Copeland 6RP2-3500 TSE Puzzle

[piewie]

Hello Everyone
Today I came across something new, or rather new to me. The plant is fairly old and not well maintained so drawings are really not available. Can anyone help.
The compressor is/are a Copeland 6RP2-3500 TSE and the nameplate has them at 565volt/60 Hz or 500volt/50 Hz.
The plant is 415v 3phase and the wiring to start with would have one believe it was a star delta starter. However at a closer look it there is only one 3 core cable going to the compressor and there is transformer which seems to be connected to a contactor but only on two phases. Anybody have any ideas?

Many Thanks

[Grizzly]

Hi Piewie.
First attachment in the btm l/hand paragraph explains what you MAY have?

Attachment 8656

Attachment 8657

Attachment 8658

I hope these help?
Grizzly

[piewie]

Thanks Grizzly I will take a look.

[Magoo]

Possibly an auto transformer starter for low voltage start, with four contactors for a closed transtion.

[aramis]

If there is not a neutral, the transformer is to feed the contactor coil with the required voltaje like most of copeland's diarams show.