3-step electropneumatic brakes

[straller]

Hello,

Can anyone tell me technical information about the 3-step electropneumatic brakes used on most UK multiple units? What wire opens what valve how do the pneumatics look like (a schematic or something)?

 

[carlejo]

is this ok ?

 

[straller]

is this ok ?

Thanks, but it didn't explain any of the pneumatic systems. Are there any schematics of the brake system that show what happens in there when the train wires are de-energised?