First time poster so some quick background - I'm a small, one-man shop that does work on the side for various self funded projects as well as some decent paying work for local companies. I have a regular day job at the moment but hope to make the fabrication business full time some day.
I have a few questions: I recently acquired an LB-12 with OSP-500L-G control (green screen) that I'm running off of a 25 hp phase converter. I haven't done much work with the lathe yet but everything seems to work okay with the exception of deceleration. If I'm running the spindle at a given RPM then command a spindle stop, I get large voltage (don't have the numbers with me here) spikes in the line voltage as measured at the disconnect switch. I understand that some newer machines feed the power generated during braking back onto the grid, but I can't imagine that my 1988 vintage machine would have such a feature. I'm wondering if there are some braking resistors or other electronics that may be burned out? FYI there aren't any control or spindle drive errors.
Along the same lines (and maybe this would be enough to solve my problem), is there a parameter or adjustment that can be made to limit the spindle acceleration / deceleration to some lower level? The lights dim somewhat when I start the spindle and I'm not trying to make thousands of parts with the machine, so if I loose a little bit of my efficiency having to wait for the spindle that's fine with me.
Any help or feedback/comments would be greatly appreciated!
Thanks!