Shunt wires on BLDC controller

Hello everyone
I have a 3kW, 60V BLDC controller. There are 4 heavy jumper wires in brigde shape on the PCB. Someone told me they are shunt wires. I tried to google it but no help found?
Can anyone tell me what are the functions of there grounded shunt wires which are connected to the 'Source' to ground terminals of the 3-phase MOSFET bridge of the controller?

Any help will be great.

Here is its picture.

hey are a "resistor" used to measure the current flowing through the controller.

Thanks 'Manny' for the reply.

Can you also tell me why 4 wires instead of 3 wires?
And why are they in a bridge shape and not on the pcb board?

the number of parallel wires lowers the resistance.

naeemdotcom said:

And why are they in a bridge shape and not on the pcb board?

Click to expand...

do you mean smd? i think power dissipation. the wires will heat up when passing high current.

Thanks a lot 'Manny'