Fanuc servo question...

[Jonne]

Hello!

I'm little bit confused about Fanuc servo voltages.
In question is Fanuc 1,5 Kw getty's.
What is full speed driving voltage?
I'm understand half of alternating current is used each direction.
So, if full bridged DC is 200V then full speed voltage 100 V.
Am I right?

[guhl]

Originally Posted by Jonne Hello! I'm little bit confused about Fanuc servo voltages. In question is Fanuc 1,5 Kw getty's. What is full speed driving voltage? I'm understand half of alternating current is used each direction. So, if full bridged DC is 200V then full speed voltage 100 V. Am I right?

Can not understand what do you mean exactly. The thing is: every DC servo rectifier has thirystors and diodes or transistors. So, you may obtain that voltage you need (in case of using thirystors frame changes burning angle, in case of using transistors the frame uses PWM). The required voltage you need is been determined by type of motor you utilize (see rate plate).

[Jonne]

These servos ( and servo transformer ) are from Nagamura TMC-4
lathe with Fanuc 6T-b. I don't have Fanuc's servo controllers,
I'm using controllers which use DC, not AC like Fanuc.
And these my controllers do not have 12 thyristors.
So, how I rectifier electric for DC-controllers?

Ps. Sorry my poor english, I'm from Finland...

[gridley51]

Jonne,what servo controller do you have?Most machines built with a Fanuc 6TB control used dc servo motors and drives.

[Al_The_Man]

If they are Getty's/Fanuc they are DC especially if they used the old SCR drives. these motors usually ranged from 90vdc to 180, they were restricted to around 2000rpm max.
what you can do is is to apply a known DC voltage, two auto batteries in series for e.g. and measure the rpm at this voltage, you can then calculate by extrapolation what voltage it would require for 2000rpm or whatever the label rating says.
If you are using PWM drives for example, then you will need to build a suitable DC power supply, If it is not built into the drives.
Al.