OT: Motor Question

We have an old liquid ring vacuum pump sitting in the parts area, and its been there for years. I got curious about it, was looking at it, and the motor plate confused me. What are they trying to tell me with the Delta Wye designations, and what the heck is 346 Volts? The deltas seem to correspond to one leg of the higher 3 phase voltage, and I found one source that indicated that Hong Kong once used 346 volt 3 phase 50 Hz.

I try and help you out
In this case the nameplate gives you a lot of information
Sometimes too much information is overwhelming when that happens you just need to stop take a minute and think about.
That motor was designed to be used in multiple countries, different countries have different electrical standards.
This motor is a 3 phase 2 pole motor with a bases speed at 60 hz of 3600 rpm and at 50 hz of 3000 rpm
It is also Dual voltage motor
From the connections, it would have 12 motor leads most dual voltage motors have 9 leads
The can be a little confusing at first
Also I would think the motor leads would follow the UE standard
U1 V1 W 1 U2 V2 W2 U3 V3 W 3 U4 V4 W4 on a terminal block not the wire leads we see in the US

This motor would have 6 windings the winding can be connected in
Low voltage 2 Delta or 2 Y configuration the windings would be in parallel
High voltage 1 delta and 1 Y configuration the windings would be is series
The posted rpm’s are shown with the motor running at it rated load and rated slip
All motor name plate show the rpm’s at rated load and slip.
In North America the normal line frequency is 60hz there are some odd ball out there.
You select the motor connections for the normal line voltage where it is to be used.
As shown the rated power is reduced by the same amount as the line voltage is reduced
As you can see as line voltage goes down the amps go up for the power output (Every thing has to balance)
It was most likely manufactures someplace in the EU (KW) and (IP55)
Also it would normally be running a little the hot side (40C ) that 104 F but abnormally high
They don’t say rise so the assumption would be its operating temperature
Most us motor are rated 25C rise with the normal ambient temp at 25C they too would run a little on the high side. With all motor you must consider the ambient temperature where the motor is be installed.
The show most of the different operating voltages but you could also use it on other voltages and frequencies, just calculate V/F and go from their

I hope that helps
All this information is available on web

It has the mandatory CE marking in Europe but none of the voltages matches the standard in Europe which is 400V 50HZ

I think your North American equivalents are 208v 347v and 277v. The 480v is pretty normal, same with the 40 degrees Celsius rise.

Interesting that the efficiency is higher at the lower voltages. I don't think you can use that motor though, no UL markings.