Nilfisk-Advance Advenger 2800ST Quick Start Service Manual page 35

Service Manual – Advenger, 2800ST, 3800ST, BR 755, BR 855 SCRUB SYSTEM 35
ST - with the seat switch closed, lowering the squeegee and brush deck and pressing the drive pedal forward causes the brush and
vacuum contactors to energize. The 24V brush and vacuum motors turn on; the pulsed solution solenoid turns on. Combined brush motor
current is monitored via the YEL/VIO sense wire. Reversing the drive pedal turns off the solution solenoid, but the brush motors stay on
(for double scrub).