Pantograph "lower And Sand"

Hi, I noticed today that some Pantograph controls have option to "sand". Is this to sand something on the pantograph, or the wheels?
If so, then why is it needed?

 

I dont know.

I've always thought what t does too

 

It‘s sand for the wheels. In Germany, sand is not supposed to be used to increase traction when starting a train, but rather to increase adhesion in case of an emergency brake application. If the reason for the emergency is on the loco (think of a fire etc), lowering the pantograph and cutting out the main circuit breaker would be your first steps - the lower+sand notch does that for you while also activating the sanders for the emergency brake application you‘ll do next.

 

Thanks for that, was curious.