Nilfisk-Advance CS7000 Fuel Cell EcoFlex, Service Manual

Page: 318 / 440

318 Service Manual – CS7000 318
Solution System
Functional Description
Overview
The solution system delivers water, or detergent and water, to the floor for the scrub system. The solution
system includes the solution tank (main body of machine) and solution pressure (level) sensor, solution
shutoff valve, solution filter, solution pump or pumps (some models), solution solenoid valve, and the
associated plumbing to distribute solution to the nozzles at the three scrub brushes. A capped solution drain
hose allows you to drain the solution tank.
The solution flows to the scrub brushes any time the scrub system is enabled, the scrub deck is lowered
and the drive pedal is not in the neutral position. Programming options allow you to enable or disable
solution flow when the machine moves in reverse. When the scrub system is disabled, no solution will flow
to the brushes regardless of drive pedal or scrub deck position. The operator can enable the solution system
independent of the scrub system to pre-wet the floor before enabling the scrub and/or recovery systems.
Solution Flow Control - Non-EcoFlex™ Machines
On the non-EcoFlex™ machines, an electrically-activated solenoid valve controls the solution flow. The
solution is gravity-fed to the solenoid valve, and the solenoid valve output volume is controlled by the Main
Controller through a PWM (pulsed width modulated) output. The A1 Main Machine Controller monitors
the solution level via a solution pressure sensor. (Also refer to the Component Locations/Solution Tank/
Solution Pressure Sensor section.) As the solution level drops, the PWM output will increase to compensate
for the loss of solution (head) pressure in order to maintain a consistent solution flow rate regardless of
solution level in the tank. The solution solenoid’s coil circuit opens and closes (pulsing on and off), pulling
the valve diaphragm on and off its seat. This way the A1 Main Machine Controller can manage the three
different auto flow volumes and two different override flow rates.
On non-EcoFlex™ machines, the operator must manually mix the detergent with the water in the solution
tank if detergent is desired in the solution.
Solution Valve Desired Flow per Solution Setting
Solution Flow Setting Desired Flow (GPM)
1 1.0
2 1.5
3 2.0
4 2.5
5 3.0
Solution Flow Control - EcoFlex™ Machines
EcoFlex™ models use a solution control pump (
M19
) to supply the solution to the scrub brushes. On
EcoFlex™ machines, the solution solenoid valve remains open when the solution control pump is running
and the solution flow is controlled by the pump output. This allows more precise mixing of the detergent/
water mix to the brushes. The EcoFlex™ detergent delivery line is plumbed into the solution line between
the solution pump and the solution solenoid valve.