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Machine power hookup, transformer question *pics*

D. Rey

Titanium
Joined
Jan 20, 2003
Location
Phoenix, AZ
Machine is a 94 Nakamura TMC-15 lathe





wiring diagram from manual, left side looks like my setup, right side appears to have an external transformer?


DSC_0890.jpg



wires from shop into base, to taps labeled Ro,So,To, to top of circuit breaker and out to machine.

DSC_0881.jpg


This is what I am uncertain of. Pic is of the transformer to the right of the circuit breaker in the above picture.

Looks obviously like transformer taps, S3 was on 210, I moved it to 230 as I have 240V in, I left the screw on 210 out so there are no missing screws, no loose wires. Where is the third leg? There is no mention of this particular transformer in the book I just ASSume it's the machine transformer, think this is correct?

I have not put power to the machine yet.


DSC_0883.jpg
 
You're most fortunate your Nakamura was designed for 200-230. Many Japanese machines are designed for 200, only.

You may want to evaluate your feeder with the help of the utility, and than plan for a slight "buck" to get the voltage down to the required range.

For the general case, you would need an external transformer for more than 240, but 240 is nominal in the U.S., whereas actual could be 235 to 255, in my experience.
 
Voltage spec is 10% high side and 15% low side.

Question does that allow for the transformer adjustment? ie 230 +10/-15% or is it 220V +10/-15% as the plate on the back of the machine says 220V?

Also, Does this make sense just two incoming legs to the transformer?

Every other machine I have hooked up (3 others Fadal, Haas and Mazak) had all three legs going into the transformer.

Dave
 
I'm electrically challenged sometimes, but that looks like a control voltage transformer. If so, it's only making single phase power so it only needs 2 wires in.
 
Good call on the transformer, mudflap.

The size is made clearer when you see the transformer in the background
in the upper photo.

The fact that one end of the winding is *bonded* with the green/yellow stripe
wire pretty much says it has to be the control transformer.

Jim
 








 
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