I'm in the process of finally getting a rotary 3 phase converter going with
a BIG pilot motor but I'm confused by the motor rating. It's a 4kW 2850RPM
Brook Crompton motor to BS5000, frame 3D112MD, serial D102709, 415 delta
(symbol), rating MC, design 2E.

The bit that I'm not sure about is whether to leave it delta or re-connect
it as star (there are 6 terminals so it's easy to change). My limited
understanding was that: smaller motors would normally be wired star for 415
and delta for 230 (eg with an inverter); larger ones would normally be
started in star and then switched to delta (or the other way around if max
starting torque was required).
With a converter there is negligible starting torque needed so I would guess
that star would be the answer BUT when the load motor is started I assume a
lower source impedance would be good and therefore a delta pilot might be
better. Aaargh - onset of brain fade.

The motor is marked "4kW, 415 delta" will it still act as a 4kW motor if
wired in star?
Which is best for a converter, star or delta?
Can anyone decode the rating, design and frame codes?

Dave S