An interesting follow-up on this. Electrically everything worked OK but the load sharing was very poor. While most of the right questions were asked - identical motors and gearboxes it turns out the existing drive pulleys were a (slightly) different size.
Since the motors are high efficiency...
As Roy noted, a 2300V VFD is expensive to the point where buying identical motors is more cost effective. A 600V VFD is cheaper and could be run is some form of current limit or droop mode, but having one motor on 2300v and the other on 600v becomes a major hassle for lockout procedures.
I...
We've got a conveyor that we're upgrading from 1 x 350HP motor to 2 x 250 HP Motors. Both motors will run from a single starter with individual overload protection.
The problem is that the motors are not identical; close but not exact. They are both Tatungs and 2300V 250HP but one is 1775 RPM...
Thanks Petronila
The thread did have usefull info, especially the post by wiretwister. The battery and meter method is easy to use.
I should of found that post myself but didn't use the proper keywords in my search. Thanks for your memeory or searching skills.
It was a nasty place to work...
I'm trying to hook up a 600V, 200HP 3 phase squirrel cage motor. It had six leads with no identification tags. It's 4 pole at 60 Hz. It drives a fan so reverse rotation for a short time is not a problem.
I can identify the individual winding pairs. We're using it in Delta with across the line...
