-48 VDC BLDC motor?

I have a small air conditioner which has this compressor with -48VDC rating and all, even PCB has -48 VDC written on it, and yes sir i have googled it a lot before posting this here but i can't be able to find anything, can anyone please tell me what it is and how it works?

any schematic to control this type of motor will be great too, Thanks.

Photos? Sure its BLDC?