protrude a bit on the back end?

[Dragonfly]

Or a thermal protection circuit. This is mentioned in the link I posted.

[Bob La Londe]

Ok...  I got it figured out.  Mostly...  Its got an independent fan motor.  Doh!  Had I been a bit more observant I would have seen that myself, but somebody in another group pointed out the possibility, and commented on the probability because a motor turning only 96 RPM at 3 Hz can't possibly be turning a fan fast enough to cool itself. 

It was easy enough to check.  I spun the fan and held the brake disc on the motor with my other hand.  Wheeeeeeee!!!

It has six primary leads because there are two motors. 

I suspect the 2 smallish brown wires are a thermal sensor.  Not sure I can test it except maybe...  to wire up the motor and not the fan motor.  LOL. 

[Dragonfly]

Better not risking motor health
I at least learned today something new, I'd never seen such a motor with a separate cooler motor buit-in.
If there's continuity between the brown wires and very low resistance it may be a bi-metal circuit breaker switch. If it is a thermistor it should change its resistance even if the motor is only warm or if you blow some hot air at the place it is located.

[kvom]

Every 3-phase motor I've ever seen (although that's not a lot) has 6 wires.  They get wired together in pairs according to whether they need a Y or a delta configuration.   Of course, without number tags on the wires getting the pairs correct isn't obvious.

[Bob La Londe]

I understand what you are saying.  This motor is obviously (now that I know what I am looking at) 2 motors already setup as delta with just 3 wires coming out of the case for each motor.