Washtech XP Series, Service Manual

Page: 17 / 44

PressureSwitchFill
Part Number
600 30479
Function
Controls filling of wash tank and protects wash elements.
Description
The pressure switch is attached to the pressure bell. As the water level in the wash tank
rises air is trapped in the bell and increasing pressure is transmitted to the pressure switch.
When the tank is full the pressure switch shuts off the fill solenoid valve and switches on
the wash element. It allows a water level differential so that the tank level may drop with
the operation of the wash pump, without causing refilling of the machine.
Diagram
LEVEL ADJUSTING SCREW
CW rotation increases upper level
setting – fill level
DIFFERENTIAL SCREW
CW rotation increases
differential and reduces lower
level settings – refill level
Adjustment
Before making any adjustments; drain wash tank, remove pressure tube from pressure bell,
blow gently into tube to check switching of pressure switch and then fit tube back.
Turn the power switch on, machine should start to fill. The machine should cease filling
when the water attains a level about 10mm below an overflow level of the upstand. Adjust
fill level if necessary by Level adjusting screw on the pressure switch.
Select drain cycle, remove drain upstand and close door to begin draining the wash tank.
Listen for a click from the pressure switch when water level in a wash tank reaches refill
level. Then stop the drain cycle by pressing the Start button or by opening door. Fit back
the upstand and measure the refill water level. The refill level should be set 10-20mm above
the wash element. Adjust if necessary by Differential screw on the pressure switch. Close
door to refill the wash tank and re-check the fill level.
Replacement
To remove the switch take note of the electrical connections and remove the wires. Slide
the switch from the mounting bracket and remove the rubber tube from the switch
connector. Replace in reverse order. Whilst in the process of replacing the pressure switch,
ensure that the pressure tube is in good order and clear of obstruction.
IMPORTANT
Ensure the tube from the air bell always goes up to the pressure switch.
Do not use thin wall vacuum tube for replacement.
!
Service Manual XP3 17 Revision 1F